From b83c0f0e94592d1a7eae1124e4e951f331ccf6c8 Mon Sep 17 00:00:00 2001 From: lcnr Date: Tue, 16 Sep 2025 15:30:25 +0200 Subject: canonical: yeet `EvalCtxt`, mk `Canonicalizer` private --- .../src/canonical/canonicalizer.rs | 7 +- .../rustc_next_trait_solver/src/canonical/mod.rs | 419 +++++++++++---------- .../src/solve/eval_ctxt/mod.rs | 18 +- 3 files changed, 233 insertions(+), 211 deletions(-) (limited to 'compiler') diff --git a/compiler/rustc_next_trait_solver/src/canonical/canonicalizer.rs b/compiler/rustc_next_trait_solver/src/canonical/canonicalizer.rs index 4b4ec4956eb..b25671d676b 100644 --- a/compiler/rustc_next_trait_solver/src/canonical/canonicalizer.rs +++ b/compiler/rustc_next_trait_solver/src/canonical/canonicalizer.rs @@ -57,7 +57,7 @@ enum CanonicalizeMode { }, } -pub struct Canonicalizer<'a, D: SolverDelegate, I: Interner> { +pub(super) struct Canonicalizer<'a, D: SolverDelegate, I: Interner> { delegate: &'a D, // Immutable field. @@ -83,7 +83,7 @@ pub struct Canonicalizer<'a, D: SolverDelegate, I: Interner> { } impl<'a, D: SolverDelegate, I: Interner> Canonicalizer<'a, D, I> { - pub fn canonicalize_response>( + pub(super) fn canonicalize_response>( delegate: &'a D, max_input_universe: ty::UniverseIndex, variables: &'a mut Vec, @@ -112,7 +112,6 @@ impl<'a, D: SolverDelegate, I: Interner> Canonicalizer<'a, D, I> { let (max_universe, variables) = canonicalizer.finalize(); Canonical { max_universe, variables, value } } - fn canonicalize_param_env( delegate: &'a D, variables: &'a mut Vec, @@ -195,7 +194,7 @@ impl<'a, D: SolverDelegate, I: Interner> Canonicalizer<'a, D, I> { /// /// We want to keep the option of canonicalizing `'static` to an existential /// variable in the future by changing the way we detect global where-bounds. - pub fn canonicalize_input>( + pub(super) fn canonicalize_input>( delegate: &'a D, variables: &'a mut Vec, input: QueryInput, diff --git a/compiler/rustc_next_trait_solver/src/canonical/mod.rs b/compiler/rustc_next_trait_solver/src/canonical/mod.rs index 35881acf0c7..e3520e238ed 100644 --- a/compiler/rustc_next_trait_solver/src/canonical/mod.rs +++ b/compiler/rustc_next_trait_solver/src/canonical/mod.rs @@ -24,7 +24,7 @@ use tracing::instrument; use crate::delegate::SolverDelegate; use crate::resolve::eager_resolve_vars; use crate::solve::{ - CanonicalInput, CanonicalResponse, Certainty, EvalCtxt, ExternalConstraintsData, Goal, + CanonicalInput, CanonicalResponse, Certainty, ExternalConstraintsData, Goal, NestedNormalizationGoals, PredefinedOpaquesData, QueryInput, Response, inspect, }; @@ -46,226 +46,248 @@ impl ResponseT for inspect::State { } } -impl EvalCtxt<'_, D> +/// Canonicalizes the goal remembering the original values +/// for each bound variable. +/// +/// This expects `goal` and `opaque_types` to be eager resolved. +pub(super) fn canonicalize_goal( + delegate: &D, + goal: Goal, + opaque_types: Vec<(ty::OpaqueTypeKey, I::Ty)>, +) -> (Vec, CanonicalInput) where D: SolverDelegate, I: Interner, { - /// Canonicalizes the goal remembering the original values - /// for each bound variable. - /// - /// This expects `goal` and `opaque_types` to be eager resolved. - pub(super) fn canonicalize_goal( - delegate: &D, - goal: Goal, - opaque_types: Vec<(ty::OpaqueTypeKey, I::Ty)>, - ) -> (Vec, CanonicalInput) { - let mut orig_values = Default::default(); - let canonical = Canonicalizer::canonicalize_input( - delegate, - &mut orig_values, - QueryInput { - goal, - predefined_opaques_in_body: delegate - .cx() - .mk_predefined_opaques_in_body(PredefinedOpaquesData { opaque_types }), - }, - ); - let query_input = - ty::CanonicalQueryInput { canonical, typing_mode: delegate.typing_mode() }; - (orig_values, query_input) - } + let mut orig_values = Default::default(); + let canonical = Canonicalizer::canonicalize_input( + delegate, + &mut orig_values, + QueryInput { + goal, + predefined_opaques_in_body: delegate + .cx() + .mk_predefined_opaques_in_body(PredefinedOpaquesData { opaque_types }), + }, + ); + let