diff options
Diffstat (limited to 'compiler/rustc_next_trait_solver/src')
5 files changed, 68 insertions, 191 deletions
diff --git a/compiler/rustc_next_trait_solver/src/canonicalizer.rs b/compiler/rustc_next_trait_solver/src/canonicalizer.rs index 3e1f48610ff..da05c49756f 100644 --- a/compiler/rustc_next_trait_solver/src/canonicalizer.rs +++ b/compiler/rustc_next_trait_solver/src/canonicalizer.rs @@ -25,12 +25,8 @@ enum CanonicalizeInputKind { /// trait candidates relies on it when deciding whether a where-bound /// is trivial. ParamEnv, - /// When canonicalizing predicates, we don't keep `'static`. If we're - /// currently outside of the trait solver and canonicalize the root goal - /// during HIR typeck, we replace each occurrence of a region with a - /// unique region variable. See the comment on `InferCtxt::in_hir_typeck` - /// for more details. - Predicate { is_hir_typeck_root_goal: bool }, + /// When canonicalizing predicates, we don't keep `'static`. + Predicate, } /// Whether we're canonicalizing a query input or the query response. @@ -191,7 +187,6 @@ impl<'a, D: SolverDelegate<Interner = I>, I: Interner> Canonicalizer<'a, D, I> { pub fn canonicalize_input<P: TypeFoldable<I>>( delegate: &'a D, variables: &'a mut Vec<I::GenericArg>, - is_hir_typeck_root_goal: bool, input: QueryInput<I, P>, ) -> ty::Canonical<I, QueryInput<I, P>> { // First canonicalize the `param_env` while keeping `'static` @@ -201,9 +196,7 @@ impl<'a, D: SolverDelegate<Interner = I>, I: Interner> Canonicalizer<'a, D, I> { // while *mostly* reusing the canonicalizer from above. let mut rest_canonicalizer = Canonicalizer { delegate, - canonicalize_mode: CanonicalizeMode::Input(CanonicalizeInputKind::Predicate { - is_hir_typeck_root_goal, - }), + canonicalize_mode: CanonicalizeMode::Input(CanonicalizeInputKind::Predicate), variables, variable_lookup_table, @@ -481,31 +474,13 @@ impl<D: SolverDelegate<Interner = I>, I: Interner> TypeFolder<I> for Canonicaliz } }; - let var = if let CanonicalizeMode::Input(CanonicalizeInputKind::Predicate { - is_hir_typeck_root_goal: true, - }) = self.canonicalize_mode - { - let var = ty::BoundVar::from(self.variables.len()); - self.variables.push(r.into()); - self.var_kinds.push(kind); - var - } else { - self.get_or_insert_bound_var(r, kind) - }; + let var = self.get_or_insert_bound_var(r, kind); Region::new_anon_bound(self.cx(), self.binder_index, var) } fn fold_ty(&mut self, t: I::Ty) -> I::Ty { - if let CanonicalizeMode::Input(CanonicalizeInputKind::Predicate { - is_hir_typeck_root_goal: true, - }) = self.canonicalize_mode - { - // If we're canonicalizing a root goal during HIR typeck, we - // must not use the `cache` as we want to map each occurrence - // of a region to a unique existential variable. - self.inner_fold_ty(t) - } else if let Some(&ty) = self.cache.get(&(self.binder_index, t)) { + if let Some(&ty) = self.cache.get(&(self.binder_index, t)) { ty } else { let res = self.inner_fold_ty(t); diff --git a/compiler/rustc_next_trait_solver/src/solve/effect_goals.rs b/compiler/rustc_next_trait_solver/src/solve/effect_goals.rs index 9a22bf58c03..b7ae9994c62 100644 --- a/compiler/rustc_next_trait_solver/src/solve/effect_goals.rs +++ b/compiler/rustc_next_trait_solver/src/solve/effect_goals.rs @@ -6,7 +6,7 @@ use rustc_type_ir::inherent::*; use rustc_type_ir::lang_items::TraitSolverLangItem; use rustc_type_ir::solve::SizedTraitKind; use rustc_type_ir::solve::inspect::ProbeKind; -use rustc_type_ir::{self as ty, Interner, elaborate}; +use rustc_type_ir::{self as ty, Interner, TypingMode, elaborate}; use tracing::instrument; use super::assembly::{Candidate, structural_traits}; @@ -135,12 +135,16 @@ where } let impl_polarity = cx.impl_polarity(impl_def_id); - match impl_polarity { + let certainty = match impl_polarity { ty::ImplPolarity::Negative => return Err(NoSolution), - ty::ImplPolarity::Reservation => { - unimplemented!