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.

Sign up for GitHub

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

Deny capturing late-bound ty/const params in nested opaques #132832

Merged
merged 2 commits into from
Nov 17, 2024
Merged

Deny capturing late-bound ty/const params in nested opaques #132832

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
58abbaf
Revert "Skip late-bound lifetimes when crossing an AnonConst."
compiler-errors Nov 9, 2024
8d871b7
Deny capturing late-bound ty/ct params in nested opaques
compiler-errors Nov 10, 2024
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
51 changes: 29 additions & 22 deletions compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -177,6 +177,7 @@ enum Scope<'a> {
LateBoundary {
s: ScopeRef<'a>,
what: &'static str,
deny_late_regions: bool,
},

Root {
Expand Down Expand Up @@ -234,9 +235,11 @@ impl<'a> fmt::Debug for TruncatedScopeDebug<'a> {
.field("s", &"..")
.finish(),
Scope::TraitRefBoundary { s: _ } => f.debug_struct("TraitRefBoundary").finish(),
Scope::LateBoundary { s: _, what } => {
f.debug_struct("LateBoundary").field("what", what).finish()
}
Scope::LateBoundary { s: _, what, deny_late_regions } => f
.debug_struct("LateBoundary")
.field("what", what)
.field("deny_late_regions", deny_late_regions)
.finish(),
Scope::Root { opt_parent_item } => {
f.debug_struct("Root").field("opt_parent_item", &opt_parent_item).finish()
}
Expand Down Expand Up @@ -573,17 +576,11 @@ impl<'a, 'tcx> Visitor<'tcx> for BoundVarContext<'a, 'tcx> {
// give, we will reverse the IndexMap after early captures.
let mut late_depth = 0;
let mut scope = self.scope;
let mut crossed_late_boundary = None;
let mut opaque_capture_scopes = vec![(opaque.def_id, &captures)];
loop {
match *scope {
Scope::Binder { ref bound_vars, scope_type, s, .. } => {
for (&original_lifetime, &def) in bound_vars.iter().rev() {
if let ResolvedArg::LateBound(..) = def
&& crossed_late_boundary.is_some()
{
continue;
}
if let DefKind::LifetimeParam = self.tcx.def_kind(original_lifetime) {
let def = def.shifted(late_depth);
let ident = lifetime_ident(original_lifetime);
Expand Down Expand Up @@ -624,12 +621,8 @@ impl<'a, 'tcx> Visitor<'tcx> for BoundVarContext<'a, 'tcx> {

Scope::ObjectLifetimeDefault { s, .. }
| Scope::Supertrait { s, .. }
| Scope::TraitRefBoundary { s, .. } => {
scope = s;
}

Scope::LateBoundary { s, what, .. } => {
crossed_late_boundary = Some(what);
| Scope::TraitRefBoundary { s, .. }
| Scope::LateBoundary { s, .. } => {
scope = s;
}
}
Expand All @@ -640,7 +633,16 @@ impl<'a, 'tcx> Visitor<'tcx> for BoundVarContext<'a, 'tcx> {
let scope = Scope::Opaque { captures: &captures, def_id: opaque.def_id, s: self.scope };
self.with(scope, |this| {
let scope = Scope::TraitRefBoundary { s: this.scope };
this.with(scope, |this| intravisit::walk_opaque_ty(this, opaque))
this.with(scope, |this| {
let scope = Scope::LateBoundary {
s: this.scope,
what: "nested `impl Trait`",
// We can capture late-bound regions; we just don't duplicate
// lifetime or const params, so we can't allow those.
deny_late_regions: false,
};
this.with(scope, |this| intravisit::walk_opaque_ty(this, opaque))
})
});

let captures = captures.into_inner().into_iter().collect();
Expand Down Expand Up @@ -997,9 +999,12 @@ impl<'a, 'tcx> Visitor<'tcx> for BoundVarContext<'a, 'tcx> {
}

fn visit_anon_const(&mut self, c: &'tcx hir::AnonConst) {
self.with(Scope::LateBoundary { s: self.scope, what: "constant" }, |this| {
intravisit::walk_anon_const(this, c);
});
self.with(
Scope::LateBoundary { s: self.scope, what: "constant", deny_late_regions: true },
|this| {
intravisit::walk_anon_const(this, c);
},
);
}

fn visit_generic_param(&mut self, p: &'tcx GenericParam<'tcx>) {
Expand Down Expand Up @@ -1291,8 +1296,10 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
scope = s;
}

Scope::LateBoundary { s, what } => {
crossed_late_boundary = Some(what);
Scope::LateBoundary { s, what, deny_late_regions } => {
if deny_late_regions {
crossed_late_boundary = Some(what);
}
scope = s;
}
}
Expand Down Expand Up @@ -1508,7 +1515,7 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
scope = s;
}

Scope::LateBoundary { s, what } => {
Scope::LateBoundary { s, what, deny_late_regions: _ } => {
crossed_late_boundary = Some(what);
scope = s;
}
Expand Down
4 changes: 0 additions & 4 deletions tests/crashes/131535.rs
View file
Open in desktop

This file was deleted.

