diff --git a/compiler/rustc_infer/src/traits/mod.rs b/compiler/rustc_infer/src/traits/mod.rs index 72ec07375ac0e..4808a1defdd8f 100644 --- a/compiler/rustc_infer/src/traits/mod.rs +++ b/compiler/rustc_infer/src/traits/mod.rs @@ -135,16 +135,18 @@ pub struct FulfillmentError<'tcx> { #[derive(Clone)] pub enum FulfillmentErrorCode<'tcx> { - /// Inherently impossible to fulfill; this trait is implemented if and only if it is already implemented. + /// Inherently impossible to fulfill; this trait is implemented if and only + /// if it is already implemented. Cycle(Vec>), SelectionError(SelectionError<'tcx>), ProjectionError(MismatchedProjectionTypes<'tcx>), SubtypeError(ExpectedFound>, TypeError<'tcx>), // always comes from a SubtypePredicate ConstEquateError(ExpectedFound>, TypeError<'tcx>), Ambiguity { - /// Overflow reported from the new solver `-Znext-solver`, which will - /// be reported as an regular error as opposed to a fatal error. - overflow: bool, + /// Overflow is only `Some(suggest_recursion_limit)` when using the next generation + /// trait solver `-Znext-solver`. With the old solver overflow is eagerly handled by + /// emitting a fatal error instead. + overflow: Option, }, } diff --git a/compiler/rustc_infer/src/traits/structural_impls.rs b/compiler/rustc_infer/src/traits/structural_impls.rs index 3b4050fcd27ef..bf4f88530d04e 100644 --- a/compiler/rustc_infer/src/traits/structural_impls.rs +++ b/compiler/rustc_infer/src/traits/structural_impls.rs @@ -47,8 +47,10 @@ impl<'tcx> fmt::Debug for traits::FulfillmentErrorCode<'tcx> { ConstEquateError(ref a, ref b) => { write!(f, "CodeConstEquateError({a:?}, {b:?})") } - Ambiguity { overflow: false } => write!(f, "Ambiguity"), - Ambiguity { overflow: true } => write!(f, "Overflow"), + Ambiguity { overflow: None } => write!(f, "Ambiguity"), + Ambiguity { overflow: Some(suggest_increasing_limit) } => { + write!(f, "Overflow({suggest_increasing_limit})") + } Cycle(ref cycle) => write!(f, "Cycle({cycle:?})"), } } diff --git a/compiler/rustc_middle/src/traits/solve.rs b/compiler/rustc_middle/src/traits/solve.rs index 048df367bd65c..0dc6512601121 100644 --- a/compiler/rustc_middle/src/traits/solve.rs +++ b/compiler/rustc_middle/src/traits/solve.rs @@ -60,7 +60,6 @@ pub enum Certainty { impl Certainty { pub const AMBIGUOUS: Certainty = Certainty::Maybe(MaybeCause::Ambiguity); - pub const OVERFLOW: Certainty = Certainty::Maybe(MaybeCause::Overflow); /// Use this function to merge the certainty of multiple nested subgoals. /// @@ -79,16 +78,13 @@ impl Certainty { (Certainty::Yes, Certainty::Yes) => Certainty::Yes, (Certainty::Yes, Certainty::Maybe(_)) => other, (Certainty::Maybe(_), Certainty::Yes) => self, - (Certainty::Maybe(MaybeCause::Ambiguity), Certainty::Maybe(MaybeCause::Ambiguity)) => { - Certainty::Maybe(MaybeCause::Ambiguity) - } - (Certainty::Maybe(MaybeCause::Ambiguity), Certainty::Maybe(MaybeCause::Overflow)) - | (Certainty::Maybe(MaybeCause::Overflow), Certainty::Maybe(MaybeCause::Ambiguity)) - | (Certainty::Maybe(MaybeCause::Overflow), Certainty::Maybe(MaybeCause::Overflow)) => { - Certainty::Maybe(MaybeCause::Overflow) - } + (Certainty::Maybe(a), Certainty::Maybe(b)) => Certainty::Maybe(a.unify_with(b)), } } + + pub const fn overflow(suggest_increasing_limit: bool) -> Certainty { + Certainty::Maybe(MaybeCause::Overflow { suggest_increasing_limit }) + } } /// Why we failed to evaluate a goal. @@ -99,7 +95,21 @@ pub enum MaybeCause { /// or we hit a case where we just don't bother, e.g. `?x: Trait` goals. Ambiguity, /// We gave up due to an overflow, most often by hitting the recursion limit. - Overflow, + Overflow { suggest_increasing_limit: bool }, +} + +impl MaybeCause { + fn unify_with(self, other: MaybeCause) -> MaybeCause { + match (self, other) { + (MaybeCause::Ambiguity, MaybeCause::Ambiguity) => MaybeCause::Ambiguity, + (MaybeCause::Ambiguity, MaybeCause::Overflow { .. }) => other, + (MaybeCause::Overflow { .. }, MaybeCause::Ambiguity) => self, + ( + MaybeCause::Overflow { suggest_increasing_limit: a }, + MaybeCause::Overflow { suggest_increasing_limit: b }, + ) => MaybeCause::Overflow { suggest_increasing_limit: a || b }, + } + } } #[derive(Debug, PartialEq, Eq, Clone, Copy, Hash, HashStable, TypeFoldable, TypeVisitable)] diff --git a/compiler/rustc_trait_selection/src/solve/alias_relate.rs b/compiler/rustc_trait_selection/src/solve/alias_relate.rs index afd9d95cb570e..67657c81cf602 100644 --- a/compiler/rustc_trait_selection/src/solve/alias_relate.rs +++ b/compiler/rustc_trait_selection/src/solve/alias_relate.rs @@ -36,11 +36,13 @@ impl<'tcx> EvalCtxt<'_, 'tcx> { let Goal { param_env, predicate: (lhs, rhs, direction) } = goal; let Some(lhs) = self.try_normalize_term(param_env, lhs)? else { - return self.evaluate_added_goals_and_make_canonical_response(Certainty::OVERFLOW); + return self + .evaluate_added_goals_and_make_canonical_response(Certainty::overflow(true)); }; let Some(rhs) = self.try_normalize_term(param_env, rhs)? else { - return self.evaluate_added_goals_and_make_canonical_response(Certainty::OVERFLOW); + return self + .evaluate_added_goals_and_make_canonical_response(Certainty::overflow(true)); }; let variance = match direction { diff --git a/compiler/rustc_trait_selection/src/solve/eval_ctxt/mod.rs b/compiler/rustc_trait_selection/src/solve/eval_ctxt/mod.rs index ed428bb8e6629..e20cec1879033 100644 --- a/compiler/rustc_trait_selection/src/solve/eval_ctxt/mod.rs +++ b/compiler/rustc_trait_selection/src/solve/eval_ctxt/mod.rs @@ -7,6 +7,7 @@ use rustc_infer::infer::{ BoundRegionConversionTime, DefineOpaqueTypes, InferCtxt, InferOk, TyCtxtInferExt, }; use rustc_infer::traits::query::NoSolution; +use rustc_infer::traits::solve::MaybeCause; use rustc_infer::traits::ObligationCause; use rustc_middle::infer::canonical::CanonicalVarInfos; use rustc_middle::infer::unify_key::{ConstVariableOrigin, ConstVariableOriginKind}; @@ -29,7 +30,7 @@ use std::ops::ControlFlow; use crate::traits::vtable::{count_own_vtable_entries, prepare_vtable_segments, VtblSegment}; use super::inspect::ProofTreeBuilder; -use super::{search_graph, GoalEvaluationKind}; +use super::{search_graph, GoalEvaluationKind, FIXPOINT_STEP_LIMIT}; use super::{search_graph::SearchGraph, Goal}; use super::{GoalSource, SolverMode}; pub use select::InferCtxtSelectExt; @@ -154,10 +155,6 @@ impl<'a, 'tcx> EvalCtxt<'a, 'tcx> { self.search_graph.solver_mode() } - pub(super) fn local_overflow_limit(&self) -> usize { - self.search_graph.local_overflow_limit() - } - /// Creates a root evaluation context and search graph. This should only be /// used from outside of any evaluation, and other methods should be preferred /// over using this manually (such as [`InferCtxtEvalExt::evaluate_root_goal`]). @@ -167,7 +164,7 @@ impl<'a, 'tcx> EvalCtxt<'a, 'tcx> { f: impl FnOnce(&mut EvalCtxt<'_, 'tcx>) -> R, ) -> (R, Option>) { let mode = if infcx.intercrate { SolverMode::Coherence } else { SolverMode::Normal }; - let mut search_graph = search_graph::SearchGraph::new(infcx.tcx, mode); + let mut search_graph = search_graph::SearchGraph::new(mode); let mut ecx = EvalCtxt { search_graph: &mut search_graph, @@ -388,16 +385,18 @@ impl<'a, 'tcx> EvalCtxt<'a, 'tcx> { && source != GoalSource::ImplWhereBound }; - if response.value.certainty == Certainty::OVERFLOW && !keep_overflow_constraints() { - (Certainty::OVERFLOW, false) - } else { - let has_changed = !response.value.var_values.is_identity_modulo_regions() - || !response.value.external_constraints.opaque_types.is_empty(); - - let certainty = - self.instantiate_and_apply_query_response(param_env, original_values, response); - (certainty, has_changed) + if let Certainty::Maybe(MaybeCause::Overflow { .. }) = response.value.certainty + && !keep_overflow_constraints() + { + return (response.value.certainty, false); } + + let has_changed = !response.value.var_values.is_identity_modulo_regions() + || !response.value.external_constraints.opaque_types.is_empty(); + + let certainty = + self.instantiate_and_apply_query_response(param_env, original_values, response); + (certainty, has_changed) } fn compute_goal(&mut self, goal: Goal<'tcx, ty::Predicate<'tcx>>) -> QueryResult<'tcx> { @@ -466,8 +465,8 @@ impl<'a, 'tcx> EvalCtxt<'a, 'tcx> { let inspect = self.inspect.new_evaluate_added_goals(); let inspect = core::mem::replace(&mut self.inspect, inspect); - let mut response = Ok(Certainty::OVERFLOW); - for _ in 0..self.local_overflow_limit() { + let mut response = Ok(Certainty::overflow(false)); + for _ in 0..FIXPOINT_STEP_LIMIT { // FIXME: This match is a bit ugly, it might be nice to change the inspect // stuff to use a closure instead. which should hopefully simplify this a bit. match self.evaluate_added_goals_step() { diff --git a/compiler/rustc_trait_selection/src/solve/fulfill.rs b/compiler/rustc_trait_selection/src/solve/fulfill.rs index c1b07765e5011..bc2bae9da6131 100644 --- a/compiler/rustc_trait_selection/src/solve/fulfill.rs +++ b/compiler/rustc_trait_selection/src/solve/fulfill.rs @@ -24,7 +24,7 @@ use super::{Certainty, InferCtxtEvalExt}; /// It is also likely that we want to use slightly different datastructures /// here as this will have to deal with far more root goals than `evaluate_all`. pub struct FulfillmentCtxt<'tcx> { - obligations: Vec>, + obligations: ObligationStorage<'tcx>, /// The snapshot in which this context was created. Using the context /// outside of this snapshot leads to subtle bugs if the snapshot @@ -33,6 +33,57 @@ pub struct FulfillmentCtxt<'tcx> { usable_in_snapshot: usize, } +#[derive(Default)] +struct ObligationStorage<'tcx> { + /// Obligations which resulted in an overflow in fulfillment itself. + /// + /// We cannot eagerly return these as error so we instead store them here + /// to avoid recomputing them each time `select_where_possible` is called. + /// This also allows us to return the correct `FulfillmentError` for them. + overflowed: Vec>, + pending: Vec>, +} + +impl<'tcx> ObligationStorage<'tcx> { + fn register(&mut self, obligation: PredicateObligation<'tcx>) { + self.pending.push(obligation); + } + + fn clone_pending(&self) -> Vec> { + let mut obligations = self.pending.clone(); + obligations.extend(self.overflowed.iter().cloned()); + obligations + } + + fn take_pending(&mut self) -> Vec> { + let mut obligations = mem::take(&mut self.pending); + obligations.extend(self.overflowed.drain(..)); + obligations + } + + fn unstalled_for_select(&mut self) -> impl Iterator> { + mem::take(&mut self.pending).into_iter() + } + + fn on_fulfillment_overflow(&mut self, infcx: &InferCtxt<'tcx>) { + infcx.probe(|_| { + // IMPORTANT: we must not use solve any inference variables in the obligations + // as this is all happening inside of a probe. We use a probe to make sure + // we get all obligations involved in the overflow. We pretty much check: if + // we were to do another step of `select_where_possible`, which goals would + // change. + self.overflowed.extend(self.pending.extract_if(|o| { + let goal = o.clone().into(); + let result = infcx.evaluate_root_goal(goal, GenerateProofTree::Never).0; + match result { + Ok((has_changed, _)) => has_changed, + _ => false, + } + })); + }) + } +} + impl<'tcx> FulfillmentCtxt<'tcx> { pub fn new(infcx: &InferCtxt<'tcx>) -> FulfillmentCtxt<'tcx> { assert!( @@ -40,7 +91,10 @@ impl<'tcx> FulfillmentCtxt<'tcx> { "new trait solver fulfillment context created when \ infcx is set up for old trait solver" ); - FulfillmentCtxt { obligations: Vec::new(), usable_in_snapshot: infcx.num_open_snapshots() } + FulfillmentCtxt { + obligations: Default::default(), + usable_in_snapshot: infcx.num_open_snapshots(), + } } fn inspect_evaluated_obligation( @@ -67,40 +121,24 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentCtxt<'tcx> { obligation: PredicateObligation<'tcx>, ) { assert_eq!(self.usable_in_snapshot, infcx.num_open_snapshots()); - self.obligations.push(obligation); + self.obligations.register(obligation); } fn collect_remaining_errors(&mut self, infcx: &InferCtxt<'tcx>) -> Vec> { - self.obligations + let mut errors: Vec<_> = self + .obligations + .pending .drain(..) - .map(|obligation| { - let code = infcx.probe(|_| { - match infcx - .evaluate_root_goal(obligation.clone().into(), GenerateProofTree::IfEnabled) - .0 - { - Ok((_, Certainty::Maybe(MaybeCause::Ambiguity))) => { - FulfillmentErrorCode::Ambiguity { overflow: false } - } - Ok((_, Certainty::Maybe(MaybeCause::Overflow))) => { - FulfillmentErrorCode::Ambiguity { overflow: true } - } - Ok((_, Certainty::Yes)) => { - bug!("did not expect successful goal when collecting ambiguity errors") - } - Err(_) => { - bug!