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Report nicer errors for HRTB NLL errors from queries

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This commit is contained in:
Matthew Jasper 2021-06-07 20:25:19 +01:00 • committed by Rémy Rakic
parent 0c388b0261
commit d563a63788
29 changed files with 473 additions and 101 deletions
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13
compiler/rustc_infer/src/infer/mod.rs
View file

@ -1111,7 +1111,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
/// etc) this is the root universe U0. For inference variables or
/// placeholders, however, it will return the universe which which
/// they are associated.
fn universe_of_region(&self, r: ty::Region<'tcx>) -> ty::UniverseIndex {
pub fn universe_of_region(&self, r: ty::Region<'tcx>) -> ty::UniverseIndex {
self.inner.borrow_mut().unwrap_region_constraints().universe(r)
}
@ -1289,6 +1289,17 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
op(inner.unwrap_region_constraints().data())
}
pub fn region_var_origin(&self, vid: ty::RegionVid) -> RegionVariableOrigin {
let mut inner = self.inner.borrow_mut();
let inner = &mut *inner;
inner
.region_constraint_storage
.as_mut()
.expect("regions already resolved")
.with_log(&mut inner.undo_log)
.var_origin(vid)
}
/// Takes ownership of the list of variable regions. This implies
/// that all the region constraints have already been taken, and
/// hence that `resolve_regions_and_report_errors` can never be

5
compiler/rustc_infer/src/infer/region_constraints/mod.rs
View file

@ -445,6 +445,11 @@ impl<'tcx> RegionConstraintCollector<'_, 'tcx> {
self.var_infos[vid].universe
}
/// Returns the origin for the given variable.
pub fn var_origin(&self, vid: RegionVid) -> RegionVariableOrigin {
self.var_infos[vid].origin
}
fn add_constraint(&mut self, constraint: Constraint<'tcx>, origin: SubregionOrigin<'tcx>) {
// cannot add constraints once regions are resolved
debug!("RegionConstraintCollector: add_constraint({:?})", constraint);

252
compiler/rustc_mir/src/borrow_check/diagnostics/bound_region_errors.rs
View file