("reservation impl for const trait: {:?}", goal) - } - ty::ImplPolarity::Positive => {} + ty::ImplPolarity::Reservation => match ecx.typing_mode() { + TypingMode::Coherence => Certainty::AMBIGUOUS, + TypingMode::Analysis { .. } + | TypingMode::Borrowck { .. } + | TypingMode::PostBorrowckAnalysis { .. } + | TypingMode::PostAnalysis => return Err(NoSolution), + }, + ty::ImplPolarity::Positive => Certainty::Yes, }; if !cx.impl_is_const(impl_def_id) { @@ -171,7 +175,7 @@ where }); ecx.add_goals(GoalSource::ImplWhereBound, const_conditions); - ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) + ecx.evaluate_added_goals_and_make_canonical_response(certainty) }) } diff --git a/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/canonical.rs b/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/canonical.rs index 74c5b49ea92..4644b145b18 100644 --- a/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/canonical.rs +++ b/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/canonical.rs @@ -57,7 +57,6 @@ where /// This expects `goal` and `opaque_types` to be eager resolved. pub(super) fn canonicalize_goal( &self, - is_hir_typeck_root_goal: bool, goal: Goal<I, I::Predicate>, opaque_types: Vec<(ty::OpaqueTypeKey<I>, I::Ty)>, ) -> (Vec<I::GenericArg>, CanonicalInput<I, I::Predicate>) { @@ -65,7 +64,6 @@ where let canonical = Canonicalizer::canonicalize_input( self.delegate, &mut orig_values, - is_hir_typeck_root_goal, QueryInput { goal, predefined_opaques_in_body: self 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 a4738306181..4f87902e46e 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 @@ -4,7 +4,6 @@ use std::ops::ControlFlow; #[cfg(feature = "nightly")] use rustc_macros::HashStable_NoContext; use rustc_type_ir::data_structures::{HashMap, HashSet}; -use rustc_type_ir::fast_reject::DeepRejectCtxt; use rustc_type_ir::inherent::*; use rustc_type_ir::relate::Relate; use rustc_type_ir::relate::solver_relating::RelateExt; @@ -459,10 +458,7 @@ where let opaque_types = self.delegate.clone_opaque_types_lookup_table(); let (goal, opaque_types) = eager_resolve_vars(self.delegate, (goal, opaque_types)); - let is_hir_typeck_root_goal = matches!(goal_evaluation_kind, GoalEvaluationKind::Root) - && self.delegate.in_hir_typeck(); - let (orig_values, canonical_goal) = - self.canonicalize_goal(is_hir_typeck_root_goal, goal, opaque_types); + let (orig_values, canonical_goal) = self.canonicalize_goal(goal, opaque_types); let mut goal_evaluation = self.inspect.new_goal_evaluation(goal, &orig_values, goal_evaluation_kind); let canonical_result = self.search_graph.evaluate_goal( @@ -1131,6 +1127,7 @@ where self.delegate.fetch_eligible_assoc_item(goal_trait_ref, trait_assoc_def_id, impl_def_id) } + #[instrument(level = "debug", skip(self), ret)] pub(super) fn register_hidden_type_in_storage( &mut self, opaque_type_key: ty::OpaqueTypeKey<I>, @@ -1157,29 +1154,6 @@ where self.add_goals(GoalSource::AliasWellFormed, goals); } - // Do something for each opaque/hidden pair defined with `def_id` in the - // current inference context. - pub(super) fn probe_existing_opaque_ty( - &mut self, - key: ty::OpaqueTypeKey<I>, - ) -> Option<(ty::OpaqueTypeKey<I>, I::Ty)> { - // We shouldn't have any duplicate entries when using - // this function during `TypingMode::Analysis`. - let duplicate_entries = self.delegate.clone_duplicate_opaque_types(); - assert!(duplicate_entries.is_empty(), "unexpected duplicates: {duplicate_entries:?}"); - let mut matching = self.delegate.clone_opaque_types_lookup_table().into_iter().filter( - |(candidate_key, _)| { - candidate_key.def_id == key.def_id - && DeepRejectCtxt::relate_rigid_rigid(self.cx()) - .args_may_unify(candidate_key.args, key.args) - }, - ); - let first = matching.next(); - let second = matching.next(); - assert_eq!