("did not expect selection error when collecting ambiguity errors") - } - } - }); + .map(|obligation| fulfillment_error_for_stalled(infcx, obligation)) + .collect(); - FulfillmentError { - obligation: obligation.clone(), - code, - root_obligation: obligation, - } - }) - .collect() + errors.extend(self.obligations.overflowed.drain(..).map(|obligation| FulfillmentError { + root_obligation: obligation.clone(), + code: FulfillmentErrorCode::Ambiguity { overflow: Some(true) }, + obligation, + })); + + errors } fn select_where_possible(&mut self, infcx: &InferCtxt<'tcx>) -> Vec> { @@ -108,79 +146,27 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentCtxt<'tcx> { let mut errors = Vec::new(); for i in 0.. { if !infcx.tcx.recursion_limit().value_within_limit(i) { - // Only return true errors that we have accumulated while processing; - // keep ambiguities around, *including overflows*, because they shouldn't - // be considered true errors. + self.obligations.on_fulfillment_overflow(infcx); + // Only return true errors that we have accumulated while processing. return errors; } let mut has_changed = false; - for obligation in mem::take(&mut self.obligations) { + for obligation in self.obligations.unstalled_for_select() { let goal = obligation.clone().into(); let result = infcx.evaluate_root_goal(goal, GenerateProofTree::IfEnabled).0; self.inspect_evaluated_obligation(infcx, &obligation, &result); let (changed, certainty) = match result { Ok(result) => result, Err(NoSolution) => { - errors.push(FulfillmentError { - obligation: obligation.clone(), - code: match goal.predicate.kind().skip_binder() { - ty::PredicateKind::Clause(ty::ClauseKind::Projection(_)) => { - FulfillmentErrorCode::ProjectionError( - // FIXME: This could be a `Sorts` if the term is a type - MismatchedProjectionTypes { err: TypeError::Mismatch }, - ) - } - ty::PredicateKind::NormalizesTo(..) => { - FulfillmentErrorCode::ProjectionError( - MismatchedProjectionTypes { err: TypeError::Mismatch }, - ) - } - ty::PredicateKind::AliasRelate(_, _, _) => { - FulfillmentErrorCode::ProjectionError( - MismatchedProjectionTypes { err: TypeError::Mismatch }, - ) - } - ty::PredicateKind::Subtype(pred) => { - let (a, b) = infcx.enter_forall_and_leak_universe( - goal.predicate.kind().rebind((pred.a, pred.b)), - ); - let expected_found = ExpectedFound::new(true, a, b); - FulfillmentErrorCode::SubtypeError( - expected_found, - TypeError::Sorts(expected_found), - ) - } - ty::PredicateKind::Coerce(pred) => { - let (a, b) = infcx.enter_forall_and_leak_universe( - goal.predicate.kind().rebind((pred.a, pred.b)), - ); - let expected_found = ExpectedFound::new(false, a, b); - FulfillmentErrorCode::SubtypeError( - expected_found, - TypeError::Sorts(expected_found), - ) - } - ty::PredicateKind::Clause(_) - | ty::PredicateKind::ObjectSafe(_) - | ty::PredicateKind::Ambiguous => { - FulfillmentErrorCode::SelectionError( - SelectionError::Unimplemented, - ) - } - ty::PredicateKind::ConstEquate(..) => { - bug!("unexpected goal: {goal:?}") - } - }, - root_obligation: obligation, - }); + errors.push(fulfillment_error_for_no_solution(infcx, obligation)); continue; } }; has_changed |= changed; match certainty { Certainty::Yes => {} - Certainty::Maybe(_) => self.obligations.push(obligation), + Certainty::Maybe(_) => self.obligations.register(obligation), } } @@ -193,13 +179,84 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentCtxt<'tcx> { } fn pending_obligations(&self) -> Vec> { - self.obligations.clone() + self.obligations.clone_pending() } fn drain_unstalled_obligations( &mut self, _: &InferCtxt<'tcx>, ) -> Vec> { - std::mem::take(&mut self.obligations) + self.obligations.take_pending() } } + +fn fulfillment_error_for_no_solution<'tcx>( + infcx: &InferCtxt<'tcx>, + obligation: PredicateObligation<'tcx>, +) -> FulfillmentError<'tcx> { + let code = match obligation.predicate.kind().skip_binder() { + ty::PredicateKind::Clause(ty::ClauseKind::Projection(_)) => { + FulfillmentErrorCode::ProjectionError( + // FIXME: This could be a `Sorts` if the term is a type + MismatchedProjectionTypes { err: TypeError::Mismatch }, + ) + } + ty::PredicateKind::NormalizesTo(..) => { + FulfillmentErrorCode::ProjectionError(MismatchedProjectionTypes { + err: TypeError::Mismatch, + }) + } + ty::PredicateKind::AliasRelate(_, _, _) => { + FulfillmentErrorCode::ProjectionError(MismatchedProjectionTypes { + err: TypeError::Mismatch, + }) + } + ty::PredicateKind::Subtype(pred) => { + let (a, b) = infcx.enter_forall_and_leak_universe( + obligation.predicate.kind().rebind((pred.a, pred.b)), + ); + let expected_found = ExpectedFound::new(true, a, b); + FulfillmentErrorCode::SubtypeError(expected_found, TypeError::Sorts(expected_found)) + } + ty::PredicateKind::Coerce(pred) => { + let (a, b) = infcx.enter_forall_and_leak_universe( + obligation.predicate.kind().rebind((pred.a, pred.b)), + ); + let expected_found = ExpectedFound::new(false, a, b); + FulfillmentErrorCode::SubtypeError(expected_found, TypeError::Sorts(expected_found)) + } + ty::PredicateKind::Clause(_) + | ty::PredicateKind::ObjectSafe(_) + | ty::PredicateKind::Ambiguous => { + FulfillmentErrorCode::SelectionError(SelectionError::Unimplemented) + } + ty::PredicateKind::ConstEquate(..) => { + bug!("unexpected goal: {obligation:?}") + } + }; + FulfillmentError { root_obligation: obligation.clone(), code, obligation } +} + +fn fulfillment_error_for_stalled<'tcx>( + infcx: &InferCtxt<'tcx>, + obligation: PredicateObligation<'tcx>, +) -> FulfillmentError<'tcx> { + let code = infcx.probe(|_| { + match infcx.evaluate_root_goal(obligation.clone().into(), GenerateProofTree::Never).0 { + Ok((_, Certainty::Maybe(MaybeCause::Ambiguity))) => { + FulfillmentErrorCode::Ambiguity { overflow: None } + } + Ok((_, Certainty::Maybe(MaybeCause::Overflow { suggest_increasing_limit }))) => { + FulfillmentErrorCode::Ambiguity { overflow: Some(suggest_increasing_limit) } + } + Ok((_, Certainty::Yes)) => { + bug!("did not expect successful goal when collecting ambiguity errors") + } + Err(_) => { + bug!