query_input = ty::CanonicalQueryInput { canonical, typing_mode: delegate.typing_mode() }; + (orig_values, query_input) +} - /// After calling a canonical query, we apply the constraints returned - /// by the query using this function. - /// - /// This happens in three steps: - /// - we instantiate the bound variables of the query response - /// - we unify the `var_values` of the response with the `original_values` - /// - we apply the `external_constraints` returned by the query, returning - /// the `normalization_nested_goals` - pub(super) fn instantiate_and_apply_query_response( - delegate: &D, - param_env: I::ParamEnv, - original_values: &[I::GenericArg], - response: CanonicalResponse, - span: I::Span, - ) -> (NestedNormalizationGoals, Certainty) { - let instantiation = Self::compute_query_response_instantiation_values( - delegate, - &original_values, - &response, - span, - ); +pub(super) fn canonicalize_response( + delegate: &D, + max_input_universe: ty::UniverseIndex, + value: T, +) -> ty::Canonical +where + D: SolverDelegate, + I: Interner, + T: TypeFoldable, +{ + let mut orig_values = Default::default(); + let canonical = + Canonicalizer::canonicalize_response(delegate, max_input_universe, &mut orig_values, value); + canonical +} - let Response { var_values, external_constraints, certainty } = - delegate.instantiate_canonical(response, instantiation); +/// After calling a canonical query, we apply the constraints returned +/// by the query using this function. +/// +/// This happens in three steps: +/// - we instantiate the bound variables of the query response +/// - we unify the `var_values` of the response with the `original_values` +/// - we apply the `external_constraints` returned by the query, returning +/// the `normalization_nested_goals` +pub(super) fn instantiate_and_apply_query_response( + delegate: &D, + param_env: I::ParamEnv, + original_values: &[I::GenericArg], + response: CanonicalResponse, + span: I::Span, +) -> (NestedNormalizationGoals, Certainty) +where + D: SolverDelegate, + I: Interner, +{ + let instantiation = + compute_query_response_instantiation_values(delegate, &original_values, &response, span); - Self::unify_query_var_values(delegate, param_env, &original_values, var_values, span); + let Response { var_values, external_constraints, certainty } = + delegate.instantiate_canonical(response, instantiation); - let ExternalConstraintsData { - region_constraints, - opaque_types, - normalization_nested_goals, - } = &*external_constraints; + unify_query_var_values(delegate, param_env, &original_values, var_values, span); - Self::register_region_constraints(delegate, region_constraints, span); - Self::register_new_opaque_types(delegate, opaque_types, span); + let ExternalConstraintsData { region_constraints, opaque_types, normalization_nested_goals } = + &*external_constraints; - (normalization_nested_goals.clone(), certainty) - } + register_region_constraints(delegate, region_constraints, span); + register_new_opaque_types(delegate, opaque_types, span); - /// This returns the canonical variable values to instantiate the bound variables of - /// the canonical response. This depends on the `original_values` for the - /// bound variables. - fn compute_query_response_instantiation_values>( - delegate: &D, - original_values: &[I::GenericArg], - response: &Canonical, - span: I::Span, - ) -> CanonicalVarValues { - // FIXME: Longterm canonical queries should deal with all placeholders - // created inside of the query directly instead of returning them to the - // caller. - let prev_universe = delegate.universe(); - let universes_created_in_query = response.max_universe.index(); - for _ in 0..universes_created_in_query { - delegate.create_next_universe(); - } + (normalization_nested_goals.clone(), certainty) +} + +/// This returns the canonical variable values to instantiate the bound variables of +/// the canonical response. This depends on the `original_values` for the +/// bound variables. +fn