@ -1,9 +1,14 @@
use rustc_errors::DiagnosticBuilder;
use rustc_infer::infer::canonical::Canonical;
use rustc_infer::traits::ObligationCause;
use rustc_infer::infer::error_reporting::nice_region_error::NiceRegionError;
use rustc_infer::infer::region_constraints::Constraint;
use rustc_infer::infer::{InferCtxt, RegionResolutionError, SubregionOrigin, TyCtxtInferExt as _};
use rustc_infer::traits::{Normalized, Obligation, ObligationCause, TraitEngine, TraitEngineExt};
use rustc_middle::ty::error::TypeError;
use rustc_middle::ty::{self, Ty, TypeFoldable};
use rustc_middle::ty::{self, Ty, TyCtxt, TypeFoldable};
use rustc_span::Span;
use rustc_trait_selection::traits::query::type_op;
use rustc_trait_selection::traits::{SelectionContext, TraitEngineExt as _};
use std::fmt;
use std::rc::Rc;
@ -37,11 +42,10 @@ impl UniverseInfo<'tcx> {
crate fn report_error(
&self,
mbcx: &mut MirBorrowckCtxt<'_, 'tcx>,
_placeholder: ty::PlaceholderRegion,
_error_element: RegionElement,
placeholder: ty::PlaceholderRegion,
error_element: RegionElement,
span: Span,
) {
// FIXME: improve this error message
match self.0 {
UniverseInfoInner::RelateTys { expected, found } => {
let body_id = mbcx.infcx.tcx.hir().local_def_id_to_hir_id(mbcx.mir_def_id());
@ -53,7 +57,13 @@ impl UniverseInfo<'tcx> {
);
err.buffer(&mut mbcx.errors_buffer);
}
UniverseInfoInner::TypeOp(_) | UniverseInfoInner::Other => {
UniverseInfoInner::TypeOp(ref type_op_info) => {
type_op_info.report_error(mbcx, placeholder, error_element, span);
}
UniverseInfoInner::Other => {
// FIXME: This error message isn't great, but it doesn't show
// up in the existing UI tests. Consider investigating this
// some more.
mbcx.infcx
.tcx
.sess
@ -73,8 +83,8 @@ impl<'tcx> ToUniverseInfo<'tcx>
{
fn to_universe_info(self, base_universe: ty::UniverseIndex) -> UniverseInfo<'tcx> {
UniverseInfo(UniverseInfoInner::TypeOp(Rc::new(PredicateQuery {
_canonical_query: self,
_base_universe: base_universe,
canonical_query: self,
base_universe,
})))
}
}
@ -84,8 +94,8 @@ impl<'tcx, T: Copy + fmt::Display + TypeFoldable<'tcx> + 'tcx> ToUniverseInfo<'t
{
fn to_universe_info(self, base_universe: ty::UniverseIndex) -> UniverseInfo<'tcx> {
UniverseInfo(UniverseInfoInner::TypeOp(Rc::new(NormalizeQuery {
_canonical_query: self,
_base_universe: base_universe,
canonical_query: self,
base_universe,
})))
}
}
@ -109,23 +119,229 @@ impl<'tcx, F, G> ToUniverseInfo<'tcx> for Canonical<'tcx, type_op::custom::Custo
#[allow(unused_lifetimes)]
trait TypeOpInfo<'tcx> {
// TODO: Methods for rerunning type op and reporting an error
/// Returns an rrror to be reported if rerunning the type op fails to
/// recover the error's cause.
fn fallback_error(&self, tcx: TyCtxt<'tcx>, span: Span) -> DiagnosticBuilder<'tcx>;
fn base_universe(&self) -> ty::UniverseIndex;
fn nice_error(
&self,
tcx: TyCtxt<'tcx>,
span: Span,
placeholder_region: ty::Region<'tcx>,
error_region: Option<ty::Region<'tcx>>,
) -> Option<DiagnosticBuilder<'tcx>>;
fn report_error(
&self,
mbcx: &mut MirBorrowckCtxt<'_, 'tcx>,
placeholder: ty::PlaceholderRegion,
error_element: RegionElement,
span: Span,
) {
let tcx = mbcx.infcx.tcx;
let base_universe = self.base_universe();
let adjusted_universe = if let Some(adjusted) =
placeholder.universe.as_u32().checked_sub(base_universe.as_u32())
{
adjusted
} else {
self.fallback_error(tcx, span).buffer(&mut mbcx.errors_buffer);
return;
};
let placeholder_region = tcx.mk_region(ty::RePlaceholder(ty::Placeholder {
name: placeholder.name,
universe: adjusted_universe.into(),
}));
let error_region =
if let RegionElement::PlaceholderRegion(error_placeholder) = error_element {
let adjusted_universe =
error_placeholder.universe.as_u32().checked_sub(base_universe.as_u32());
adjusted_universe.map(|adjusted| {
tcx.mk_region(ty::RePlaceholder(ty::Placeholder {
name: error_placeholder.name,
universe: adjusted.into(),
}))
})
} else {
None
};
debug!(?placeholder_region);
let nice_error = self.nice_error(tcx, span, placeholder_region, error_region);
if let Some(nice_error) = nice_error {
nice_error.buffer(&mut mbcx.errors_buffer);
} else {
self.fallback_error(tcx, span).buffer(&mut mbcx.errors_buffer);
}
}
}
struct PredicateQuery<'tcx> {
_canonical_query:
canonical_query:
Canonical<'tcx, ty::ParamEnvAnd<'tcx, type_op::prove_predicate::ProvePredicate<'tcx>>>,
_base_universe: ty::UniverseIndex,
base_universe: ty::UniverseIndex,
}
impl TypeOpInfo<'tcx> for PredicateQuery<'tcx> {}
impl TypeOpInfo<'tcx> for PredicateQuery<'tcx> {
fn fallback_error(&self, tcx: TyCtxt<'tcx>, span: Span) -> DiagnosticBuilder<'tcx> {
