diff options
Diffstat (limited to 'compiler/rustc_next_trait_solver')
5 files changed, 63 insertions, 74 deletions
diff --git a/compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs b/compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs index 231fb3e2964..5e08c3a03d8 100644 --- a/compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs +++ b/compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs @@ -959,36 +959,23 @@ where // Even when a trait bound has been proven using a where-bound, we // still need to consider alias-bounds for normalization, see // `tests/ui/next-solver/alias-bound-shadowed-by-env.rs`. - let candidates_from_env_and_bounds: Vec<_> = self + let mut candidates: Vec<_> = self .assemble_and_evaluate_candidates(goal, AssembleCandidatesFrom::EnvAndBounds); // We still need to prefer where-bounds over alias-bounds however. // See `tests/ui/winnowing/norm-where-bound-gt-alias-bound.rs`. - let mut considered_candidates: Vec<_> = if candidates_from_env_and_bounds - .iter() - .any(|c| matches!(c.source, CandidateSource::ParamEnv(_))) - { - candidates_from_env_and_bounds - .into_iter() - .filter(|c| matches!(c.source, CandidateSource::ParamEnv(_))) - .map(|c| c.result) - .collect() - } else { - candidates_from_env_and_bounds.into_iter().map(|c| c.result).collect() - }; - - // If the trait goal has been proven by using the environment, we want to treat - // aliases as rigid if there are no applicable projection bounds in the environment. - if considered_candidates.is_empty() { - if let Ok(response) = inject_normalize_to_rigid_candidate(self) { - considered_candidates.push(response); - } + if candidates.iter().any(|c| matches!(c.source, CandidateSource::ParamEnv(_))) { + candidates.retain(|c| matches!(c.source, CandidateSource::ParamEnv(_))); + } else if candidates.is_empty() { + // If the trait goal has been proven by using the environment, we want to treat + // aliases as rigid if there are no applicable projection bounds in the environment. + return inject_normalize_to_rigid_candidate(self); } - if let Some(response) = self.try_merge_responses(&considered_candidates) { + if let Some(response) = self.try_merge_candidates(&candidates) { Ok(response) } else { - self.flounder(&considered_candidates) + self.flounder(&candidates) } } TraitGoalProvenVia::Misc => { @@ -998,11 +985,9 @@ where // Prefer "orphaned" param-env normalization predicates, which are used // (for example, and ideally only) when proving item bounds for an impl. let candidates_from_env: Vec<_> = candidates - .iter() - .filter(|c| matches!(c.source, CandidateSource::ParamEnv(_))) - .map(|c| c.result) + .extract_if(.., |c| matches!(c.source, CandidateSource::ParamEnv(_))) .collect(); - if let Some(response) = self.try_merge_responses(&candidates_from_env) { + if let Some(response) = self.try_merge_candidates(&candidates_from_env) { return Ok(response); } @@ -1012,12 +997,10 @@ where // means we can just ignore inference constraints and don't have to special-case // constraining the normalized-to `term`. self.filter_specialized_impls(AllowInferenceConstraints::Yes, &mut candidates); - - let responses: Vec<_> = candidates.iter().map(|c| c.result).collect(); - if let Some(response) = self.try_merge_responses(&responses) { + if let Some(response) = self.try_merge_candidates(&candidates) { Ok(response) } else { - self.flounder(&responses) + self.flounder(&candidates) } } } diff --git a/compiler/rustc_next_trait_solver/src/solve/inspect/build.rs b/compiler/rustc_next_trait_solver/src/solve/inspect/build.rs index c8521624ebb..fc56b006d94 100644 --- a/compiler/rustc_next_trait_solver/src/solve/inspect/build.rs +++ b/compiler/rustc_next_trait_solver/src/solve/inspect/build.rs @@ -68,7 +68,7 @@ impl<I: Interner> From<WipCanonicalGoalEvaluationStep<I>> for DebugSolver<I> { } } -#[derive_where(PartialEq, Eq, Debug; I: Interner)] +#[derive_where(PartialEq, Debug; I: Interner)] struct WipGoalEvaluation<I: Interner> { pub uncanonicalized_goal: Goal<I, I::Predicate>, pub orig_values: Vec<I::GenericArg>, @@ -78,6 +78,8 @@ struct WipGoalEvaluation<I: Interner> { pub result: Option<QueryResult<I>>, } +impl<I: Interner> Eq for WipGoalEvaluation<I> {} + impl<I: Interner> WipGoalEvaluation<I> { fn finalize(self) -> inspect::GoalEvaluation<I> { inspect::GoalEvaluation { @@ -98,7 +100,7 @@ impl<I: Interner> WipGoalEvaluation<I> { /// This only exists during proof tree building and does not have /// a corresponding struct in `inspect`. We need this to track a /// bunch of metadata about the current evaluation. -#[derive_where(PartialEq, Eq, Debug; I: Interner)] +#[derive_where(PartialEq, Debug; I: Interner)] struct WipCanonicalGoalEvaluationStep<I: Interner> { /// Unlike `EvalCtxt::var_values`, we append a new /// generic arg here whenever we create a new inference @@ -111,6 +113,8 @@ struct WipCanonicalGoalEvaluationStep<I: Interner> { evaluation: WipProbe<I>, } +impl<I: Interner> Eq for WipCanonicalGoalEvaluationStep<I> {} + impl<I: Interner> WipCanonicalGoalEvaluationStep<I> { fn current_evaluation_scope(&mut self) -> &mut WipProbe<I> { let mut current = &mut self.evaluation; @@ -132,7 +136,7 @@ impl<I: Interner> WipCanonicalGoalEvaluationStep<I> { } } -#[derive_where(PartialEq, Eq, Debug; I: Interner)] +#[derive_where(PartialEq, Debug; I: Interner)] struct WipProbe<I: Interner> { initial_num_var_values: usize, steps: Vec<WipProbeStep<I>>, @@ -140,6 +144,8 @@ struct WipProbe<I: Interner> { final_state: Option<inspect::CanonicalState<I, ()>>, } +impl<I: Interner> Eq for WipProbe<I> {} + impl<I: Interner> WipProbe<I> { fn finalize(self) -> inspect::Probe<I> { inspect::Probe { @@ -150,7 +156,7 @@ impl<I: Interner> WipProbe<I> { } } -#[derive_where(PartialEq, Eq, Debug; I: Interner)] +#[derive_where(PartialEq, Debug; I: Interner)] enum WipProbeStep<I: Interner> { AddGoal(GoalSource, inspect::CanonicalState<I, Goal<I, I::Predicate>>), NestedProbe(WipProbe<I>), @@ -158,6 +164,8 @@ enum WipProbeStep<I: Interner> { RecordImplArgs { impl_args: inspect::CanonicalState<I, I::GenericArgs> }, } +impl<I: Interner> Eq for WipProbeStep<I> {} + impl<I: Interner> WipProbeStep<I> { fn finalize(self) -> inspect::ProbeStep<I> { match self { diff --git a/compiler/rustc_next_trait_solver/src/solve/mod.rs b/compiler/rustc_next_trait_solver/src/solve/mod.rs index aec9594b834..2feebe270a6 100644 --- a/compiler/rustc_next_trait_solver/src/solve/mod.rs +++ b/compiler/rustc_next_trait_solver/src/solve/mod.rs @@ -29,6 +29,7 @@ use tracing::instrument; pub use self::eval_ctxt::{EvalCtxt, GenerateProofTree, SolverDelegateEvalExt}; use crate::delegate::SolverDelegate; +use crate::solve::assembly::Candidate; /// How many fixpoint iterations we should attempt inside of the solver before bailing /// with overflow. @@ -244,50 +245,51 @@ where /// /// In this case we tend to flounder and return ambiguity by calling `[EvalCtxt::flounder]`. #[instrument(level = "trace", skip(self), ret)] - fn try_merge_responses( + fn try_merge_candidates( &mut self, - responses: &[CanonicalResponse<I>], + candidates: &[Candidate<I>], ) -> Option<CanonicalResponse<I>> { - if responses.is_empty() { + if candidates.is_empty() { return None; } - let one = responses[0]; - if responses[1..].iter().all(|&resp| resp == one) { + let one: CanonicalResponse<I> = candidates[0].result; + if candidates[1..].iter().all(|candidate| candidate.result == one) { return Some(one); } - responses + candidates .iter() - .find(|response| { - response.value.certainty == Certainty::Yes - && has_no_inference_or_external_constraints(**response) + .find(|candidate| { + candidate.result.value.certainty == Certainty::Yes + && has_no_inference_or_external_constraints(candidate.result) }) - .copied() + .map(|candidate| candidate.result) } - fn bail_with_ambiguity(&mut self, responses: &[CanonicalResponse<I>]) -> CanonicalResponse<I> { - debug_assert!(responses.len() > 1); - let maybe_cause = responses.iter().fold(MaybeCause::Ambiguity, |maybe_cause, response| { - // Pull down the certainty of `Certainty::Yes` to ambiguity when combining - // these responses, b/c we're combining more than one response and this we - // don't know which one applies. - let candidate = match response.value.certainty { - Certainty::Yes => MaybeCause::Ambiguity, - Certainty::Maybe(candidate) => candidate, - }; - maybe_cause.or(candidate) - }); + fn bail_with_ambiguity(&mut self, candidates: &[Candidate<I>]) -> CanonicalResponse<I> { + debug_assert!