diff --git a/tests/ui/dyn-star/param-env-region-infer.current.stderr b/tests/ui/dyn-star/param-env-region-infer.current.stderr index 902053ecfef6..b982be451967 100644 --- a/tests/ui/dyn-star/param-env-region-infer.current.stderr +++ b/tests/ui/dyn-star/param-env-region-infer.current.stderr @@ -1,5 +1,5 @@ error[E0282]: type annotations needed - --> $DIR/param-env-region-infer.rs:18:10 + --> $DIR/param-env-region-infer.rs:19:10 | LL | t as _ | ^ cannot infer type diff --git a/tests/ui/dyn-star/param-env-region-infer.next.stderr b/tests/ui/dyn-star/param-env-region-infer.next.stderr deleted file mode 100644 index 28aec533a006..000000000000 --- a/tests/ui/dyn-star/param-env-region-infer.next.stderr +++ /dev/null @@ -1,30 +0,0 @@ -error[E0391]: cycle detected when computing type of `make_dyn_star::{opaque#0}` - --> $DIR/param-env-region-infer.rs:16:60 - | -LL | fn make_dyn_star<'a, T: PointerLike + Debug + 'a>(t: T) -> impl PointerLike + Debug + 'a { - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ - | -note: ...which requires type-checking `make_dyn_star`... - --> $DIR/param-env-region-infer.rs:16:1 - | -LL | fn make_dyn_star<'a, T: PointerLike + Debug + 'a>(t: T) -> impl PointerLike + Debug + 'a { - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ - = note: ...which requires computing layout of `make_dyn_star::{opaque#0}`... - = note: ...which requires normalizing `make_dyn_star::{opaque#0}`... - = note: ...which again requires computing type of `make_dyn_star::{opaque#0}`, completing the cycle -note: cycle used when checking item types in top-level module - --> $DIR/param-env-region-infer.rs:10:1 - | -LL | / #![feature(dyn_star, pointer_like_trait)] -LL | | #![allow(incomplete_features)] -LL | | -LL | | use std::fmt::Debug; -... | -LL | | -LL | | fn main() {} - | |____________^ - = 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 previous error - -For more information about this error, try `rustc --explain E0391`. diff --git a/tests/ui/dyn-star/param-env-region-infer.rs b/tests/ui/dyn-star/param-env-region-infer.rs index 537473abc3a5..50dec94d25b3 100644 --- a/tests/ui/dyn-star/param-env-region-infer.rs +++ b/tests/ui/dyn-star/param-env-region-infer.rs @@ -1,9 +1,10 @@ -// revisions: current next -// Need `-Zdeduplicate-diagnostics=yes` because the number of cycle errors -// emitted is for some horrible reason platform-specific. -//[next] compile-flags: -Ztrait-solver=next -Zdeduplicate-diagnostics=yes +// revisions: current // incremental +// FIXME(-Ztrait-solver=next): THis currently results in unstable query results: +// `normalizes-to(opaque, opaque)` changes from `Maybe(Ambiguous)` to `Maybe(Overflow)` +// once the hidden type of the opaque is already defined to be itself. + // checks that we don't ICE if there are region inference variables in the environment // when computing `PointerLike` builtin candidates. diff --git a/tests/ui/traits/new-solver/coinduction/fixpoint-exponential-growth.rs b/tests/ui/traits/new-solver/coinduction/fixpoint-exponential-growth.rs new file mode 100644 index 000000000000..fcafdcf637a8 --- /dev/null +++ b/tests/ui/traits/new-solver/coinduction/fixpoint-exponential-growth.rs @@ -0,0 +1,32 @@ +// compile-flags: -Ztrait-solver=next + +// Proving `W: Trait` instantiates `?0` with `(W, W)` and then +// proves `W: Trait` and `W: Trait`, resulting in a coinductive cycle. +// +// Proving coinductive cycles runs until we reach a fixpoint. This fixpoint is +// never reached here and each step doubles the amount of nested obligations. +// +// This previously caused a hang in the trait solver, see +// https://github.com/rust-lang/trait-system-refactor-initiative/issues/13. + +#![feature(rustc_attrs)] + +#[rustc_coinductive] +trait Trait {} + +struct W(T); + +impl Trait for W<(W, W)> +where + W: Trait, + W: Trait, +{ +} + +fn impls() {} + +fn main() { + impls::>(); + //~^ ERROR type annotations needed + //~| ERROR overflow evaluating the requirement +} diff --git a/tests/ui/traits/new-solver/coinduction/fixpoint-exponential-growth.stderr b/tests/ui/traits/new-solver/coinduction/fixpoint-exponential-growth.stderr new file mode 100644 index 000000000000..7d3535e1f01e --- /dev/null +++ b/tests/ui/traits/new-solver/coinduction/fixpoint-exponential-growth.stderr @@ -0,0 +1,23 @@ +error[E0282]: type annotations needed + --> $DIR/fixpoint-exponential-growth.rs:29:5 + | +LL | impls::>(); + | ^^^^^^^^^^^^^ cannot infer type of the type parameter `T` declared on the function `impls` + +error[E0275]: overflow evaluating the requirement `W<_>: Trait` + --> $DIR/fixpoint-exponential-growth.rs:29:5 + | +LL | impls::>(); + | ^^^^^^^^^^^^^ + | + = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`fixpoint_exponential_growth`) +note: required by a bound in `impls` + --> $DIR/fixpoint-exponential-growth.rs:26:13 + | +LL | fn impls() {} + | ^^^^^ required by this bound in `impls` + +error: aborting due to 2 previous errors + +Some errors have detailed explanations: E0275, E0282. +For more information about an error, try `rustc --explain E0275`. diff --git a/tests/ui/traits/new-solver/coinduction/incompleteness-unstable-result.rs b/tests/ui/traits/new-solver/coinduction/incompleteness-unstable-result.rs new file mode 100644 index 000000000000..0cd14f05c8d9 --- /dev/null +++ b/tests/ui/traits/new-solver/coinduction/incompleteness-unstable-result.rs @@ -0,0 +1,69 @@ +// compile-flags: -Ztrait-solver=next +#![feature(rustc_attrs)] + +// This test is incredibly subtle. At its core the goal is to get a coinductive cycle, +// which, depending on its root goal, either holds or errors. We achieve this by getting +// incomplete inference via a `ParamEnv` candidate in the `A` impl and required +// inference from an `Impl` candidate in the `B` impl. +// +// To make global cache accesses stronger than the guidance from the where-bounds, we add +// another coinductive cycle from `A: Trait` to `A: Trait` and only +// constrain `D` directly. This means that any candidates which rely on `V` only make +// progress in the second iteration, allowing a cache access in the first iteration to take +// precedence. +// +// tl;dr: our caching of coinductive cycles was broken and this is a regression +// test for that. + +#[rustc_coinductive] +trait Trait {} +struct A(*const T); +struct B(*const T); + +trait IncompleteGuidance {} +impl IncompleteGuidance for T {} +impl IncompleteGuidance for T {} +impl IncompleteGuidance for T {} + +trait ImplGuidance {} +impl ImplGuidance for T {} +impl ImplGuidance for T {} + +impl Trait for A +where + T: IncompleteGuidance, + A: Trait, + B: Trait, + (): ToU8, +{ +} + +trait ToU8 {} +impl ToU8 for () {} + +impl Trait for B +where + T: ImplGuidance, + A: Trait, +{ +} + +fn impls_trait, U: ?Sized, V: ?Sized, D: ?Sized>() {} + +fn with_bound() +where + X: IncompleteGuidance, + X: IncompleteGuidance, + X: IncompleteGuidance, +{ + impls_trait::, _, _, _>(); // entering the cycle from `B` works + + // entering the cycle from `A` fails, but would work if we were to use the cache + // result of `B`. + impls_trait::, _, _, _>(); + //~^ ERROR the trait bound `A: Trait<_, _, _>` is not satisfied +} + +fn main() { + with_bound::(); +} diff --git a/tests/ui/traits/new-solver/coinduction/incompleteness-unstable-result.stderr b/tests/ui/traits/new-solver/coinduction/incompleteness-unstable-result.stderr new file mode 100644 index 000000000000..f1871ff0564a --- /dev/null +++ b/tests/ui/traits/new-solver/coinduction/incompleteness-unstable-result.stderr @@ -0,0 +1,16 @@ +error[E0277]: the trait bound `A: Trait<_, _, _>` is not satisfied + --> $DIR/incompleteness-unstable-result.rs:63:19 + | +LL | impls_trait::, _, _, _>(); + | ^^^^ the trait `Trait<_, _, _>` is not implemented for `A` + | + = help: the trait `Trait` is implemented for `A` +note: required by a bound in `impls_trait` + --> $DIR/incompleteness-unstable-result.rs:51:28 + | +LL | fn impls_trait, U: ?Sized, V: ?Sized, D: ?Sized>() {} + | ^^^^^^^^^^^^^^ required by this bound in `impls_trait` + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0277`. diff --git a/tests/ui/traits/new-solver/overflow/global-cache.rs b/tests/ui/traits/new-solver/overflow/global-cache.rs new file mode 100644 index 000000000000..adc03da04a85 --- /dev/null +++ b/tests/ui/traits/new-solver/overflow/global-cache.rs @@ -0,0 +1,23 @@ +// compile-flags: -Ztrait-solver=next + +// Check that we consider the reached depth of global cache +// entries when detecting overflow. We would otherwise be unstable +// wrt to incremental compilation. +#![recursion_limit = "9"] + +trait Trait {} + +struct Inc(T); + +impl Trait for Inc {} +impl Trait for () {} + +fn impls_trait() {} + +type Four = Inc>>>; + +fn main() { + impls_trait::>>(); + impls_trait::>>>>(); + //~^ ERROR overflow evaluating the requirement +} diff --git a/tests/ui/traits/new-solver/overflow/global-cache.stderr b/tests/ui/traits/new-solver/overflow/global-cache.stderr new file mode 100644 index 000000000000..f3b86a083ad9 --- /dev/null +++ b/tests/ui/traits/new-solver/overflow/global-cache.stderr @@ -0,0 +1,16 @@ +error[E0275]: overflow evaluating the requirement `Inc>>>>>>: Trait` + --> $DIR/global-cache.rs:21:5 + | +LL | impls_trait::>>>>(); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = help: consider increasing the recursion limit by adding a `#![recursion_limit = "18"]` attribute to your crate (`global_cache`) +note: required by a bound in `impls_trait` + --> $DIR/global-cache.rs:15:19 + | +LL | fn impls_trait() {} + | ^^^^^ required by this bound in `impls_trait` + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0275`.