(second, None); - first - } - // Try to evaluate a const, or return `None` if the const is too generic. // This doesn't mean the const isn't evaluatable, though, and should be treated // as an ambiguity rather than no-solution. diff --git a/compiler/rustc_next_trait_solver/src/solve/normalizes_to/opaque_types.rs b/compiler/rustc_next_trait_solver/src/solve/normalizes_to/opaque_types.rs index df3ad1e468b..a5f857a1dd8 100644 --- a/compiler/rustc_next_trait_solver/src/solve/normalizes_to/opaque_types.rs +++ b/compiler/rustc_next_trait_solver/src/solve/normalizes_to/opaque_types.rs @@ -1,13 +1,12 @@ //! Computes a normalizes-to (projection) goal for opaque types. This goal //! behaves differently depending on the current `TypingMode`. -use rustc_index::bit_set::GrowableBitSet; use rustc_type_ir::inherent::*; use rustc_type_ir::solve::GoalSource; use rustc_type_ir::{self as ty, Interner, TypingMode, fold_regions}; use crate::delegate::SolverDelegate; -use crate::solve::{Certainty, EvalCtxt, Goal, NoSolution, QueryResult, inspect}; +use crate::solve::{Certainty, EvalCtxt, Goal, QueryResult}; impl<D, I> EvalCtxt<'_, D> where @@ -39,100 +38,68 @@ where self.add_goal(GoalSource::Misc, goal.with(cx, ty::PredicateKind::Ambiguous)); self.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) } - TypingMode::Analysis { defining_opaque_types_and_generators } => { + TypingMode::Analysis { + defining_opaque_types_and_generators: defining_opaque_types, + } + | TypingMode::Borrowck { defining_opaque_types } => { let Some(def_id) = opaque_ty .def_id .as_local() - .filter(|&def_id| defining_opaque_types_and_generators.contains(&def_id)) + .filter(|&def_id| defining_opaque_types.contains(&def_id)) else { + // If we're not in the defining scope, treat the alias as rigid. self.structurally_instantiate_normalizes_to_term(goal, goal.predicate.alias); return self.evaluate_added_goals_and_make_canonical_response(Certainty::Yes); }; - // FIXME: This may have issues when the args contain aliases... - match uses_unique_placeholders_ignoring_regions(self.cx(), opaque_ty.args) { - Err(NotUniqueParam::NotParam(param)) if param.is_non_region_infer() => { - return self.evaluate_added_goals_and_make_canonical_response( - Certainty::AMBIGUOUS, - ); - } - Err(_) => { - return Err(NoSolution); - } - Ok(()) => {} - } - // Prefer opaques registered already. - let opaque_type_key = ty::OpaqueTypeKey { def_id, args: opaque_ty.args }; - // FIXME: This also unifies the previous hidden type with the expected. + // We structurally normalize the args so that we're able to detect defining uses + // later on. // - // If that fails, we insert `expected` as a new hidden type instead of - // eagerly emitting an error. - let existing = self.probe_existing_opaque_ty(opaque_type_key); - if let Some((candidate_key, candidate_ty)) = existing { - return self - .probe(|result| inspect::ProbeKind::OpaqueTypeStorageLookup { - result: *result, - }) - .enter(|ecx| { - for (a, b) in std::iter::zip( - candidate_key.args.iter(), - opaque_type_key.args.iter(), - ) { - ecx.eq(goal.param_env, a, b)?; - } - ecx.eq(goal.param_env, candidate_ty, expected)?; - ecx.add_item_bounds_for_hidden_type( - def_id.into(), - candidate_key.args, - goal.param_env, - candidate_ty, - ); - ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) - }); - } + // This reduces the amount of duplicate definitions in the `opaque_type_storage` and + // strengthens inference. This causes us to subtly depend on the normalization behavior + // when inferring the hidden type of opaques. + // + // E.g. it's observable that we don't normalize nested aliases with bound vars in + // `structurally_normalize` and because we use structural lookup, we also don't + // reuse an entry for `Tait<for<'a> fn(&'a ())>` for `Tait<for<'b> fn(&'b ())>`. + let normalized_args = + cx.mk_args_from_iter(opaque_ty.args.iter().map(|arg| match arg.kind() { + ty::GenericArgKind::Lifetime(lt) => Ok(lt.into()), + ty::GenericArgKind::Type(ty) => { + self.structurally_normalize_ty(goal.param_env, ty).map(Into::into) + } + ty::GenericArgKind::Const(ct) => { + self.structurally_normalize_const(goal.param_env, ct).map(Into::into) + } + }))?; - // Otherwise, define a new opaque type - let prev = self.register_hidden_type_in_storage(opaque_type_key, expected); - assert_eq!