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Auto merge of #134504 - oli-obk:push-rltsvnyttwll, r=compiler-errors

Use trait definition cycle detection for trait alias definitions, too

fixes #133901

In general doing this for `All` is not right, but this code path is specifically for traits and trait aliases, and there we only ever use `All` for trait aliases.
This commit is contained in:
bors 2025-01-16 18:46:28 +00:00
commit 99db2737c9
6 changed files with 72 additions and 8 deletions

View file

@ -653,7 +653,7 @@ pub(super) fn implied_predicates_with_filter<'tcx>(
}
}
}
PredicateFilter::SelfAndAssociatedTypeBounds => {
PredicateFilter::All | PredicateFilter::SelfAndAssociatedTypeBounds => {
for &(pred, span) in implied_bounds {
debug!("superbound: {:?}", pred);
if let ty::ClauseKind::Trait(bound) = pred.kind().skip_binder()

View file

@ -401,7 +401,7 @@ impl<'tcx> Ty<'tcx> {
/// The more specific methods will often optimize their creation.
#[allow(rustc::usage_of_ty_tykind)]
#[inline]
pub fn new(tcx: TyCtxt<'tcx>, st: TyKind<'tcx>) -> Ty<'tcx> {
fn new(tcx: TyCtxt<'tcx>, st: TyKind<'tcx>) -> Ty<'tcx> {
tcx.mk_ty_from_kind(st)
}
@ -613,6 +613,41 @@ impl<'tcx> Ty<'tcx> {
#[inline]
pub fn new_adt(tcx: TyCtxt<'tcx>, def: AdtDef<'tcx>, args: GenericArgsRef<'tcx>) -> Ty<'tcx> {
tcx.debug_assert_args_compatible(def.did(), args);
if cfg!(debug_assertions) {
match tcx.def_kind(def.did()) {
DefKind::Struct | DefKind::Union | DefKind::Enum => {}
DefKind::Mod
| DefKind::Variant
| DefKind::Trait
| DefKind::TyAlias
| DefKind::ForeignTy
| DefKind::TraitAlias
| DefKind::AssocTy
| DefKind::TyParam
| DefKind::Fn
| DefKind::Const
| DefKind::ConstParam
| DefKind::Static { .. }
| DefKind::Ctor(..)
| DefKind::AssocFn
| DefKind::AssocConst
| DefKind::Macro(..)
| DefKind::ExternCrate
| DefKind::Use
| DefKind::ForeignMod
| DefKind::AnonConst
| DefKind::InlineConst
| DefKind::OpaqueTy
| DefKind::Field
| DefKind::LifetimeParam
| DefKind::GlobalAsm
| DefKind::Impl { .. }
| DefKind::Closure
| DefKind::SyntheticCoroutineBody => {
bug!("not an adt: {def:?} ({:?})", tcx.def_kind(def.did()))
}
}
}
Ty::new(tcx, Adt(def, args))
}
@ -772,7 +807,7 @@ impl<'tcx> Ty<'tcx> {
}
}
});
Ty::new(tcx, Adt(adt_def, args))
Ty::new_adt(tcx, adt_def, args)
}
#[inline]

View file

@ -1,7 +1,7 @@
#![feature(trait_alias)]
trait T1 = T2;
//~^ ERROR cycle detected when computing the super predicates of `T1`
//~^ ERROR cycle detected when computing the implied predicates of `T1`
trait T2 = T3;

View file

@ -1,20 +1,20 @@
error[E0391]: cycle detected when computing the super predicates of `T1`
error[E0391]: cycle detected when computing the implied predicates of `T1`
--> $DIR/infinite-trait-alias-recursion.rs:3:12
|
LL | trait T1 = T2;
| ^^
|
note: ...which requires computing the super predicates of `T2`...
note: ...which requires computing the implied predicates of `T2`...
--> $DIR/infinite-trait-alias-recursion.rs:6:12
|
LL | trait T2 = T3;
| ^^
note: ...which requires computing the super predicates of `T3`...
note: ...which requires computing the implied predicates of `T3`...
--> $DIR/infinite-trait-alias-recursion.rs:8:12
|
LL | trait T3 = T1 + T3;
| ^^
= note: ...which again requires computing the super predicates of `T1`, completing the cycle
= note: ...which again requires computing the implied predicates of `T1`, completing the cycle
= note: trait aliases cannot be recursive
note: cycle used when checking that `T1` is well-formed
--> $DIR/infinite-trait-alias-recursion.rs:3:1

View file

@ -0,0 +1,11 @@
//! This test used to get stuck in an infinite
//! recursion during normalization.
//!
//! issue: https://github.com/rust-lang/rust/issues/133901
#![feature(trait_alias)]
fn foo<T: Baz<i32>>() {}
trait Baz<A> = Baz<Option<A>>;
//~^ ERROR: cycle detected when computing the implied predicates of `Baz`
fn main() {}

View file

@ -0,0 +1,18 @@
error[E0391]: cycle detected when computing the implied predicates of `Baz`
--> $DIR/infinite_normalization.rs:8:16
|
LL | trait Baz<A> = Baz<Option<A>>;
| ^^^^^^^^^^^^^^
|
= note: ...which immediately requires computing the implied predicates of `Baz` again
= note: trait aliases cannot be recursive
note: cycle used when computing normalized predicates of `foo`
--> $DIR/infinite_normalization.rs:7:1
|
LL | fn foo<T: Baz<i32>>() {}
| ^^^^^^^^^^^^^^^^^^^^^
= note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
error: aborting due to 1 previous error
For more information about this error, try `rustc --explain E0391`.