let mut err = tcx.sess.struct_span_err(span, "higher-ranked lifetime error");
err.note(&format!("could not prove {}", self.canonical_query.value.value.predicate));
err
}
fn base_universe(&self) -> ty::UniverseIndex {
self.base_universe
}
fn nice_error(
&self,
tcx: TyCtxt<'tcx>,
span: Span,
placeholder_region: ty::Region<'tcx>,
error_region: Option<ty::Region<'tcx>>,
) -> Option<DiagnosticBuilder<'tcx>> {
tcx.infer_ctxt().enter_with_canonical(span, &self.canonical_query, |ref infcx, key, _| {
let mut fulfill_cx = TraitEngine::new(tcx);
let (param_env, prove_predicate) = key.into_parts();
fulfill_cx.register_predicate_obligation(
infcx,
Obligation::new(
ObligationCause::dummy_with_span(span),
param_env,
prove_predicate.predicate,
),
);
try_extract_error_from_fulfill_cx(fulfill_cx, infcx, placeholder_region, error_region)
})
}
}
struct NormalizeQuery<'tcx, T> {
_canonical_query: Canonical<'tcx, ty::ParamEnvAnd<'tcx, type_op::Normalize<T>>>,
_base_universe: ty::UniverseIndex,
canonical_query: Canonical<'tcx, ty::ParamEnvAnd<'tcx, type_op::Normalize<T>>>,
base_universe: ty::UniverseIndex,
}
impl<T> TypeOpInfo<'tcx> for NormalizeQuery<'tcx, T> where
T: Copy + fmt::Display + TypeFoldable<'tcx> + 'tcx
impl<T> TypeOpInfo<'tcx> for NormalizeQuery<'tcx, T>
where
T: Copy + fmt::Display + TypeFoldable<'tcx> + 'tcx,
{
fn fallback_error(&self, tcx: TyCtxt<'tcx>, span: Span) -> DiagnosticBuilder<'tcx> {
let mut err = tcx.sess.struct_span_err(span, "higher-ranked lifetime error");
err.note(&format!("could not normalize `{}`", self.canonical_query.value.value.value));
err
}
fn base_universe(&self) -> ty::UniverseIndex {
self.base_universe
}
fn nice_error(
&self,
tcx: TyCtxt<'tcx>,
span: Span,
placeholder_region: ty::Region<'tcx>,
error_region: Option<ty::Region<'tcx>>,
) -> Option<DiagnosticBuilder<'tcx>> {
tcx.infer_ctxt().enter_with_canonical(span, &self.canonical_query, |ref infcx, key, _| {
let mut fulfill_cx = TraitEngine::new(tcx);
let mut selcx = SelectionContext::new(infcx);
let (param_env, value) = key.into_parts();
let Normalized { value: _, obligations } = rustc_trait_selection::traits::normalize(
&mut selcx,
param_env,
ObligationCause::dummy_with_span(span),
value.value,
);
fulfill_cx.register_predicate_obligations(infcx, obligations);
try_extract_error_from_fulfill_cx(fulfill_cx, infcx, placeholder_region, error_region)
})
}
}
fn try_extract_error_from_fulfill_cx<'tcx>(
mut fulfill_cx: Box<dyn TraitEngine<'tcx> + 'tcx>,
infcx: &InferCtxt<'_, 'tcx>,
placeholder_region: ty::Region<'tcx>,
error_region: Option<ty::Region<'tcx>>,
) -> Option<DiagnosticBuilder<'tcx>> {
let tcx = infcx.tcx;
// We generally shouldn't have here because the query was
// already run, but there's no point using `delay_span_bug`
// when we're going to emit an error here anyway.
let _errors = fulfill_cx.select_all_or_error(infcx).err().unwrap_or_else(Vec::new);
let region_obligations = infcx.take_registered_region_obligations();
debug!(?region_obligations);
let (sub_region, cause) = infcx.with_region_constraints(|region_constraints| {
debug!(?region_constraints);
region_constraints.constraints.iter().find_map(|(constraint, cause)| {
match *constraint {
Constraint::RegSubReg(sub, sup) if sup == placeholder_region && sup != sub => {
Some((sub, cause.clone()))
}
// FIXME: Should this check the universe of the var?
Constraint::VarSubReg(vid, sup) if sup == placeholder_region => {
Some((tcx.mk_region(ty::ReVar(vid)), cause.clone()))
}
_ => None,
}
})
})?;
debug!(?sub_region, ?cause);
let nice_error = match (error_region, sub_region) {
(Some(error_region), &ty::ReVar(vid)) => NiceRegionError::new(
infcx,
RegionResolutionError::SubSupConflict(
vid,
infcx.region_var_origin(vid),
cause.clone(),
error_region,
cause.clone(),
placeholder_region,
),
),
(Some(error_region), _) => NiceRegionError::new(
infcx,
RegionResolutionError::ConcreteFailure(cause.clone(), error_region, placeholder_region),
),
// Note universe here is wrong...
(None, &ty::ReVar(vid)) => NiceRegionError::new(
infcx,
RegionResolutionError::UpperBoundUniverseConflict(
vid,
infcx.region_var_origin(vid),
infcx.universe_of_region(sub_region),
cause.clone(),
placeholder_region,
),
),
(None, _) => NiceRegionError::new(
infcx,
RegionResolutionError::ConcreteFailure(cause.clone(), sub_region, placeholder_region),
),
};
nice_error.try_report_from_nll().or_else(|| {
if let SubregionOrigin::Subtype(trace) = cause {
Some(
infcx.report_and_explain_type_error(*trace, &TypeError::RegionsPlaceholderMismatch),
)
} else {
None
}
})
}