("did not expect selection error when collecting ambiguity errors") + } + } + }); + + FulfillmentError { obligation: obligation.clone(), code, root_obligation: obligation } +} diff --git a/compiler/rustc_trait_selection/src/solve/mod.rs b/compiler/rustc_trait_selection/src/solve/mod.rs index 51094b781c0cf..0bf28f520a4d2 100644 --- a/compiler/rustc_trait_selection/src/solve/mod.rs +++ b/compiler/rustc_trait_selection/src/solve/mod.rs @@ -42,6 +42,17 @@ pub use fulfill::FulfillmentCtxt; pub(crate) use normalize::deeply_normalize_for_diagnostics; pub use normalize::{deeply_normalize, deeply_normalize_with_skipped_universes}; +/// How many fixpoint iterations we should attempt inside of the solver before bailing +/// with overflow. +/// +/// We previously used `tcx.recursion_limit().0.checked_ilog2().unwrap_or(0)` for this. +/// However, it feels unlikely that uncreasing the recursion limit by a power of two +/// to get one more itereation is every useful or desirable. We now instead used a constant +/// here. If there ever ends up some use-cases where a bigger number of fixpoint iterations +/// is required, we can add a new attribute for that or revert this to be dependant on the +/// recursion limit again. However, this feels very unlikely. +const FIXPOINT_STEP_LIMIT: usize = 8; + #[derive(Debug, Clone, Copy)] enum SolverMode { /// Ordinary trait solving, using everywhere except for coherence. diff --git a/compiler/rustc_trait_selection/src/solve/search_graph.rs b/compiler/rustc_trait_selection/src/solve/search_graph.rs index bede94a2e43d6..07a8aca85a011 100644 --- a/compiler/rustc_trait_selection/src/solve/search_graph.rs +++ b/compiler/rustc_trait_selection/src/solve/search_graph.rs @@ -1,3 +1,5 @@ +use crate::solve::FIXPOINT_STEP_LIMIT; + use super::inspect; use super::inspect::ProofTreeBuilder; use super::SolverMode; @@ -99,7 +101,6 @@ impl<'tcx> ProvisionalCacheEntry<'tcx> { pub(super) struct SearchGraph<'tcx> { mode: SolverMode, - local_overflow_limit: usize, /// The stack of goals currently being computed. /// /// An element is *deeper* in the stack if its index is *lower*. @@ -116,10 +117,9 @@ pub(super) struct SearchGraph<'tcx> { } impl<'tcx> SearchGraph<'tcx> { - pub(super) fn new(tcx: TyCtxt<'tcx>, mode: SolverMode) -> SearchGraph<'tcx> { + pub(super) fn new(mode: SolverMode) -> SearchGraph<'tcx> { Self { mode, - local_overflow_limit: tcx.recursion_limit().0.checked_ilog2().unwrap_or(0) as usize, stack: Default::default(), provisional_cache: Default::default(), cycle_participants: Default::default(), @@ -130,10 +130,6 @@ impl<'tcx> SearchGraph<'tcx> { self.mode } - pub(super) fn local_overflow_limit(&self) -> usize { - self.local_overflow_limit - } - /// Update the stack and reached depths on cache hits. #[instrument(level = "debug", skip(self))] fn on_cache_hit(&mut self, additional_depth: usize, encountered_overflow: bool) { @@ -277,7 +273,7 @@ impl<'tcx> SearchGraph<'tcx> { } inspect.goal_evaluation_kind(inspect::WipCanonicalGoalEvaluationKind::Overflow); - return Self::response_no_constraints(tcx, input, Certainty::OVERFLOW); + return Self::response_no_constraints(tcx, input, Certainty::overflow(true)); }; // Try to fetch the goal from the global cache. @@ -370,7 +366,7 @@ impl<'tcx> SearchGraph<'tcx> { } else if is_coinductive_cycle { Self::response_no_constraints(tcx, input, Certainty::Yes) } else { - Self::response_no_constraints(tcx, input, Certainty::OVERFLOW) + Self::response_no_constraints(tcx, input, Certainty::overflow(false)) }; } else { // No entry, we push this goal on the stack and try to prove it. @@ -398,7 +394,7 @@ impl<'tcx> SearchGraph<'tcx> { // of this we continuously recompute the cycle until the result // of the previous iteration is equal to the final result, at which // point we are done. - for _ in 0..self.local_overflow_limit() { + for _ in 0..FIXPOINT_STEP_LIMIT { let result = prove_goal(self, inspect); let stack_entry = self.pop_stack(); debug_assert_eq!(stack_entry.input, input); @@ -431,7 +427,8 @@ impl<'tcx> SearchGraph<'tcx> { } else if stack_entry.has_been_used == HasBeenUsed::COINDUCTIVE_CYCLE { Self::response_no_constraints(tcx, input, Certainty::Yes) == result } else if stack_entry.has_been_used == HasBeenUsed::INDUCTIVE_CYCLE { - Self::response_no_constraints(tcx, input, Certainty::OVERFLOW) == result + Self::response_no_constraints(tcx, input, Certainty::overflow(false)) + == result } else { false }; @@ -452,7 +449,7 @@ impl<'tcx> SearchGraph<'tcx> { debug!("canonical cycle overflow"); let current_entry = self.pop_stack(); debug_assert!(current_entry.has_been_used.is_empty()); - let result = Self::response_no_constraints(tcx, input, Certainty::OVERFLOW); + let result = Self::response_no_constraints(tcx, input, Certainty::overflow(false)); (current_entry, result) }); diff --git a/compiler/rustc_trait_selection/src/traits/coherence.rs b/compiler/rustc_trait_selection/src/traits/coherence.rs index 6778cb7b7a98f..68111c4cc1fdc 100644 --- a/compiler/rustc_trait_selection/src/traits/coherence.rs +++ b/compiler/rustc_trait_selection/src/traits/coherence.rs @@ -22,7 +22,7 @@ use rustc_errors::{Diag, EmissionGuarantee}; use rustc_hir::def::DefKind; use rustc_hir::def_id::{DefId, LOCAL_CRATE}; use rustc_infer::infer::{DefineOpaqueTypes, InferCtxt, TyCtxtInferExt}; -use rustc_infer::traits::{util, TraitEngine, TraitEngineExt}; +use rustc_infer::traits::{util, FulfillmentErrorCode, TraitEngine, TraitEngineExt}; use rustc_middle::traits::query::NoSolution; use rustc_middle::traits::solve::{CandidateSource, Certainty, Goal}; use rustc_middle::traits::specialization_graph::OverlapMode; @@ -35,6 +35,8 @@ use rustc_span::DUMMY_SP; use std::fmt::Debug; use std::ops::ControlFlow; +use super::error_reporting::suggest_new_overflow_limit; + /// Whether we do the orphan check relative to this crate or /// to some remote crate. #[derive(Copy, Clone, Debug)] @@ -56,6 +58,9 @@ pub struct OverlapResult<'tcx> { /// `true` if the overlap might've been permitted before the shift /// to universes. pub involves_placeholder: bool, + + /// Used in the new solver to suggest increasing the recursion limit. + pub overflowing_predicates: Vec>, } pub fn add_placeholder_note(err: &mut Diag<'_, G>) { @@ -65,6 +70,18 @@ pub fn add_placeholder_note(err: &mut Diag<'_, G>) { ); } +pub fn suggest_increasing_recursion_limit<'tcx, G: EmissionGuarantee>( + tcx: TyCtxt<'tcx>, + err: &mut Diag<'_, G>, + overflowing_predicates: &[ty::Predicate<'tcx>], +) { + for pred in overflowing_predicates { + err.note(format!