Uplift inspect into rustc_type_ir

Author: compiler-errors

compiler/rustc_middle/src/arena.rs

@@ -61,7 +61,7 @@ macro_rules! arena_types {
             [] dtorck_constraint: rustc_middle::traits::query::DropckConstraint<'tcx>,
             [] candidate_step: rustc_middle::traits::query::CandidateStep<'tcx>,
             [] autoderef_bad_ty: rustc_middle::traits::query::MethodAutoderefBadTy<'tcx>,
-            [] canonical_goal_evaluation: rustc_middle::traits::solve::inspect::GoalEvaluationStep<'tcx>,
+            [] canonical_goal_evaluation: rustc_next_trait_solver::solve::inspect::GoalEvaluationStep<rustc_middle::ty::TyCtxt<'tcx>>,
             [] query_region_constraints: rustc_middle::infer::canonical::QueryRegionConstraints<'tcx>,
             [] type_op_subtype:
                 rustc_middle::infer::canonical::Canonical<'tcx,

compiler/rustc_middle/src/traits/mod.rs

@@ -9,7 +9,6 @@ pub mod specialization_graph;
 mod structural_impls;
 pub mod util;
 
-use crate::infer::canonical::Canonical;
 use crate::mir::ConstraintCategory;
 use crate::ty::abstract_const::NotConstEvaluatable;
 use crate::ty::GenericArgsRef;
@@ -32,6 +31,8 @@ use std::borrow::Cow;
 use std::hash::{Hash, Hasher};
 
 pub use self::select::{EvaluationCache, EvaluationResult, OverflowError, SelectionCache};
+// FIXME: Remove this import and import via `solve::`
+pub use rustc_next_trait_solver::solve::BuiltinImplSource;
 
 /// Depending on the stage of compilation, we want projection to be
 /// more or less conservative.
@@ -736,32 +737,6 @@ pub struct ImplSourceUserDefinedData<'tcx, N> {
     pub nested: Vec<N>,
 }
 
-#[derive(Copy, Clone, PartialEq, Eq, TyEncodable, TyDecodable, HashStable, Debug)]
-pub enum BuiltinImplSource {
-    /// Some builtin impl we don't need to differentiate. This should be used
-    /// unless more specific information is necessary.
-    Misc,
-    /// A builtin impl for trait objects.
-    ///
-    /// The vtable is formed by concatenating together the method lists of
-    /// the base object trait and all supertraits, pointers to supertrait vtable will
-    /// be provided when necessary; this is the start of `upcast_trait_ref`'s methods
-    /// in that vtable.
-    Object { vtable_base: usize },
-    /// The vtable is formed by concatenating together the method lists of
-    /// the base object trait and all supertraits, pointers to supertrait vtable will
-    /// be provided when necessary; this is the position of `upcast_trait_ref`'s vtable
-    /// within that vtable.
-    TraitUpcasting { vtable_vptr_slot: Option<usize> },
-    /// Unsizing a tuple like `(A, B, ..., X)` to `(A, B, ..., Y)` if `X` unsizes to `Y`.
-    ///
-    /// This needs to be a separate variant as it is still unstable and we need to emit
-    /// a feature error when using it on stable.
-    TupleUnsizing,
-}
-
-TrivialTypeTraversalImpls! { BuiltinImplSource }
-
 #[derive(Clone, Debug, PartialEq, Eq, Hash, HashStable, PartialOrd, Ord)]
 pub enum ObjectSafetyViolation {
     /// `Self: Sized` declared on the trait.

compiler/rustc_middle/src/traits/query.rs

@@ -12,6 +12,8 @@ use crate::ty::GenericArg;
 use crate::ty::{self, Ty, TyCtxt};
 use rustc_macros::{HashStable, TypeFoldable, TypeVisitable};
 use rustc_span::Span;
+// FIXME: Remove this import and import via `traits::solve`.
+pub use rustc_next_trait_solver::solve::NoSolution;
 
 pub mod type_op {
     use crate::ty::fold::TypeFoldable;
@@ -89,9 +91,6 @@ pub type CanonicalTypeOpProvePredicateGoal<'tcx> =
 pub type CanonicalTypeOpNormalizeGoal<'tcx, T> =
     Canonical<'tcx, ty::ParamEnvAnd<'tcx, type_op::Normalize<T>>>;
 