8
src/test/ui/associated-types/higher-ranked-projection.bad.nll.stderr
View file

@ -1,8 +1,12 @@
error: higher-ranked subtype error
error[E0308]: mismatched types
--> $DIR/higher-ranked-projection.rs:25:5
|
LL | foo(());
| ^^^^^^^
| ^^^^^^^ one type is more general than the other
|
= note: expected type `&'a ()`
found reference `&()`
error: aborting due to previous error
For more information about this error, try `rustc --explain E0308`.

14
src/test/ui/generator/auto-trait-regions.nll.stderr
View file

@ -24,17 +24,23 @@ LL | assert_foo(a);
|
= note: consider using a `let` binding to create a longer lived value
error: higher-ranked subtype error
error: implementation of `Foo` is not general enough
--> $DIR/auto-trait-regions.rs:31:5
|
LL | assert_foo(gen);
| ^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^ implementation of `Foo` is not general enough
|
= note: `&'0 OnlyFooIfStaticRef` must implement `Foo`, for any lifetime `'0`...
= note: ...but `Foo` is actually implemented for the type `&'static OnlyFooIfStaticRef`
error: higher-ranked subtype error
error: implementation of `Foo` is not general enough
--> $DIR/auto-trait-regions.rs:50:5
|
LL | assert_foo(gen);
| ^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^ implementation of `Foo` is not general enough
|
= note: `Foo` would have to be implemented for the type `A<'0, '1>`, for any two lifetimes `'0` and `'1`...
= note: ...but `Foo` is actually implemented for the type `A<'_, '2>`, for some specific lifetime `'2`
error: aborting due to 4 previous errors

8
src/test/ui/generator/resume-arg-late-bound.nll.stderr
View file

@ -1,8 +1,12 @@
error: higher-ranked subtype error
error[E0308]: mismatched types
--> $DIR/resume-arg-late-bound.rs:15:5
|
LL | test(gen);
| ^^^^^^^^^
| ^^^^^^^^^ one type is more general than the other
|
= note: expected type `for<'a> Generator<&'a mut bool>`
found type `Generator<&mut bool>`
error: aborting due to previous error
For more information about this error, try `rustc --explain E0308`.

2
src/test/ui/higher-rank-trait-bounds/issue-59311.rs
View file

@ -14,7 +14,7 @@ pub fn crash<V>(v: &V)
where
for<'a> &'a V: T + 'static,
{
v.t(|| {}); //~ ERROR: higher-ranked subtype error
v.t(|| {}); //~ ERROR: higher-ranked lifetime error
}
fn main() {}

4
src/test/ui/higher-rank-trait-bounds/issue-59311.stderr
View file

@ -1,8 +1,10 @@
error: higher-ranked subtype error
error: higher-ranked lifetime error
--> $DIR/issue-59311.rs:17:9
|
LL | v.t(|| {});
| ^^^^^
|
= note: could not prove for<'a> &'a V: 'static
error: aborting due to previous error

14
src/test/ui/hrtb/hrtb-conflate-regions.nll.stderr
View file

@ -1,14 +1,20 @@
error: higher-ranked subtype error
error: implementation of `Foo` is not general enough
--> $DIR/hrtb-conflate-regions.rs:27:10
|
LL | fn b() { want_foo2::<SomeStruct>(); }
| ^^^^^^^^^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^^^^^^^^^^ implementation of `Foo` is not general enough
|
= note: `SomeStruct` must implement `Foo<(&'0 isize, &'1 isize)>`, for any two lifetimes `'0` and `'1`...
= note: ...but it actually implements `Foo<(&'2 isize, &'2 isize)>`, for some specific lifetime `'2`
error: higher-ranked subtype error
error: implementation of `Foo` is not general enough
--> $DIR/hrtb-conflate-regions.rs:27:10
|
LL | fn b() { want_foo2::<SomeStruct>(); }
| ^^^^^^^^^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^^^^^^^^^^ implementation of `Foo` is not general enough
|
= note: `SomeStruct` must implement `Foo<(&'0 isize, &'1 isize)>`, for any two lifetimes `'0` and `'1`...
= note: ...but it actually implements `Foo<(&'2 isize, &'2 isize)>`, for some specific lifetime `'2`
error: aborting due to 2 previous errors

7
src/test/ui/hrtb/hrtb-exists-forall-trait-contravariant.nll.stderr
View file

@ -1,8 +1,11 @@
error: higher-ranked subtype error
error: implementation of `Trait` is not general enough
--> $DIR/hrtb-exists-forall-trait-contravariant.rs:34:5
|
LL | foo::<()>();
| ^^^^^^^^^^^
| ^^^^^^^^^^^ implementation of `Trait` is not general enough
|
= note: `()` must implement `Trait<for<'b> fn(&'b u32)>`
= note: ...but it actually implements `Trait<fn(&'0 u32)>`, for some specific lifetime `'0`
error: aborting due to previous error

7
src/test/ui/hrtb/hrtb-exists-forall-trait-invariant.nll.stderr
View file

@ -1,8 +1,11 @@
error: higher-ranked subtype error
error: implementation of `Trait` is not general enough
--> $DIR/hrtb-exists-forall-trait-invariant.rs:28:5
|
LL | foo::<()>();
| ^^^^^^^^^^^
| ^^^^^^^^^^^ implementation of `Trait` is not general enough
|
= note: `()` must implement `Trait<for<'b> fn(Cell<&'b u32>)>`
= note: ...but it actually implements `Trait<fn(Cell<&'0 u32>)>`, for some specific lifetime `'0`
error: aborting due to previous error