("overflow evaluating the requirement `{}`", pred)); + } + + suggest_new_overflow_limit(tcx, err); +} + #[derive(Debug, Clone, Copy)] enum TrackAmbiguityCauses { Yes, @@ -221,11 +238,13 @@ fn overlap<'tcx>( ), ); + let mut overflowing_predicates = Vec::new(); if overlap_mode.use_implicit_negative() { - if let Some(_failing_obligation) = - impl_intersection_has_impossible_obligation(selcx, &obligations) - { - return None; + match impl_intersection_has_impossible_obligation(selcx, &obligations) { + IntersectionHasImpossibleObligations::Yes => return None, + IntersectionHasImpossibleObligations::No { overflowing_predicates: p } => { + overflowing_predicates = p + } } } @@ -261,7 +280,12 @@ fn overlap<'tcx>( impl_header = deeply_normalize_for_diagnostics(&infcx, param_env, impl_header); } - Some(OverlapResult { impl_header, intercrate_ambiguity_causes, involves_placeholder }) + Some(OverlapResult { + impl_header, + intercrate_ambiguity_causes, + involves_placeholder, + overflowing_predicates, + }) } #[instrument(level = "debug", skip(infcx), ret)] @@ -287,6 +311,19 @@ fn equate_impl_headers<'tcx>( result.map(|infer_ok| infer_ok.obligations).ok() } +/// The result of [fn impl_intersection_has_impossible_obligation]. +enum IntersectionHasImpossibleObligations<'tcx> { + Yes, + No { + /// With `-Znext-solver=coherence`, some obligations may + /// fail if only the user increased the recursion limit. + /// + /// We return those obligations here and mention them in the + /// error message. + overflowing_predicates: Vec>, + }, +} + /// Check if both impls can be satisfied by a common type by considering whether /// any of either impl's obligations is not known to hold. /// @@ -308,7 +345,7 @@ fn equate_impl_headers<'tcx>( fn impl_intersection_has_impossible_obligation<'a, 'cx, 'tcx>( selcx: &mut SelectionContext<'cx, 'tcx>, obligations: &'a [PredicateObligation<'tcx>], -) -> Option> { +) -> IntersectionHasImpossibleObligations<'tcx> { let infcx = selcx.infcx; if infcx.next_trait_solver() { @@ -317,28 +354,42 @@ fn impl_intersection_has_impossible_obligation<'a, 'cx, 'tcx>( // We only care about the obligations that are *definitely* true errors. // Ambiguities do not prove the disjointness of two impls. - let mut errors = fulfill_cx.select_where_possible(infcx); - errors.pop().map(|err| err.obligation) + let errors = fulfill_cx.select_where_possible(infcx); + if errors.is_empty() { + let overflow_errors = fulfill_cx.collect_remaining_errors(infcx); + let overflowing_predicates = overflow_errors + .into_iter() + .filter(|e| match e.code { + FulfillmentErrorCode::Ambiguity { overflow: Some(true) } => true, + _ => false, + }) + .map(|e| infcx.resolve_vars_if_possible(e.obligation.predicate)) + .collect(); + IntersectionHasImpossibleObligations::No { overflowing_predicates } + } else { + IntersectionHasImpossibleObligations::Yes + } } else { - obligations - .iter() - .find(|obligation| { - // We use `evaluate_root_obligation` to correctly track intercrate - // ambiguity clauses. We cannot use this in the new solver. - let evaluation_result = selcx.evaluate_root_obligation(obligation); - - match evaluation_result { - Ok(result) => !result.may_apply(), - // If overflow occurs, we need to conservatively treat the goal as possibly holding, - // since there can be instantiations of this goal that don't overflow and result in - // success. This isn't much of a problem in the old solver, since we treat overflow - // fatally (this still can be encountered: ), - // but in the new solver, this is very important for correctness, since overflow - // *must* be treated as ambiguity for completeness. - Err(_overflow) => false, + for obligation in obligations { + // We use `evaluate_root_obligation` to correctly track intercrate + // ambiguity clauses. + let evaluation_result = selcx.evaluate_root_obligation(obligation); + + match evaluation_result { + Ok(result) => { + if !result.may_apply() { + return IntersectionHasImpossibleObligations::Yes; + } } - }) - .cloned() + // If overflow occurs, we need to conservatively treat the goal as possibly holding, + // since there can be instantiations of this goal that don't overflow and result in + // success. While this isn't much of a problem in the old solver, since we treat overflow + // fatally, this still can be encountered: . + Err(_overflow) => {} + } + } + + IntersectionHasImpossibleObligations::No { overflowing_predicates: Vec::new() } } } diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/type_err_ctxt_ext.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/type_err_ctxt_ext.rs index dcbb63f00f78b..0023fd602871d 100644 --- a/compiler/rustc_trait_selection/src/traits/error_reporting/type_err_ctxt_ext.rs +++ b/compiler/rustc_trait_selection/src/traits/error_reporting/type_err_ctxt_ext.rs @@ -20,10 +20,9 @@ use crate::traits::{ SelectionError, SignatureMismatch, TraitNotObjectSafe, }; use rustc_data_structures::fx::{FxHashMap, FxIndexMap}; -use rustc_errors::{ - codes::*, pluralize, struct_span_code_err, Applicability, Diag, ErrorGuaranteed, FatalError, - MultiSpan, StashKey, StringPart, -}; +use rustc_errors::codes::*; +use rustc_errors::{pluralize, struct_span_code_err, Applicability, MultiSpan, StringPart}; +use rustc_errors::{Diag, EmissionGuarantee, ErrorGuaranteed, FatalError, StashKey}; use rustc_hir as hir; use rustc_hir::def::{DefKind, Namespace, Res}; use rustc_hir::def_id::{DefId, LocalDefId}; @@ -62,6 +61,22 @@ pub enum OverflowCause<'tcx> { TraitSolver(ty::Predicate<'tcx>), } +pub fn suggest_new_overflow_limit<'tcx, G: EmissionGuarantee>( + tcx: TyCtxt<'tcx>, + err: &mut Diag<'_, G>, +) { + let suggested_limit = match tcx.recursion_limit() { + Limit(0) => Limit(2), + limit => limit * 2, + }; + err.help(format!( + "consider increasing the recursion limit by adding a \ + `#![recursion_limit = \"{}\"]` attribute to your crate (`{}`)", + suggested_limit, + tcx.crate_name(LOCAL_CRATE), + )); +} + #[extension(pub trait TypeErrCtxtExt<'tcx>)] impl<'tcx> TypeErrCtxt<'_, 'tcx> { fn report_fulfillment_errors( @@ -263,7 +278,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> { }; if suggest_increasing_limit { - self.suggest_new_overflow_limit(&mut err); + suggest_new_overflow_limit(self.tcx, &mut err); } err @@ -303,19 +318,6 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> { ); } - fn suggest_new_overflow_limit(&self, err: &mut Diag<'_>) { - let suggested_limit = match self.tcx.recursion_limit() { - Limit(0) => Limit(2), - limit => limit * 2, - }; - err.help(format!