-#[derive(Copy, Clone, Debug, Hash, HashStable, PartialEq, Eq)]
-pub struct NoSolution;
-
 impl<'tcx> From<TypeError<'tcx>> for NoSolution {
     fn from(_: TypeError<'tcx>) -> NoSolution {
         NoSolution

compiler/rustc_middle/src/traits/solve.rs

@@ -3,92 +3,22 @@ use rustc_data_structures::intern::Interned;
 use rustc_macros::{HashStable, TypeFoldable, TypeVisitable};
 use rustc_next_trait_solver::solve as ir_solve;
 pub use rustc_next_trait_solver::solve::*;
-use rustc_span::def_id::DefId;
 
-use crate::infer::canonical::{CanonicalVarValues, QueryRegionConstraints};
-use crate::traits::query::NoSolution;
-use crate::traits::Canonical;
+use crate::infer::canonical::QueryRegionConstraints;
 use crate::ty::{
     self, FallibleTypeFolder, Ty, TyCtxt, TypeFoldable, TypeFolder, TypeVisitable, TypeVisitor,
 };
 
-use super::BuiltinImplSource;
-
 mod cache;
-pub mod inspect;
 
 pub use cache::{CacheData, EvaluationCache};
 
 pub type Goal<'tcx, P> = ir_solve::Goal<TyCtxt<'tcx>, P>;
 pub type QueryInput<'tcx, P> = ir_solve::QueryInput<TyCtxt<'tcx>, P>;
-
-#[derive(Debug, PartialEq, Eq, Clone, Copy, Hash, HashStable, TypeFoldable, TypeVisitable)]
-pub struct Response<'tcx> {
-    pub certainty: Certainty,
-    pub var_values: CanonicalVarValues<'tcx>,
-    /// Additional constraints returned by this query.
-    pub external_constraints: ExternalConstraints<'tcx>,
-}
-
-#[derive(Debug, PartialEq, Eq, Clone, Copy, Hash, HashStable, TypeFoldable, TypeVisitable)]
-pub enum Certainty {
-    Yes,
-    Maybe(MaybeCause),
-}
-
-impl Certainty {
-    pub const AMBIGUOUS: Certainty = Certainty::Maybe(MaybeCause::Ambiguity);
-
-    /// Use this function to merge the certainty of multiple nested subgoals.
-    ///
-    /// Given an impl like `impl<T: Foo + Bar> Baz for T {}`, we have 2 nested
-    /// subgoals whenever we use the impl as a candidate: `T: Foo` and `T: Bar`.
-    /// If evaluating `T: Foo` results in ambiguity and `T: Bar` results in
-    /// success, we merge these two responses. This results in ambiguity.
-    ///
-    /// If we unify ambiguity with overflow, we return overflow. This doesn't matter
-    /// inside of the solver as we do not distinguish ambiguity from overflow. It does
-    /// however matter for diagnostics. If `T: Foo` resulted in overflow and `T: Bar`
-    /// in ambiguity without changing the inference state, we still want to tell the
-    /// user that `T: Baz` results in overflow.
-    pub fn unify_with(self, other: Certainty) -> Certainty {
-        match (self, other) {
-            (Certainty::Yes, Certainty::Yes) => Certainty::Yes,
-            (Certainty::Yes, Certainty::Maybe(_)) => other,
-            (Certainty::Maybe(_), Certainty::Yes) => self,
-            (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.
-#[derive(Debug, PartialEq, Eq, Clone, Copy, Hash, HashStable, TypeFoldable, TypeVisitable)]
-pub enum MaybeCause {
-    /// We failed due to ambiguity. This ambiguity can either
-    /// be a true ambiguity, i.e. there are multiple different answers,
-    /// 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 { 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 },
-        }
-    }
-}
+pub type QueryResult<'tcx> = ir_solve::QueryResult<TyCtxt<'tcx>>;
+pub type CandidateSource<'tcx> = ir_solve::CandidateSource<TyCtxt<'tcx>>;
+pub type CanonicalInput<'tcx, P = ty::Predicate<'tcx>> = ir_solve::CanonicalInput<TyCtxt<'tcx>, P>;
+pub type CanonicalResponse<'tcx> = ir_solve::CanonicalResponse<TyCtxt<'tcx>>;
 