7
src/test/ui/hrtb/hrtb-just-for-static.nll.stderr
View file

@ -1,8 +1,11 @@
error: higher-ranked subtype error
error: implementation of `Foo` is not general enough
--> $DIR/hrtb-just-for-static.rs:24:5
|
LL | want_hrtb::<StaticInt>()
| ^^^^^^^^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^^^^^^^^^ implementation of `Foo` is not general enough
|
= note: `StaticInt` must implement `Foo<&'0 isize>`, for any lifetime `'0`...
= note: ...but it actually implements `Foo<&'static isize>`
error: lifetime may not live long enough
--> $DIR/hrtb-just-for-static.rs:30:5

7
src/test/ui/hrtb/hrtb-perfect-forwarding.nll.stderr
View file

@ -57,11 +57,14 @@ LL | foo_hrtb_bar_not(&mut t);
|
= help: consider replacing `'b` with `'static`
error: higher-ranked subtype error
error: implementation of `Bar` is not general enough
--> $DIR/hrtb-perfect-forwarding.rs:43:5
|
LL | foo_hrtb_bar_not(&mut t);
| ^^^^^^^^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^^^^^^^^^ implementation of `Bar` is not general enough
|
= note: `T` must implement `Bar<&'0 isize>`, for any lifetime `'0`...
= note: ...but it actually implements `Bar<&'1 isize>`, for some specific lifetime `'1`
warning: function cannot return without recursing
--> $DIR/hrtb-perfect-forwarding.rs:48:1

7
src/test/ui/hrtb/issue-46989.nll.stderr
View file

@ -1,8 +1,11 @@
error: higher-ranked subtype error
error: implementation of `Foo` is not general enough
--> $DIR/issue-46989.rs:38:5
|
LL | assert_foo::<fn(&i32)>();
| ^^^^^^^^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^^^^^^^^^ implementation of `Foo` is not general enough
|
= note: `Foo` would have to be implemented for the type `for<'r> fn(&'r i32)`
= note: ...but `Foo` is actually implemented for the type `fn(&'0 i32)`, for some specific lifetime `'0`
error: aborting due to previous error

15
src/test/ui/issues/issue-40000.nll.stderr
View file

@ -1,14 +1,21 @@
error: higher-ranked subtype error
error[E0308]: mismatched types
--> $DIR/issue-40000.rs:6:9
|
LL | foo(bar);
| ^^^
| ^^^ one type is more general than the other
|
= note: expected trait object `dyn for<'r> Fn(&'r i32)`
found trait object `dyn Fn(&i32)`
error: higher-ranked subtype error
error[E0308]: mismatched types
--> $DIR/issue-40000.rs:6:9
|
LL | foo(bar);
| ^^^
| ^^^ one type is more general than the other
|
= note: expected trait object `dyn for<'r> Fn(&'r i32)`
found trait object `dyn Fn(&i32)`
error: aborting due to 2 previous errors
For more information about this error, try `rustc --explain E0308`.

28
src/test/ui/issues/issue-54302-cases.nll.stderr
View file

@ -1,26 +1,38 @@
error: higher-ranked subtype error
error: implementation of `Foo` is not general enough
--> $DIR/issue-54302-cases.rs:63:5
|
LL | <u32 as RefFoo<u32>>::ref_foo(a)
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ implementation of `Foo` is not general enough
|
= note: `Foo<'static, u32>` would have to be implemented for the type `&'0 u32`, for any lifetime `'0`...
= note: ...but `Foo<'_, u32>` is actually implemented for the type `&'1 u32`, for some specific lifetime `'1`
error: higher-ranked subtype error
error: implementation of `Foo` is not general enough
--> $DIR/issue-54302-cases.rs:69:5
|
LL | <i32 as RefFoo<i32>>::ref_foo(a)
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ implementation of `Foo` is not general enough
|
= note: `Foo<'static, i32>` would have to be implemented for the type `&'0 i32`, for any lifetime `'0`...
= note: ...but `Foo<'_, i32>` is actually implemented for the type `&'1 i32`, for some specific lifetime `'1`
error: higher-ranked subtype error
error: implementation of `Foo` is not general enough
--> $DIR/issue-54302-cases.rs:75:5
|
LL | <u64 as RefFoo<u64>>::ref_foo(a)
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ implementation of `Foo` is not general enough
|
= note: `Foo<'static, u64>` would have to be implemented for the type `&'0 u64`, for any lifetime `'0`...
= note: ...but `Foo<'_, u64>` is actually implemented for the type `&'1 u64`, for some specific lifetime `'1`
error: higher-ranked subtype error
error: implementation of `Foo` is not general enough
--> $DIR/issue-54302-cases.rs:81:5
|
LL | <i64 as RefFoo<i64>>::ref_foo(a)
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ implementation of `Foo` is not general enough
|
= note: `Foo<'static, i64>` would have to be implemented for the type `&'0 i64`, for any lifetime `'0`...
= note: ...but `Foo<'_, i64>` is actually implemented for the type `&'1 i64`, for some specific lifetime `'1`
error: aborting due to 4 previous errors