compute_query_response_instantiation_values( + delegate: &D, + original_values: &[I::GenericArg], + response: &Canonical, + span: I::Span, +) -> CanonicalVarValues +where + D: SolverDelegate, + I: Interner, + T: ResponseT, +{ + // FIXME: Longterm canonical queries should deal with all placeholders + // created inside of the query directly instead of returning them to the + // caller. + let prev_universe = delegate.universe(); + let universes_created_in_query = response.max_universe.index(); + for _ in 0..universes_created_in_query { + delegate.create_next_universe(); + } - let var_values = response.value.var_values(); - assert_eq!(original_values.len(), var_values.len()); + let var_values = response.value.var_values(); + assert_eq!(original_values.len(), var_values.len()); - // If the query did not make progress with constraining inference variables, - // we would normally create a new inference variables for bound existential variables - // only then unify this new inference variable with the inference variable from - // the input. - // - // We therefore instantiate the existential variable in the canonical response with the - // inference variable of the input right away, which is more performant. - let mut opt_values = IndexVec::from_elem_n(None, response.variables.len()); - for (original_value, result_value) in - iter::zip(original_values, var_values.var_values.iter()) - { - match result_value.kind() { - ty::GenericArgKind::Type(t) => { - // We disable the instantiation guess for inference variables - // and only use it for placeholders. We need to handle the - // `sub_root` of type inference variables which would make this - // more involved. They are also a lot rarer than region variables. - if let ty::Bound(debruijn, b) = t.kind() - && !matches!( - response.variables.get(b.var().as_usize()).unwrap(), - CanonicalVarKind::Ty { .. } - ) - { - assert_eq!(debruijn, ty::INNERMOST); - opt_values[b.var()] = Some(*original_value); - } + // If the query did not make progress with constraining inference variables, + // we would normally create a new inference variables for bound existential variables + // only then unify this new inference variable with the inference variable from + // the input. + // + // We therefore instantiate the existential variable in the canonical response with the + // inference variable of the input right away, which is more performant. + let mut opt_values = IndexVec::from_elem_n(None, response.variables.len()); + for (original_value, result_value) in iter::zip(original_values, var_values.var_values.iter()) { + match result_value.kind() { + ty::GenericArgKind::Type(t) => { + // We disable the instantiation guess for inference variables + // and only use it for placeholders. We need to handle the + // `sub_root` of type inference variables which would make this + // more involved. They are also a lot rarer than region variables. + if let ty::Bound(debruijn, b) = t.kind() + && !matches!( + response.variables.get(b.var().as_usize()).unwrap(), + CanonicalVarKind::Ty { .. } + ) + { + assert_eq!(debruijn, ty::INNERMOST); + opt_values[b.var()] = Some(*original_value); } - ty::GenericArgKind::Lifetime(r) => { - if let ty::ReBound(debruijn, br) = r.kind() { - assert_eq!(debruijn, ty::INNERMOST); - opt_values[br.var()] = Some(*original_value); - } + } + ty::GenericArgKind::Lifetime(r) => { + if let ty::ReBound(debruijn, br) = r.kind() { + assert_eq!(debruijn, ty::INNERMOST); + opt_values[br.var()] = Some(*original_value); } - ty::GenericArgKind::Const(c) => { - if let ty::ConstKind::Bound(debruijn, bv) = c.kind() { - assert_eq!(debruijn, ty::INNERMOST); - opt_values[bv.var()] = Some(*original_value); - } + } + ty::GenericArgKind::Const(c) => { + if let ty::ConstKind::Bound(debruijn, bv) = c.kind() { + assert_eq!