 /// Additional constraints returned on success.
 #[derive(Debug, PartialEq, Eq, Clone, Hash, HashStable, Default)]
@@ -107,18 +37,6 @@ impl<'tcx> std::ops::Deref for PredefinedOpaques<'tcx> {
     }
 }
 
-pub type CanonicalInput<'tcx, T = ty::Predicate<'tcx>> = Canonical<'tcx, QueryInput<'tcx, T>>;
-
-pub type CanonicalResponse<'tcx> = Canonical<'tcx, Response<'tcx>>;
-
-/// The result of evaluating a canonical query.
-///
-/// FIXME: We use a different type than the existing canonical queries. This is because
-/// we need to add a `Certainty` for `overflow` and may want to restructure this code without
-/// having to worry about changes to currently used code. Once we've made progress on this
-/// solver, merge the two responses again.
-pub type QueryResult<'tcx> = Result<CanonicalResponse<'tcx>, NoSolution>;
-
 #[derive(Debug, PartialEq, Eq, Copy, Clone, Hash, HashStable)]
 pub struct ExternalConstraints<'tcx>(pub(crate) Interned<'tcx, ExternalConstraintsData<'tcx>>);
 
@@ -225,68 +143,3 @@ impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for PredefinedOpaques<'tcx> {
         self.opaque_types.visit_with(visitor)
     }
 }
-
-/// Possible ways the given goal can be proven.
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-pub enum CandidateSource {
-    /// A user written impl.
-    ///
-    /// ## Examples
-    ///
-    /// ```rust
-    /// fn main() {
-    ///     let x: Vec<u32> = Vec::new();
-    ///     // This uses the impl from the standard library to prove `Vec<T>: Clone`.
-    ///     let y = x.clone();
-    /// }
-    /// ```
-    Impl(DefId),
-    /// A builtin impl generated by the compiler. When adding a new special
-    /// trait, try to use actual impls whenever possible. Builtin impls should
-    /// only be used in cases where the impl cannot be manually be written.
-    ///
-    /// Notable examples are auto traits, `Sized`, and `DiscriminantKind`.
-    /// For a list of all traits with builtin impls, check out the
-    /// `EvalCtxt::assemble_builtin_impl_candidates` method.
-    BuiltinImpl(BuiltinImplSource),
-    /// An assumption from the environment.
-    ///
-    /// More precisely we've used the `n-th` assumption in the `param_env`.
-    ///
-    /// ## Examples
-    ///
-    /// ```rust
-    /// fn is_clone<T: Clone>(x: T) -> (T, T) {
-    ///     // This uses the assumption `T: Clone` from the `where`-bounds
-    ///     // to prove `T: Clone`.
-    ///     (x.clone(), x)
-    /// }
-    /// ```
-    ParamEnv(usize),
-    /// If the self type is an alias type, e.g. an opaque type or a projection,
-    /// we know the bounds on that alias to hold even without knowing its concrete
-    /// underlying type.
-    ///
-    /// More precisely this candidate is using the `n-th` bound in the `item_bounds` of
-    /// the self type.
-    ///
-    /// ## Examples
-    ///
-    /// ```rust
-    /// trait Trait {
-    ///     type Assoc: Clone;
-    /// }
-    ///
-    /// fn foo<T: Trait>(x: <T as Trait>::Assoc) {
-    ///     // We prove `<T as Trait>::Assoc` by looking at the bounds on `Assoc` in
-    ///     // in the trait definition.
-    ///     let _y = x.clone();
-    /// }
-    /// ```
-    AliasBound,
-    /// A candidate that is registered only during coherence to represent some
-    /// yet-unknown impl that could be produced downstream without violating orphan
-    /// rules.
-    // FIXME: Merge this with the forced ambiguity candidates, so those don't use `Misc`.
-    CoherenceUnknowable,
-}