7
src/test/ui/issues/issue-55731.nll.stderr
View file

@ -1,11 +1,14 @@
error: higher-ranked subtype error
error: implementation of `DistributedIteratorMulti` is not general enough
--> $DIR/issue-55731.rs:48:5
|
LL | / multi(Map {
LL | | i: Cloned(PhantomData),
LL | | f: X,
LL | | });
| |______^
| |______^ implementation of `DistributedIteratorMulti` is not general enough
|
= note: `DistributedIteratorMulti<&'0 ()>` would have to be implemented for the type `Cloned<&()>`, for any lifetime `'0`...
= note: ...but `DistributedIteratorMulti<&'1 ()>` is actually implemented for the type `Cloned<&'1 ()>`, for some specific lifetime `'1`
error: aborting due to previous error

7
src/test/ui/issues/issue-57843.nll.stderr
View file

@ -1,8 +1,11 @@
error: higher-ranked subtype error
error: implementation of `FnOnce` is not general enough
--> $DIR/issue-57843.rs:25:9
|
LL | Foo(Box::new(|_| ()));
| ^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^ implementation of `FnOnce` is not general enough
|
= note: closure with signature `fn(&'2 bool)` must implement `FnOnce<(&'1 bool,)>`, for any lifetime `'1`...
= note: ...but it actually implements `FnOnce<(&'2 bool,)>`, for some specific lifetime `'2`
error: aborting due to previous error

34
src/test/ui/lifetimes/issue-79187-2.nll.stderr
View file

@ -16,29 +16,47 @@ LL | take_foo(|a: &i32| -> &i32 { a });
| | let's call the lifetime of this reference `'2`
| let's call the lifetime of this reference `'1`
error: higher-ranked subtype error
error: implementation of `FnOnce` is not general enough
--> $DIR/issue-79187-2.rs:8:5
|
LL | take_foo(|a| a);
| ^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^ implementation of `FnOnce` is not general enough
|
= note: closure with signature `fn(&'2 i32) -> &i32` must implement `FnOnce<(&'1 i32,)>`, for any lifetime `'1`...
= note: ...but it actually implements `FnOnce<(&'2 i32,)>`, for some specific lifetime `'2`
error: higher-ranked subtype error
error[E0308]: mismatched types
--> $DIR/issue-79187-2.rs:8:5
|
LL | take_foo(|a| a);
| ^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^ one type is more general than the other
|
= note: expected type `for<'r> Fn<(&'r i32,)>`
found type `Fn<(&i32,)>`
note: this closure does not fulfill the lifetime requirements
--> $DIR/issue-79187-2.rs:8:14
|
LL | take_foo(|a| a);
| ^^^^^
error: higher-ranked subtype error
error[E0308]: mismatched types
--> $DIR/issue-79187-2.rs:9:5
|
LL | take_foo(|a: &i32| a);
| ^^^^^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^^^^^^ one type is more general than the other
|
= note: expected reference `&i32`
found reference `&i32`
error: higher-ranked subtype error
error[E0308]: mismatched types
--> $DIR/issue-79187-2.rs:10:5
|
LL | take_foo(|a: &i32| -> &i32 { a });
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ one type is more general than the other
|
= note: expected reference `&i32`
found reference `&i32`
error: aborting due to 6 previous errors
For more information about this error, try `rustc --explain E0308`.

20
src/test/ui/lifetimes/issue-79187.nll.stderr
View file

@ -1,14 +1,26 @@
error: higher-ranked subtype error
error[E0308]: mismatched types
--> $DIR/issue-79187.rs:5:5
|
LL | thing(f);
| ^^^^^^^^
| ^^^^^^^^ one type is more general than the other
|
= note: expected type `for<'r> FnOnce<(&'r u32,)>`
found type `FnOnce<(&u32,)>`
note: this closure does not fulfill the lifetime requirements
--> $DIR/issue-79187.rs:4:13
|
LL | let f = |_| ();
| ^^^^^^
error: higher-ranked subtype error
error: implementation of `FnOnce` is not general enough
--> $DIR/issue-79187.rs:5:5
|
LL | thing(f);
| ^^^^^^^^
| ^^^^^^^^ implementation of `FnOnce` is not general enough
|
= note: closure with signature `fn(&'2 u32)` must implement `FnOnce<(&'1 u32,)>`, for any lifetime `'1`...
= note: ...but it actually implements `FnOnce<(&'2 u32,)>`, for some specific lifetime `'2`
error: aborting due to 2 previous errors
For more information about this error, try `rustc --explain E0308`.