(candidates.len() > 1); + let maybe_cause = + candidates.iter().fold(MaybeCause::Ambiguity, |maybe_cause, candidates| { + // Pull down the certainty of `Certainty::Yes` to ambiguity when combining + // these responses, b/c we're combining more than one response and this we + // don't know which one applies. + let candidate = match candidates.result.value.certainty { + Certainty::Yes => MaybeCause::Ambiguity, + Certainty::Maybe(candidate) => candidate, + }; + maybe_cause.or(candidate) + }); self.make_ambiguous_response_no_constraints(maybe_cause) } /// If we fail to merge responses we flounder and return overflow or ambiguity. #[instrument(level = "trace", skip(self), ret)] - fn flounder(&mut self, responses: &[CanonicalResponse<I>]) -> QueryResult<I> { - if responses.is_empty() { + fn flounder(&mut self, candidates: &[Candidate<I>]) -> QueryResult<I> { + if candidates.is_empty() { return Err(NoSolution); } else { - Ok(self.bail_with_ambiguity(responses)) + Ok(self.bail_with_ambiguity(candidates)) } } diff --git a/compiler/rustc_next_trait_solver/src/solve/search_graph.rs b/compiler/rustc_next_trait_solver/src/solve/search_graph.rs index 12cbc7e8f91..84f8eda4f8d 100644 --- a/compiler/rustc_next_trait_solver/src/solve/search_graph.rs +++ b/compiler/rustc_next_trait_solver/src/solve/search_graph.rs @@ -48,7 +48,9 @@ where ) -> QueryResult<I> { match kind { PathKind::Coinductive => response_no_constraints(cx, input, Certainty::Yes), - PathKind::Unknown => response_no_constraints(cx, input, Certainty::overflow(false)), + PathKind::Unknown | PathKind::ForcedAmbiguity => { + response_no_constraints(cx, input, Certainty::overflow(false)) + } // Even though we know these cycles to be unproductive, we still return // overflow during coherence. This is both as we are not 100% confident in // the implementation yet and any incorrect errors would be unsound there. diff --git a/compiler/rustc_next_trait_solver/src/solve/trait_goals.rs b/compiler/rustc_next_trait_solver/src/solve/trait_goals.rs index f760c2c07ff..60bae738e61 100644 --- a/compiler/rustc_next_trait_solver/src/solve/trait_goals.rs +++ b/compiler/rustc_next_trait_solver/src/solve/trait_goals.rs @@ -1346,11 +1346,10 @@ where mut candidates: Vec<Candidate<I>>, ) -> Result<(CanonicalResponse<I>, Option<TraitGoalProvenVia>), NoSolution> { if let TypingMode::Coherence = self.typing_mode() { - let all_candidates: Vec<_> = candidates.into_iter().map(|c| c.result).collect(); - return if let Some(response) = self.try_merge_responses(&all_candidates) { + return if let Some(response) = self.try_merge_candidates(&candidates) { Ok((response, Some(TraitGoalProvenVia::Misc))) } else { - self.flounder(&all_candidates).map(|r| (r, None)) + self.flounder(&candidates).map(|r| (r, None)) }; } @@ -1375,11 +1374,9 @@ where .any(|c| matches!(c.source, CandidateSource::ParamEnv(ParamEnvSource::NonGlobal))); if has_non_global_where_bounds { let where_bounds: Vec<_> = candidates - .iter() - .filter(|c| matches!(c.source, CandidateSource::ParamEnv(_))) - .map(|c| c.result) + .extract_if(.., |c| matches!(c.source, CandidateSource::ParamEnv(_))) .collect(); - return if let Some(response) = self.try_merge_responses(&where_bounds) { + return if let Some(response) = self.try_merge_candidates(&where_bounds) { Ok((response, Some(TraitGoalProvenVia::ParamEnv))) } else { Ok((self.bail_with_ambiguity(&where_bounds), None)) @@ -1388,11 +1385,9 @@ where if candidates.iter().any(|c| matches!(c.source, CandidateSource::AliasBound)) { let alias_bounds: Vec<_> = candidates - .iter() - .filter(|c| matches!(c.source, CandidateSource::AliasBound)) - .map(|c| c.result) + .extract_if(.., |c| matches!(c.source, CandidateSource::AliasBound)) .collect(); - return if let Some(response) = self.try_merge_responses(&alias_bounds) { + return if let Some(response) = self.try_merge_candidates(&alias_bounds) { Ok((response, Some(TraitGoalProvenVia::AliasBound))) } else { Ok((self.bail_with_ambiguity(&alias_bounds), None)) @@ -1417,11 +1412,10 @@ where TraitGoalProvenVia::Misc }; - let all_candidates: Vec<_> = candidates.into_iter().map(|c| c.result).collect(); - if let Some(response) = self.try_merge_responses(&all_candidates) { + if let Some(response) = self.try_merge_candidates(&candidates) { Ok((response, Some(proven_via))) } else { - self.flounder(&all_candidates).map(|r| (r, None)) + self.flounder(&candidates).map(|r| (r, None)) } } |