(debruijn, ty::INNERMOST); + opt_values[bv.var()] = Some(*original_value); } } } - CanonicalVarValues::instantiate(delegate.cx(), response.variables, |var_values, kind| { - if kind.universe() != ty::UniverseIndex::ROOT { - // A variable from inside a binder of the query. While ideally these shouldn't - // exist at all (see the FIXME at the start of this method), we have to deal with - // them for now. - delegate.instantiate_canonical_var(kind, span, &var_values, |idx| { - prev_universe + idx.index() - }) - } else if kind.is_existential() { - // As an optimization we sometimes avoid creating a new inference variable here. - // - // All new inference variables we create start out in the current universe of the caller. - // This is conceptually wrong as these inference variables would be able to name - // more placeholders then they should be able to. However the inference variables have - // to "come from somewhere", so by equating them with the original values of the caller - // later on, we pull them down into their correct universe again. - if let Some(v) = opt_values[ty::BoundVar::from_usize(var_values.len())] { - v - } else { - delegate.instantiate_canonical_var(kind, span, &var_values, |_| prev_universe) - } + } + CanonicalVarValues::instantiate(delegate.cx(), response.variables, |var_values, kind| { + if kind.universe() != ty::UniverseIndex::ROOT { + // A variable from inside a binder of the query. While ideally these shouldn't + // exist at all (see the FIXME at the start of this method), we have to deal with + // them for now. + delegate.instantiate_canonical_var(kind, span, &var_values, |idx| { + prev_universe + idx.index() + }) + } else if kind.is_existential() { + // As an optimization we sometimes avoid creating a new inference variable here. + // + // All new inference variables we create start out in the current universe of the caller. + // This is conceptually wrong as these inference variables would be able to name + // more placeholders then they should be able to. However the inference variables have + // to "come from somewhere", so by equating them with the original values of the caller + // later on, we pull them down into their correct universe again. + if let Some(v) = opt_values[ty::BoundVar::from_usize(var_values.len())] { + v } else { - // For placeholders which were already part of the input, we simply map this - // universal bound variable back the placeholder of the input. - original_values[kind.expect_placeholder_index()] + delegate.instantiate_canonical_var(kind, span, &var_values, |_| prev_universe) } - }) - } + } else { + // For placeholders which were already part of the input, we simply map this + // universal bound variable back the placeholder of the input. + original_values[kind.expect_placeholder_index()] + } + }) +} - /// Unify the `original_values` with the `var_values` returned by the canonical query.. - /// - /// This assumes that this unification will always succeed. This is the case when - /// applying a query response right away. However, calling a canonical query, doing any - /// other kind of trait solving, and only then instantiating the result of the query - /// can cause the instantiation to fail. This is not supported and we ICE in this case. - /// - /// We always structurally instantiate aliases. Relating aliases needs to be different - /// depending on whether the alias is *rigid* or not. We're only really able to tell - /// whether an alias is rigid by using the trait solver. When instantiating a response - /// from the solver we assume that the solver correctly handled aliases and therefore - /// always relate them structurally here. - #[instrument(level = "trace", skip(delegate))] - fn unify_query_var_values( - delegate: &D, - param_env: I::ParamEnv, - original_values: &[I::GenericArg], - var_values: CanonicalVarValues, - span: I::Span, - ) { - assert_eq!