compiler/rustc_middle/src/traits/solve/cache.rs

@@ -17,7 +17,7 @@ pub struct EvaluationCache<'tcx> {
 #[derive(PartialEq, Eq)]
 pub struct CacheData<'tcx> {
     pub result: QueryResult<'tcx>,
-    pub proof_tree: Option<&'tcx [inspect::GoalEvaluationStep<'tcx>]>,
+    pub proof_tree: Option<&'tcx [inspect::GoalEvaluationStep<TyCtxt<'tcx>>]>,
     pub reached_depth: usize,
     pub encountered_overflow: bool,
 }
@@ -28,7 +28,7 @@ impl<'tcx> EvaluationCache<'tcx> {
         &self,
         tcx: TyCtxt<'tcx>,
         key: CanonicalInput<'tcx>,
-        proof_tree: Option<&'tcx [inspect::GoalEvaluationStep<'tcx>]>,
+        proof_tree: Option<&'tcx [inspect::GoalEvaluationStep<TyCtxt<'tcx>>]>,
         reached_depth: usize,
         encountered_overflow: bool,
         cycle_participants: FxHashSet<CanonicalInput<'tcx>>,
@@ -105,7 +105,7 @@ struct Success<'tcx> {
 #[derive(Clone, Copy)]
 pub struct QueryData<'tcx> {
     pub result: QueryResult<'tcx>,
-    pub proof_tree: Option<&'tcx [inspect::GoalEvaluationStep<'tcx>]>,
+    pub proof_tree: Option<&'tcx [inspect::GoalEvaluationStep<TyCtxt<'tcx>>]>,
 }
 
 /// The cache entry for a goal `CanonicalInput`.

compiler/rustc_middle/src/ty/context.rs

@@ -89,19 +89,23 @@ use std::ops::{Bound, Deref};
 #[allow(rustc::usage_of_ty_tykind)]
 impl<'tcx> Interner for TyCtxt<'tcx> {
     type DefId = DefId;
-    type DefiningOpaqueTypes = &'tcx ty::List<LocalDefId>;
-    type PredefinedOpaques = solve::PredefinedOpaques<'tcx>;
     type AdtDef = ty::AdtDef<'tcx>;
+
     type GenericArgs = ty::GenericArgsRef<'tcx>;
     type OwnItemArgs = &'tcx [ty::GenericArg<'tcx>];
     type GenericArg = ty::GenericArg<'tcx>;
-
     type Term = ty::Term<'tcx>;
+
     type Binder<T: TypeVisitable<TyCtxt<'tcx>>> = Binder<'tcx, T>;
     type BoundVars = &'tcx List<ty::BoundVariableKind>;
     type BoundVar = ty::BoundVariableKind;
 
     type CanonicalVars = CanonicalVarInfos<'tcx>;
+    type PredefinedOpaques = solve::PredefinedOpaques<'tcx>;
+    type DefiningOpaqueTypes = &'tcx ty::List<LocalDefId>;
+    type ExternalConstraints = ExternalConstraints<'tcx>;
+    type GoalEvaluationSteps = &'tcx [solve::inspect::GoalEvaluationStep<TyCtxt<'tcx>>];
+
     type Ty = Ty<'tcx>;
     type Tys = &'tcx List<Ty<'tcx>>;
     type FnInputTys = &'tcx [Ty<'tcx>];

compiler/rustc_trait_selection/src/solve/assembly/mod.rs

@@ -25,7 +25,7 @@ pub(super) mod structural_traits;
 /// and the `result` when using the given `source`.
 #[derive(Debug, Clone)]
 pub(super) struct Candidate<'tcx> {
-    pub(super) source: CandidateSource,
+    pub(super) source: CandidateSource<'tcx>,
     pub(super) result: CanonicalResponse<'tcx>,
 }
 