(prev, None); - self.add_item_bounds_for_hidden_type( - def_id.into(), - opaque_ty.args, - goal.param_env, - expected, - ); - self.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) - } - // Very similar to `TypingMode::Analysis` with some notably differences: - // - we accept opaque types even if they have non-universal arguments - // - we do a structural lookup instead of semantically unifying regions - // - the hidden type starts out as the type from HIR typeck with fresh region - // variables instead of a fully unconstrained inference variable - TypingMode::Borrowck { defining_opaque_types } => { - let Some(def_id) = opaque_ty - .def_id - .as_local() - .filter(|&def_id| defining_opaque_types.contains(&def_id)) - else { - self.structurally_instantiate_normalizes_to_term(goal, goal.predicate.alias); - return self.evaluate_added_goals_and_make_canonical_response(Certainty::Yes); - }; + let opaque_type_key = ty::OpaqueTypeKey { def_id, args: normalized_args }; + if let Some(prev) = self.register_hidden_type_in_storage(opaque_type_key, expected) + { + self.eq(goal.param_env, expected, prev)?; + } else { + // During HIR typeck, opaque types start out as unconstrained + // inference variables. In borrowck we instead use the type + // computed in HIR typeck as the initial value. + match self.typing_mode() { + TypingMode::Analysis { .. } => {} + TypingMode::Borrowck { .. } => { + let actual = cx + .type_of_opaque_hir_typeck(def_id) + .instantiate(cx, opaque_ty.args); + let actual = fold_regions(cx, actual, |re, _dbi| match re.kind() { + ty::ReErased => self.next_region_var(), + _ => re, + }); + self.eq(goal.param_env, expected, actual)?; + } + _ => unreachable!(), + } + } - let opaque_type_key = ty::OpaqueTypeKey { def_id, args: opaque_ty.args }; - let actual = self - .register_hidden_type_in_storage(opaque_type_key, expected) - .unwrap_or_else(|| { - let actual = - cx.type_of_opaque_hir_typeck(def_id).instantiate(cx, opaque_ty.args); - let actual = fold_regions(cx, actual, |re, _dbi| match re.kind() { - ty::ReErased => self.next_region_var(), - _ => re, - }); - actual - }); - self.eq(goal.param_env, expected, actual)?; self.add_item_bounds_for_hidden_type( def_id.into(), - opaque_ty.args, + normalized_args, goal.param_env, expected, ); @@ -168,44 +135,3 @@ where } } } - -/// Checks whether each generic argument is simply a unique generic placeholder. -/// -/// FIXME: Interner argument is needed to constrain the `I` parameter. -fn uses_unique_placeholders_ignoring_regions<I: Interner>( - _cx: I, - args: I::GenericArgs, -) -> Result<(), NotUniqueParam<I>> { - let mut seen = GrowableBitSet::default(); - for arg in args.iter() { - match arg.kind() { - // Ignore regions, since we can't resolve those in a canonicalized - // query in the trait solver. - ty::GenericArgKind::Lifetime(_) => {} - ty::GenericArgKind::Type(t) => match t.kind() { - ty::Placeholder(p) => { - if !seen.insert(p.var()) { - return Err(NotUniqueParam::DuplicateParam(t.into())); - } - } - _ => return Err(NotUniqueParam::NotParam(t.into())), - }, - ty::GenericArgKind::Const(c) => match c.kind() { - ty::ConstKind::Placeholder(p) => { - if !seen.insert(p.var()) { - return Err(NotUniqueParam::DuplicateParam(c.into())); - } - } - _ => return Err(NotUniqueParam::NotParam(c.into())), - }, - } - } - - Ok(()) -} - -// FIXME: This should check for dupes and non-params first, then infer vars. -enum NotUniqueParam<I: Interner> { - DuplicateParam(I::GenericArg), - NotParam(I::GenericArg), -} |