15
src/test/ui/lub-glb/old-lub-glb-object.nll.stderr
View file

@ -1,14 +1,21 @@
error: higher-ranked subtype error
error[E0308]: mismatched types
--> $DIR/old-lub-glb-object.rs:10:14
|
LL | _ => y,
| ^
| ^ one type is more general than the other
|
= note: expected trait object `dyn for<'r, 's> Foo<&'r u8, &'s u8>`
found trait object `dyn for<'r> Foo<&'r u8, &'r u8>`
error: higher-ranked subtype error
error[E0308]: mismatched types
--> $DIR/old-lub-glb-object.rs:10:14
|
LL | _ => y,
| ^
| ^ one type is more general than the other
|
= note: expected trait object `dyn for<'r, 's> Foo<&'r u8, &'s u8>`
found trait object `dyn for<'r> Foo<&'r u8, &'r u8>`
error: aborting due to 2 previous errors
For more information about this error, try `rustc --explain E0308`.

20
src/test/ui/mismatched_types/closure-mismatch.nll.stderr
View file

@ -1,14 +1,26 @@
error: higher-ranked subtype error
error: implementation of `FnOnce` is not general enough
--> $DIR/closure-mismatch.rs:8:5
|
LL | baz(|_| ());
| ^^^^^^^^^^^
| ^^^^^^^^^^^ implementation of `FnOnce` is not general enough
|
= note: closure with signature `fn(&'2 ())` must implement `FnOnce<(&'1 (),)>`, for any lifetime `'1`...
= note: ...but it actually implements `FnOnce<(&'2 (),)>`, for some specific lifetime `'2`
error: higher-ranked subtype error
error[E0308]: mismatched types
--> $DIR/closure-mismatch.rs:8:5
|
LL | baz(|_| ());
| ^^^^^^^^^^^
| ^^^^^^^^^^^ one type is more general than the other
|
= note: expected type `for<'r> Fn<(&'r (),)>`
found type `Fn<(&(),)>`
note: this closure does not fulfill the lifetime requirements
--> $DIR/closure-mismatch.rs:8:9
|
LL | baz(|_| ());
| ^^^^^^
error: aborting due to 2 previous errors
For more information about this error, try `rustc --explain E0308`.

4
src/test/ui/nll/relate_tys/impl-fn-ignore-binder-via-bottom.rs
View file

@ -30,6 +30,6 @@ impl<T> Y for fn(T) {
fn main() {
let _x = <fn(&())>::make_f();
//~^ higher-ranked subtype error
//~| higher-ranked subtype error
//~^ ERROR implementation of `Y` is not general enough
//~| ERROR implementation of `Y` is not general enough
}

14
src/test/ui/nll/relate_tys/impl-fn-ignore-binder-via-bottom.stderr
View file

@ -1,14 +1,20 @@
error: higher-ranked subtype error
error: implementation of `Y` is not general enough
--> $DIR/impl-fn-ignore-binder-via-bottom.rs:32:14
|
LL | let _x = <fn(&())>::make_f();
| ^^^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^^^^ implementation of `Y` is not general enough
|
= note: `Y` would have to be implemented for the type `for<'r> fn(&'r ())`
= note: ...but `Y` is actually implemented for the type `fn(&'0 ())`, for some specific lifetime `'0`
error: higher-ranked subtype error
error: implementation of `Y` is not general enough
--> $DIR/impl-fn-ignore-binder-via-bottom.rs:32:14
|
LL | let _x = <fn(&())>::make_f();
| ^^^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^^^^ implementation of `Y` is not general enough
|
= note: `Y` would have to be implemented for the type `for<'r> fn(&'r ())`
= note: ...but `Y` is actually implemented for the type `fn(&'0 ())`, for some specific lifetime `'0`
error: aborting due to 2 previous errors

2
src/test/ui/nll/relate_tys/trait-hrtb.rs
View file

@ -12,5 +12,5 @@ fn make_foo<'a>() -> Box<dyn Foo<'a>> {
fn main() {
let x: Box<dyn Foo<'static>> = make_foo();
let y: Box<dyn for<'a> Foo<'a>> = x; //~ ERROR higher-ranked subtype error
let y: Box<dyn for<'a> Foo<'a>> = x; //~ ERROR mismatched types [E0308]
}

8
src/test/ui/nll/relate_tys/trait-hrtb.stderr
View file

@ -1,8 +1,12 @@
error: higher-ranked subtype error
error[E0308]: mismatched types
--> $DIR/trait-hrtb.rs:15:39
|
LL | let y: Box<dyn for<'a> Foo<'a>> = x;
| ^
| ^ one type is more general than the other
|
= note: expected trait object `dyn for<'r> Foo<'r>`
found trait object `dyn Foo<'_>`
error: aborting due to previous error
For more information about this error, try `rustc --explain E0308`.