@@ -47,7 +47,7 @@ pub(super) trait GoalKind<'tcx>:
     /// [`EvalCtxt::evaluate_added_goals_and_make_canonical_response`]).
     fn probe_and_match_goal_against_assumption(
         ecx: &mut EvalCtxt<'_, 'tcx>,
-        source: CandidateSource,
+        source: CandidateSource<'tcx>,
         goal: Goal<'tcx, Self>,
         assumption: ty::Clause<'tcx>,
         then: impl FnOnce(&mut EvalCtxt<'_, 'tcx>) -> QueryResult<'tcx>,
@@ -58,7 +58,7 @@ pub(super) trait GoalKind<'tcx>:
     /// goal by equating it with the assumption.
     fn probe_and_consider_implied_clause(
         ecx: &mut EvalCtxt<'_, 'tcx>,
-        parent_source: CandidateSource,
+        parent_source: CandidateSource<'tcx>,
         goal: Goal<'tcx, Self>,
         assumption: ty::Clause<'tcx>,
         requirements: impl IntoIterator<Item = (GoalSource, Goal<'tcx, ty::Predicate<'tcx>>)>,
@@ -76,7 +76,7 @@ pub(super) trait GoalKind<'tcx>:
     /// since they're not implied by the well-formedness of the object type.
     fn probe_and_consider_object_bound_candidate(
         ecx: &mut EvalCtxt<'_, 'tcx>,
-        source: CandidateSource,
+        source: CandidateSource<'tcx>,
         goal: Goal<'tcx, Self>,
         assumption: ty::Clause<'tcx>,
     ) -> Result<Candidate<'tcx>, NoSolution> {

compiler/rustc_trait_selection/src/solve/eval_ctxt/canonical.rs

@@ -40,13 +40,13 @@ trait ResponseT<'tcx> {
     fn var_values(&self) -> CanonicalVarValues<'tcx>;
 }
 
-impl<'tcx> ResponseT<'tcx> for Response<'tcx> {
+impl<'tcx> ResponseT<'tcx> for Response<TyCtxt<'tcx>> {
     fn var_values(&self) -> CanonicalVarValues<'tcx> {
         self.var_values
     }
 }
 
-impl<'tcx, T> ResponseT<'tcx> for inspect::State<'tcx, T> {
+impl<'tcx, T> ResponseT<'tcx> for inspect::State<TyCtxt<'tcx>, T> {
     fn var_values(&self) -> CanonicalVarValues<'tcx> {
         self.var_values
     }
@@ -384,7 +384,7 @@ pub(in crate::solve) fn make_canonical_state<'tcx, T: TypeFoldable<TyCtxt<'tcx>>
     var_values: &[ty::GenericArg<'tcx>],
     max_input_universe: ty::UniverseIndex,
     data: T,
-) -> inspect::CanonicalState<'tcx, T> {
+) -> inspect::CanonicalState<TyCtxt<'tcx>, T> {
     let var_values = CanonicalVarValues { var_values: infcx.tcx.mk_args(var_values) };
     let state = inspect::State { var_values, data };
     let state = state.fold_with(&mut EagerResolver::new(infcx));
@@ -414,7 +414,7 @@ pub(in crate::solve) fn instantiate_canonical_state<'tcx, T: TypeFoldable<TyCtxt
     span: Span,
     param_env: ty::ParamEnv<'tcx>,
     orig_values: &mut Vec<ty::GenericArg<'tcx>>,
-    state: inspect::CanonicalState<'tcx, T>,
+    state: inspect::CanonicalState<TyCtxt<'tcx>, T>,
 ) -> T {
     // In case any fresh inference variables have been created between `state`
     // and the previous instantiation, extend `orig_values` for it.