7 changes: 0 additions & 7 deletions tests/crashes/131637.rs
View file
Open in desktop

This file was deleted.

9 changes: 0 additions & 9 deletions tests/crashes/132530.rs
View file
Open in desktop

This file was deleted.

1 change: 1 addition & 0 deletions tests/ui/type-alias-impl-trait/non-lifetime-binder-in-constraint.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -7,6 +7,7 @@ fn produce() -> impl for<T> Trait<(), Assoc = impl Trait<T>> {
//~^ ERROR associated type `Assoc` not found for `Trait`
//~| ERROR associated type `Assoc` not found for `Trait`
//~| the trait bound `{integer}: Trait<()>` is not satisfied
//~| ERROR cannot capture late-bound type parameter in nested `impl Trait`
16
}

Expand Down
8 changes: 7 additions & 1 deletion tests/ui/type-alias-impl-trait/non-lifetime-binder-in-constraint.stderr
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,3 +1,9 @@
error: cannot capture late-bound type parameter in nested `impl Trait`
--> $DIR/non-lifetime-binder-in-constraint.rs:6:58
|
LL | fn produce() -> impl for<T> Trait<(), Assoc = impl Trait<T>> {
| - parameter defined here ^

error[E0220]: associated type `Assoc` not found for `Trait`
--> $DIR/non-lifetime-binder-in-constraint.rs:6:39
|
Expand Down Expand Up @@ -27,7 +33,7 @@ help: this trait has no implementations, consider adding one
LL | trait Trait<T: ?Sized> {}
| ^^^^^^^^^^^^^^^^^^^^^^

error: aborting due to 3 previous errors
error: aborting due to 4 previous errors

Some errors have detailed explanations: E0220, E0277.
For more information about an error, try `rustc --explain E0220`.
3 changes: 2 additions & 1 deletion tests/ui/type-alias-impl-trait/non-lifetime-binder.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -5,6 +5,7 @@ trait Trait<T> {}

fn f() -> impl for<T> Trait<impl Trait<T>> {}
//~^ ERROR nested `impl Trait` is not allowed
//~| ERROR the trait bound `(): Trait<impl Trait<T>>` is not satisfied
//~| ERROR the trait bound `(): Trait<impl Trait<{type error}>>` is not satisfied
Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This error message sucks, but also it's the same error message we'd get from something like impl Trait<impl Trait<Missing>>, and really has nothing to do with this test other than now we begin resolving the late-bound T to error since it crosses a late-bound scope.

The predicate itself doesn't reference errors, but when we render an opaque using its bounds, we'll render {type error}. We could suppress it, but also I don't think it needs to be fixed here.

//~| ERROR cannot capture late-bound type parameter in nested `impl Trait`

fn main() {}
14 changes: 11 additions & 3 deletions tests/ui/type-alias-impl-trait/non-lifetime-binder.stderr
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -7,19 +7,27 @@ LL | fn f() -> impl for<T> Trait<impl Trait<T>> {}
| | nested `impl Trait` here
| outer `impl Trait`

error[E0277]: the trait bound `(): Trait<impl Trait<T>>` is not satisfied
error: cannot capture late-bound type parameter in nested `impl Trait`
--> $DIR/non-lifetime-binder.rs:6:40
|
LL | fn f() -> impl for<T> Trait<impl Trait<T>> {}
| - ^
| |
| parameter defined here

error[E0277]: the trait bound `(): Trait<impl Trait<{type error}>>` is not satisfied
--> $DIR/non-lifetime-binder.rs:6:11
|
LL | fn f() -> impl for<T> Trait<impl Trait<T>> {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Trait<impl Trait<T>>` is not implemented for `()`
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Trait<impl Trait<{type error}>>` is not implemented for `()`
|
help: this trait has no implementations, consider adding one
--> $DIR/non-lifetime-binder.rs:4:1
|
LL | trait Trait<T> {}
| ^^^^^^^^^^^^^^

error: aborting due to 2 previous errors
error: aborting due to 3 previous errors

Some errors have detailed explanations: E0277, E0666.
For more information about an error, try `rustc --explain E0277`.
Loading