31
src/test/ui/rfc1623.nll.stderr
View file

@ -19,7 +19,7 @@ LL | struct SomeStruct<'x, 'y, 'z: 'x> {
= note: required because it appears within the type `&SomeStruct`
= note: shared static variables must have a type that implements `Sync`
error: higher-ranked subtype error
error[E0308]: mismatched types
--> $DIR/rfc1623.rs:21:35
|
LL | static SOME_STRUCT: &SomeStruct = &SomeStruct {
@ -29,9 +29,12 @@ LL | | bar: &Bar { bools: &[true, true] },
LL | | f: &id,
LL | |
LL | | };
| |_^
| |_^ one type is more general than the other
|
= note: expected type `for<'r, 's> Fn<(&'r Foo<'s>,)>`
found type `Fn<(&Foo<'_>,)>`
error: higher-ranked subtype error
error[E0308]: mismatched types
--> $DIR/rfc1623.rs:21:35
|
LL | static SOME_STRUCT: &SomeStruct = &SomeStruct {
@ -41,9 +44,12 @@ LL | | bar: &Bar { bools: &[true, true] },
LL | | f: &id,
LL | |
LL | | };
| |_^
| |_^ one type is more general than the other
|
= note: expected type `for<'r, 's> Fn<(&'r Foo<'s>,)>`
found type `Fn<(&Foo<'_>,)>`
error: higher-ranked subtype error
error: implementation of `FnOnce` is not general enough
--> $DIR/rfc1623.rs:21:35
|
LL | static SOME_STRUCT: &SomeStruct = &SomeStruct {
@ -53,9 +59,12 @@ LL | | bar: &Bar { bools: &[true, true] },
LL | | f: &id,
LL | |
LL | | };
| |_^
| |_^ implementation of `FnOnce` is not general enough
|
= note: `fn(&'2 Foo<'_>) -> &'2 Foo<'_> {id::<&'2 Foo<'_>>}` must implement `FnOnce<(&'1 Foo<'_>,)>`, for any lifetime `'1`...
= note: ...but it actually implements `FnOnce<(&'2 Foo<'_>,)>`, for some specific lifetime `'2`
error: higher-ranked subtype error
error: implementation of `FnOnce` is not general enough
--> $DIR/rfc1623.rs:21:35
|
LL | static SOME_STRUCT: &SomeStruct = &SomeStruct {
@ -65,8 +74,12 @@ LL | | bar: &Bar { bools: &[true, true] },
LL | | f: &id,
LL | |
LL | | };
| |_^
| |_^ implementation of `FnOnce` is not general enough
|
= note: `fn(&Foo<'2>) -> &Foo<'2> {id::<&Foo<'2>>}` must implement `FnOnce<(&Foo<'1>,)>`, for any lifetime `'1`...
= note: ...but it actually implements `FnOnce<(&Foo<'2>,)>`, for some specific lifetime `'2`
error: aborting due to 5 previous errors
For more information about this error, try `rustc --explain E0277`.
Some errors have detailed explanations: E0277, E0308.
For more information about an error, try `rustc --explain E0277`.

7
src/test/ui/unboxed-closures/issue-30906.nll.stderr
View file

@ -1,8 +1,11 @@
error: higher-ranked subtype error
error: implementation of `FnOnce` is not general enough
--> $DIR/issue-30906.rs:18:5
|
LL | test(Compose(f, |_| {}));
| ^^^^^^^^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^^^^^^^^^ implementation of `FnOnce` is not general enough
|
= note: `fn(&'2 str) -> T` must implement `FnOnce<(&'1 str,)>`, for any lifetime `'1`...
= note: ...but it actually implements `FnOnce<(&'2 str,)>`, for some specific lifetime `'2`
error: aborting due to previous error

7
src/test/ui/where-clauses/where-for-self-2.nll.stderr
View file

@ -1,8 +1,11 @@
error: higher-ranked subtype error
error: implementation of `Bar` is not general enough
--> $DIR/where-for-self-2.rs:23:5
|
LL | foo(&X);
| ^^^^^^^
| ^^^^^^^ implementation of `Bar` is not general enough
|
= note: `&'0 u32` must implement `Bar`, for any lifetime `'0`...
= note: ...but `Bar` is actually implemented for the type `&'static u32`
error: aborting due to previous error