(original_values.len(), var_values.len()); +/// Unify the `original_values` with the `var_values` returned by the canonical query.. +/// +/// This assumes that this unification will always succeed. This is the case when +/// applying a query response right away. However, calling a canonical query, doing any +/// other kind of trait solving, and only then instantiating the result of the query +/// can cause the instantiation to fail. This is not supported and we ICE in this case. +/// +/// We always structurally instantiate aliases. Relating aliases needs to be different +/// depending on whether the alias is *rigid* or not. We're only really able to tell +/// whether an alias is rigid by using the trait solver. When instantiating a response +/// from the solver we assume that the solver correctly handled aliases and therefore +/// always relate them structurally here. +#[instrument(level = "trace", skip(delegate))] +fn unify_query_var_values( + delegate: &D, + param_env: I::ParamEnv, + original_values: &[I::GenericArg], + var_values: CanonicalVarValues, + span: I::Span, +) where + D: SolverDelegate, + I: Interner, +{ + assert_eq!(original_values.len(), var_values.len()); - for (&orig, response) in iter::zip(original_values, var_values.var_values.iter()) { - let goals = - delegate.eq_structurally_relating_aliases(param_env, orig, response, span).unwrap(); - assert!(goals.is_empty()); - } + for (&orig, response) in iter::zip(original_values, var_values.var_values.iter()) { + let goals = + delegate.eq_structurally_relating_aliases(param_env, orig, response, span).unwrap(); + assert!(goals.is_empty()); } +} - fn register_region_constraints( - delegate: &D, - outlives: &[ty::OutlivesPredicate], - span: I::Span, - ) { - for &ty::OutlivesPredicate(lhs, rhs) in outlives { - match lhs.kind() { - ty::GenericArgKind::Lifetime(lhs) => delegate.sub_regions(rhs, lhs, span), - ty::GenericArgKind::Type(lhs) => delegate.register_ty_outlives(lhs, rhs, span), - ty::GenericArgKind::Const(_) => panic!("const outlives: {lhs:?}: {rhs:?}"), - } +fn register_region_constraints( + delegate: &D, + outlives: &[ty::OutlivesPredicate], + span: I::Span, +) where + D: SolverDelegate, + I: Interner, +{ + for &ty::OutlivesPredicate(lhs, rhs) in outlives { + match lhs.kind() { + ty::GenericArgKind::Lifetime(lhs) => delegate.sub_regions(rhs, lhs, span), + ty::GenericArgKind::Type(lhs) => delegate.register_ty_outlives(lhs, rhs, span), + ty::GenericArgKind::Const(_) => panic!("const outlives: {lhs:?}: {rhs:?}"), } } +} - fn register_new_opaque_types( - delegate: &D, - opaque_types: &[(ty::OpaqueTypeKey, I::Ty)], - span: I::Span, - ) { - for &(key, ty) in opaque_types { - let prev = delegate.register_hidden_type_in_storage(key, ty, span); - // We eagerly resolve inference variables when computing the query response. - // This can cause previously distinct opaque type keys to now be structurally equal. - // - // To handle this, we store any duplicate entries in a separate list to check them - // at the end of typeck/borrowck. We could alternatively eagerly equate the hidden - // types here. However, doing so is difficult as it may result in nested goals and - // any errors may make it harder to track the control flow for diagnostics. - if let Some(prev) = prev { - delegate.add_duplicate_opaque_type(key, prev, span); - } +fn register_new_opaque_types( + delegate: &D, + opaque_types: &[(ty::OpaqueTypeKey, I::Ty)], + span: I::Span, +) where + D: SolverDelegate, + I: Interner, +{ + for &(key, ty) in opaque_types { + let prev = delegate.register_hidden_type_in_storage(key, ty, span); + // We eagerly resolve inference variables when computing the query response. + // This can cause previously distinct opaque type keys to now be structurally equal. + // + // To handle this, we store any duplicate entries in a separate list to check them + // at the end of typeck/borrowck. We could alternatively eagerly equate the hidden + // types here. However, doing so is difficult as it may result in nested goals and + // any errors may make it harder to track the control flow for diagnostics. + if let Some(prev) = prev { + delegate.add_duplicate_opaque_type(key, prev, span); } } } @@ -274,7 +296,7 @@ where /// evaluating a goal. The `var_values` not only include the bound variables /// of the query input, but also