( - "consider increasing the recursion limit by adding a \ - `#![recursion_limit = \"{}\"]` attribute to your crate (`{}`)", - suggested_limit, - self.tcx.crate_name(LOCAL_CRATE), - )); - } - /// Reports that a cycle was detected which led to overflow and halts /// compilation. This is equivalent to `report_overflow_obligation` except /// that we can give a more helpful error message (and, in particular, @@ -335,12 +337,16 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> { ); } - fn report_overflow_no_abort(&self, obligation: PredicateObligation<'tcx>) -> ErrorGuaranteed { + fn report_overflow_no_abort( + &self, + obligation: PredicateObligation<'tcx>, + suggest_increasing_limit: bool, + ) -> ErrorGuaranteed { let obligation = self.resolve_vars_if_possible(obligation); let mut err = self.build_overflow_error( OverflowCause::TraitSolver(obligation.predicate), obligation.cause.span, - true, + suggest_increasing_limit, ); self.note_obligation_cause(&mut err, &obligation); self.point_at_returns_when_relevant(&mut err, &obligation); @@ -1422,11 +1428,11 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> { FulfillmentErrorCode::ProjectionError(ref e) => { self.report_projection_error(&error.obligation, e) } - FulfillmentErrorCode::Ambiguity { overflow: false } => { + FulfillmentErrorCode::Ambiguity { overflow: None } => { self.maybe_report_ambiguity(&error.obligation) } - FulfillmentErrorCode::Ambiguity { overflow: true } => { - self.report_overflow_no_abort(error.obligation.clone()) + FulfillmentErrorCode::Ambiguity { overflow: Some(suggest_increasing_limit) } => { + self.report_overflow_no_abort(error.obligation.clone(), suggest_increasing_limit) } FulfillmentErrorCode::SubtypeError(ref expected_found, ref err) => self .report_mismatched_types( diff --git a/compiler/rustc_trait_selection/src/traits/fulfill.rs b/compiler/rustc_trait_selection/src/traits/fulfill.rs index b91698af942e0..2fd64f474d5ad 100644 --- a/compiler/rustc_trait_selection/src/traits/fulfill.rs +++ b/compiler/rustc_trait_selection/src/traits/fulfill.rs @@ -138,7 +138,7 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentContext<'tcx> { _infcx: &InferCtxt<'tcx>, ) -> Vec> { self.predicates - .to_errors(FulfillmentErrorCode::Ambiguity { overflow: false }) + .to_errors(FulfillmentErrorCode::Ambiguity { overflow: None }) .into_iter() .map(to_fulfillment_error) .collect() diff --git a/compiler/rustc_trait_selection/src/traits/specialize/mod.rs b/compiler/rustc_trait_selection/src/traits/specialize/mod.rs index b329739609c98..f5bc6c3ad2c50 100644 --- a/compiler/rustc_trait_selection/src/traits/specialize/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/specialize/mod.rs @@ -39,6 +39,7 @@ pub struct OverlapError<'tcx> { pub self_ty: Option>, pub intercrate_ambiguity_causes: FxIndexSet>, pub involves_placeholder: bool, + pub overflowing_predicates: Vec>, } /// Given the generic parameters for the requested impl, translate it to the generic parameters @@ -435,6 +436,14 @@ fn report_conflicting_impls<'tcx>( if overlap.involves_placeholder { coherence::add_placeholder_note(err); } + + if !overlap.overflowing_predicates.is_empty() { + coherence::suggest_increasing_recursion_limit( + tcx, + err, + &overlap.overflowing_predicates, + ); + } } let msg = DelayDm(|| { diff --git a/compiler/rustc_trait_selection/src/traits/specialize/specialization_graph.rs b/compiler/rustc_trait_selection/src/traits/specialize/specialization_graph.rs index f3b77d689225c..95db9e2092fad 100644 --- a/compiler/rustc_trait_selection/src/traits/specialize/specialization_graph.rs +++ b/compiler/rustc_trait_selection/src/traits/specialize/specialization_graph.rs @@ -103,6 +103,7 @@ impl<'tcx> Children { self_ty: self_ty.has_concrete_skeleton().then_some(self_ty), intercrate_ambiguity_causes: overlap.intercrate_ambiguity_causes, involves_placeholder: overlap.involves_placeholder, + overflowing_predicates: overlap.overflowing_predicates, } }; diff --git a/tests/ui/higher-ranked/trait-bounds/issue-95230.next.stderr b/tests/ui/higher-ranked/trait-bounds/issue-95230.next.stderr index 6155579c9fa8f..9b0efe9abe611 100644 --- a/tests/ui/higher-ranked/trait-bounds/issue-95230.next.stderr +++ b/tests/ui/higher-ranked/trait-bounds/issue-95230.next.stderr @@ -4,7 +4,6 @@ error[E0275]: overflow evaluating the requirement `for<'a> &'a mut Bar well-form LL | for<'a> &'a mut Self:; | ^^^^^^^^^^^^ | - = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`issue_95230`) note: required by a bound in `Bar` --> $DIR/issue-95230.rs:9:13 | diff --git a/tests/ui/lazy-type-alias/inherent-impls-overflow.next.stderr b/tests/ui/lazy-type-alias/inherent-impls-overflow.next.stderr index 85e8061f173a3..80377bf6c2034 100644 --- a/tests/ui/lazy-type-alias/inherent-impls-overflow.next.stderr +++ b/tests/ui/lazy-type-alias/inherent-impls-overflow.next.stderr @@ -3,8 +3,6 @@ error[E0275]: overflow evaluating the requirement `Loop == _` | LL | impl Loop {} | ^^^^ - | - = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`inherent_impls_overflow`) error[E0392]: type parameter `T` is never used --> $DIR/inherent-impls-overflow.rs:13:12 diff --git a/tests/ui/traits/next-solver/alias-bound-unsound.stderr b/tests/ui/traits/next-solver/alias-bound-unsound.stderr index 2408e05728a84..a5c2f215134a9 100644 --- a/tests/ui/traits/next-solver/alias-bound-unsound.stderr +++ b/tests/ui/traits/next-solver/alias-bound-unsound.stderr @@ -4,7 +4,6 @@ error[E0275]: overflow evaluating the requirement `String: Copy` LL | type Item = String where String: Copy; | ^^^^ | - = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`alias_bound_unsound`) note: the requirement `String: Copy` appears on the `impl`'s associated type `Item` but not on the corresponding trait's associated type --> $DIR/alias-bound-unsound.rs:8:10 | @@ -18,32 +17,24 @@ error[E0275]: overflow evaluating the requirement `String <: <() as Foo>::Item` | LL | drop(<() as Foo>::copy_me(&x)); | ^^ - | - = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`alias_bound_unsound`) error[E0275]: overflow evaluating the requirement `<() as Foo>::Item == _` --> $DIR/alias-bound-unsound.rs:24:10 | LL | drop(<() as Foo>::copy_me(&x)); | ^^^^^^^^^^^^^^^^^^^^^^^^ - | - = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`alias_bound_unsound`) error[E0275]: overflow evaluating the requirement `&<() as Foo>::Item well-formed` --> $DIR/alias-bound-unsound.rs:24:31 | LL | drop(<() as Foo>::copy_me(&x)); | ^^ - | - = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`alias_bound_unsound`) error[E0275]: overflow evaluating the requirement `<() as Foo>::Item well-formed` --> $DIR/alias-bound-unsound.rs:24:10 | LL | drop(<() as Foo>::copy_me(&x)); | ^^^^^^^^^^^^^^^^^^^^^^^^ - | - = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`alias_bound_unsound`) error[E0275]: overflow evaluating the requirement `<() as Foo>::Item == _` --> $DIR/alias-bound-unsound.rs:24:10 @@ -51,7 +42,6 @@ error[E0275]: overflow evaluating the requirement `<() as Foo>::Item == _` LL | drop(<() as Foo>::copy_me(&x)); | ^^^^^^^^^^^^^^^^^^^^^^^^ | - = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`alias_bound_unsound`) = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no` error: aborting due to 6 previous errors diff --git a/tests/ui/traits/next-solver/coherence-fulfill-overflow.stderr b/tests/ui/traits/next-solver/coherence-fulfill-overflow.stderr index 406c0ccca9723..57cba790b5537 100644 --- a/tests/ui/traits/next-solver/coherence-fulfill-overflow.stderr +++ b/tests/ui/traits/next-solver/coherence-fulfill-overflow.stderr @@ -5,6 +5,9 @@ LL | impl Trait for W {} | ------------------------------------- first implementation here LL | impl Trait for T {} | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `W>>>>>>>>>>>>>>>>>>>>` + | + = note: overflow evaluating the requirement `W>>>>>>>>>>>>>>>>>>>>: TwoW` + = help: consider increasing the recursion limit by adding a `#![recursion_limit = "20"]` attribute to your crate (`coherence_fulfill_overflow`) error: aborting due to 1 previous error diff --git a/tests/ui/traits/next-solver/coherence/trait_ref_is_knowable-norm-overflow.stderr b/tests/ui/traits/next-solver/coherence/trait_ref_is_knowable-norm-overflow.stderr index fc145b811964b..a04fa1ab8a177 100644 --- a/tests/ui/traits/next-solver/coherence/trait_ref_is_knowable-norm-overflow.stderr +++ b/tests/ui/traits/next-solver/coherence/trait_ref_is_knowable-norm-overflow.stderr @@ -6,6 +6,9 @@ LL | impl Trait for T {} LL | struct LocalTy; LL | impl Trait for ::Assoc {} | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation + | + = note: overflow evaluating the requirement `_ == ::Assoc` + = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`trait_ref_is_knowable_norm_overflow`) error[E0275]: overflow evaluating the requirement `::Assoc: Sized` --> $DIR/trait_ref_is_knowable-norm-overflow.rs:10:18 diff --git a/tests/ui/traits/next-solver/cycles/coinduction/fixpoint-exponential-growth.stderr b/tests/ui/traits/next-solver/cycles/coinduction/fixpoint-exponential-growth.stderr index 150100f2c531c..8d7d8cee08ae3 100644 --- a/tests/ui/traits/next-solver/cycles/coinduction/fixpoint-exponential-growth.stderr +++ b/tests/ui/traits/next-solver/cycles/coinduction/fixpoint-exponential-growth.stderr @@ -4,7 +4,6 @@ error[E0275]: overflow evaluating the requirement `W<_>: Trait` 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:30:13 | diff --git a/tests/ui/traits/next-solver/cycles/double-cycle-inductive-coinductive.stderr b/tests/ui/traits/next-solver/cycles/double-cycle-inductive-coinductive.stderr index a3404da51f06a..7cedb4d36c98d 100644 --- a/tests/ui/traits/next-solver/cycles/double-cycle-inductive-coinductive.stderr +++ b/tests/ui/traits/next-solver/cycles/double-cycle-inductive-coinductive.stderr @@ -4,7 +4,6 @@ error[E0275]: overflow evaluating the requirement `(): Trait` LL | impls_trait::<()>(); | ^^ | - = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`double_cycle_inductive_coinductive`) note: required by a bound in `impls_trait` --> $DIR/double-cycle-inductive-coinductive.rs:17:19 | @@ -17,7 +16,6 @@ error[E0275]: overflow evaluating the requirement `(): TraitRev` LL | impls_trait_rev::<()>(); | ^^ | - = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`double_cycle_inductive_coinductive`) note: required by a bound in `impls_trait_rev` --> $DIR/double-cycle-inductive-coinductive.rs:29:23 | diff --git a/tests/ui/traits/next-solver/cycles/inductive-fixpoint-hang.stderr b/tests/ui/traits/next-solver/cycles/inductive-fixpoint-hang.stderr index 42451920744b0..a2a5c028cf8d5 100644 --- a/tests/ui/traits/next-solver/cycles/inductive-fixpoint-hang.stderr +++ b/tests/ui/traits/next-solver/cycles/inductive-fixpoint-hang.stderr @@ -4,7 +4,6 @@ error[E0275]: overflow evaluating the requirement `W<_>: Trait` LL | impls_trait::>(); | ^^^^ | - = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`inductive_fixpoint_hang`) note: required by a bound in `impls_trait` --> $DIR/inductive-fixpoint-hang.rs:28:19 | diff --git a/tests/ui/traits/next-solver/cycles/inductive-not-on-stack.stderr b/tests/ui/traits/next-solver/cycles/inductive-not-on-stack.stderr index 859b3f3f1c7d7..e9cc6bc6c81ad 100644 --- a/tests/ui/traits/next-solver/cycles/inductive-not-on-stack.stderr +++ b/tests/ui/traits/next-solver/cycles/inductive-not-on-stack.stderr @@ -4,7 +4,6 @@ error[E0275]: overflow evaluating the requirement `(): A` LL | impls_a::<()>(); | ^^ | - = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`inductive_not_on_stack`) note: required by a bound in `impls_a` --> $DIR/inductive-not-on-stack.rs:25:15 | @@ -17,7 +16,6 @@ error[E0275]: overflow evaluating the requirement `(): AR` LL | impls_ar::<()>(); | ^^ | - = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`inductive_not_on_stack`) note: required by a bound in `impls_ar` --> $DIR/inductive-not-on-stack.rs:38:16 | diff --git a/tests/ui/traits/next-solver/cycles/mixed-cycles-1.stderr b/tests/ui/traits/next-solver/cycles/mixed-cycles-1.stderr index e828bdeb16b69..17544eb1da528 100644 --- a/tests/ui/traits/next-solver/cycles/mixed-cycles-1.stderr +++ b/tests/ui/traits/next-solver/cycles/mixed-cycles-1.stderr @@ -4,7 +4,6 @@ error[E0275]: overflow evaluating the requirement `(): A` LL | impls_a::<()>(); | ^^ | - = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`mixed_cycles_1`) note: required by a bound in `impls_a` --> $DIR/mixed-cycles-1.rs:34:15 | diff --git a/tests/ui/traits/next-solver/cycles/mixed-cycles-2.stderr