contain all unconstrained inference vars /// created while evaluating this goal. -pub fn make_canonical_state( +pub fn make_canonical_state( delegate: &D, var_values: &[I::GenericArg], max_input_universe: ty::UniverseIndex, @@ -293,7 +315,7 @@ where // FIXME: needs to be pub to be accessed by downstream // `rustc_trait_selection::solve::inspect::analyse`. -pub fn instantiate_canonical_state>( +pub fn instantiate_canonical_state( delegate: &D, span: I::Span, param_env: I::ParamEnv, @@ -303,6 +325,7 @@ pub fn instantiate_canonical_state>( where D: SolverDelegate, I: Interner, + T: TypeFoldable, { // In case any fresh inference variables have been created between `state` // and the previous instantiation, extend `orig_values` for it. @@ -313,11 +336,11 @@ where ); let instantiation = - EvalCtxt::compute_query_response_instantiation_values(delegate, orig_values, &state, span); + compute_query_response_instantiation_values(delegate, orig_values, &state, span); let inspect::State { var_values, data } = delegate.instantiate_canonical(state, instantiation); - EvalCtxt::unify_query_var_values(delegate, param_env, orig_values, var_values, span); + unify_query_var_values(delegate, param_env, orig_values, var_values, span); data } diff --git a/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/mod.rs b/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/mod.rs index 8f9b68dbac4..bb86357a85f 100644 --- a/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/mod.rs +++ b/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/mod.rs @@ -17,8 +17,10 @@ use rustc_type_ir::{ use tracing::{debug, instrument, trace}; use super::has_only_region_constraints; -use crate::canonical::canonicalizer::Canonicalizer; -use crate::canonical::response_no_constraints_raw; +use crate::canonical::{ + canonicalize_goal, canonicalize_response, instantiate_and_apply_query_response, + response_no_constraints_raw, +}; use crate::coherence; use crate::delegate::SolverDelegate; use crate::placeholder::BoundVarReplacer; @@ -465,8 +467,7 @@ where let opaque_types = self.delegate.clone_opaque_types_lookup_table(); let (goal, opaque_types) = eager_resolve_vars(self.delegate, (goal, opaque_types)); - let (orig_values, canonical_goal) = - Self::canonicalize_goal(self.delegate, goal, opaque_types); + let (orig_values, canonical_goal) = canonicalize_goal(self.delegate, goal, opaque_types); let canonical_result = self.search_graph.evaluate_goal( self.cx(), canonical_goal, @@ -481,7 +482,7 @@ where let has_changed = if !has_only_region_constraints(response) { HasChanged::Yes } else { HasChanged::No }; - let (normalization_nested_goals, certainty) = Self::instantiate_and_apply_query_response( + let (normalization_nested_goals, certainty) = instantiate_and_apply_query_response( self.delegate, goal.param_env, &orig_values, @@ -1319,10 +1320,9 @@ where outlives.0.as_region().is_none_or(|re| re != outlives.1) && unique.insert(*outlives) }); - let canonical = Canonicalizer::canonicalize_response( + let canonical = canonicalize_response( self.delegate, self.max_input_universe, - &mut Default::default(), Response { var_values, certainty, @@ -1557,7 +1557,7 @@ pub(super) fn evaluate_root_goal_for_proof_tree, let opaque_types = delegate.clone_opaque_types_lookup_table(); let (goal, opaque_types) = eager_resolve_vars(delegate, (goal, opaque_types)); - let (orig_values, canonical_goal) = EvalCtxt::canonicalize_goal(delegate, goal, opaque_types); + let (orig_values, canonical_goal) = canonicalize_goal(delegate, goal, opaque_types); let (canonical_result, final_revision) = delegate.cx().evaluate_root_goal_for_proof_tree_raw(canonical_goal); @@ -1574,7 +1574,7 @@ pub(super) fn evaluate_root_goal_for_proof_tree, Ok(response) => response, }; - let (normalization_nested_goals, _certainty) = EvalCtxt::instantiate_and_apply_query_response( + let (normalization_nested_goals, _certainty) = instantiate_and_apply_query_response( delegate, goal.param_env, &proof_tree.orig_values, -- cgit 1.4.1-3-g733a5