b/tests/ui/traits/next-solver/cycles/mixed-cycles-2.stderr index ec13093f707f4..a9be1016c7412 100644 --- a/tests/ui/traits/next-solver/cycles/mixed-cycles-2.stderr +++ b/tests/ui/traits/next-solver/cycles/mixed-cycles-2.stderr @@ -4,7 +4,6 @@ error[E0275]: overflow evaluating the requirement `(): A` LL | impls_a::<()>(); | ^^ | - = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`mixed_cycles_2`) note: required by a bound in `impls_a` --> $DIR/mixed-cycles-2.rs:27:15 | diff --git a/tests/ui/traits/next-solver/normalize-param-env-2.stderr b/tests/ui/traits/next-solver/normalize-param-env-2.stderr index 86729eb8a4b92..74a0a90885da5 100644 --- a/tests/ui/traits/next-solver/normalize-param-env-2.stderr +++ b/tests/ui/traits/next-solver/normalize-param-env-2.stderr @@ -4,7 +4,6 @@ error[E0275]: overflow evaluating the requirement `<() as A>::Assoc: A` LL | Self::Assoc: A, | ^^^^ | - = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`normalize_param_env_2`) note: the requirement `<() as A>::Assoc: A` appears on the `impl`'s method `f` but not on the corresponding trait's method --> $DIR/normalize-param-env-2.rs:12:8 | @@ -19,24 +18,18 @@ error[E0275]: overflow evaluating the requirement `<() as A>::Assoc: A` | LL | Self::Assoc: A, | ^^^^ - | - = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`normalize_param_env_2`) error[E0275]: overflow evaluating the requirement `<() as A>::Assoc well-formed` --> $DIR/normalize-param-env-2.rs:24:22 | LL | Self::Assoc: A, | ^^^^ - | - = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`normalize_param_env_2`) error[E0275]: overflow evaluating the requirement `(): A` --> $DIR/normalize-param-env-2.rs:27:10 | LL | <() as A>::f(); | ^^ - | - = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`normalize_param_env_2`) error[E0275]: overflow evaluating the requirement `<() as A>::Assoc: A` --> $DIR/normalize-param-env-2.rs:27:9 @@ -44,7 +37,6 @@ error[E0275]: overflow evaluating the requirement `<() as A>::Assoc: A` LL | <() as A>::f(); | ^^^^^^^^^^^^^^^^^ | - = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`normalize_param_env_2`) note: required by a bound in `A::f` --> $DIR/normalize-param-env-2.rs:14:22 | diff --git a/tests/ui/traits/next-solver/normalize-param-env-4.next.stderr b/tests/ui/traits/next-solver/normalize-param-env-4.next.stderr index 2a017fac10428..1bee8ee88ff18 100644 --- a/tests/ui/traits/next-solver/normalize-param-env-4.next.stderr +++ b/tests/ui/traits/next-solver/normalize-param-env-4.next.stderr @@ -3,16 +3,12 @@ error[E0275]: overflow evaluating the requirement `::Assoc: Trait` | LL | ::Assoc: Trait, | ^^^^^ - | - = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`normalize_param_env_4`) error[E0275]: overflow evaluating the requirement `::Assoc well-formed` --> $DIR/normalize-param-env-4.rs:18:26 | LL | ::Assoc: Trait, | ^^^^^ - | - = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`normalize_param_env_4`) error[E0275]: overflow evaluating the requirement `T: Trait` --> $DIR/normalize-param-env-4.rs:31:19 @@ -20,7 +16,6 @@ error[E0275]: overflow evaluating the requirement `T: Trait` LL | impls_trait::(); | ^ | - = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`normalize_param_env_4`) note: required by a bound in `impls_trait` --> $DIR/normalize-param-env-4.rs:14:19 | diff --git a/tests/ui/traits/next-solver/overflow/exponential-trait-goals.stderr b/tests/ui/traits/next-solver/overflow/exponential-trait-goals.stderr index 90b54b1e78980..b032ae3e740db 100644 --- a/tests/ui/traits/next-solver/overflow/exponential-trait-goals.stderr +++ b/tests/ui/traits/next-solver/overflow/exponential-trait-goals.stderr @@ -4,7 +4,6 @@ error[E0275]: overflow evaluating the requirement `W<_>: Trait` LL | impls::>(); | ^^^^ | - = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`exponential_trait_goals`) note: required by a bound in `impls` --> $DIR/exponential-trait-goals.rs:14:13 | diff --git a/tests/ui/traits/next-solver/overflow/recursion-limit-zero-issue-115351.rs b/tests/ui/traits/next-solver/overflow/recursion-limit-zero-issue-115351.rs index fb668f83b0188..1b80287d9da3b 100644 --- a/tests/ui/traits/next-solver/overflow/recursion-limit-zero-issue-115351.rs +++ b/tests/ui/traits/next-solver/overflow/recursion-limit-zero-issue-115351.rs @@ -1,12 +1,7 @@ -//~ ERROR overflow evaluating the requirement `Self well-formed` -//~| ERROR overflow evaluating the requirement `Self: Trait` - // This is a non-regression test for issue #115351, where a recursion limit of 0 caused an ICE. //@ compile-flags: -Znext-solver --crate-type=lib -//@ check-fail +//@ check-pass #![recursion_limit = "0"] trait Trait {} impl Trait for u32 {} -//~^ ERROR overflow evaluating the requirement `u32: Trait` -//~| ERROR overflow evaluating the requirement `u32 well-formed` diff --git a/tests/ui/traits/next-solver/overflow/recursion-limit-zero-issue-115351.stderr b/tests/ui/traits/next-solver/overflow/recursion-limit-zero-issue-115351.stderr deleted file mode 100644 index 16b25d90acec8..0000000000000 --- a/tests/ui/traits/next-solver/overflow/recursion-limit-zero-issue-115351.stderr +++ /dev/null @@ -1,27 +0,0 @@ -error[E0275]: overflow evaluating the requirement `Self: Trait` - | - = help: consider increasing the recursion limit by adding a `#![recursion_limit = "2"]` attribute to your crate (`recursion_limit_zero_issue_115351`) - -error[E0275]: overflow evaluating the requirement `Self well-formed` - | - = help: consider increasing the recursion limit by adding a `#![recursion_limit = "2"]` attribute to your crate (`recursion_limit_zero_issue_115351`) - -error[E0275]: overflow evaluating the requirement `u32: Trait` - --> $DIR/recursion-limit-zero-issue-115351.rs:10:16 - | -LL | impl Trait for u32 {} - | ^^^ - | - = help: consider increasing the recursion limit by adding a `#![recursion_limit = "2"]` attribute to your crate (`recursion_limit_zero_issue_115351`) - -error[E0275]: overflow evaluating the requirement `u32 well-formed` - --> $DIR/recursion-limit-zero-issue-115351.rs:10:16 - | -LL | impl Trait for u32 {} - | ^^^ - | - = help: consider increasing the recursion limit by adding a `#![recursion_limit = "2"]` attribute to your crate (`recursion_limit_zero_issue_115351`) - -error: aborting due to 4 previous errors - -For more information about this error, try `rustc --explain E0275`.