From 6232ba8d08d200fd9fc862076d4991a599fdc0da Mon Sep 17 00:00:00 2001 From: Chayim Refael Friedman Date: Fri, 17 Oct 2025 05:14:02 +0300 Subject: [PATCH] Migrate variance to the new solver --- .../crates/hir-ty/src/chalk_db.rs | 48 +- .../crates/hir-ty/src/chalk_ext.rs | 21 +- .../rust-analyzer/crates/hir-ty/src/db.rs | 9 +- .../rust-analyzer/crates/hir-ty/src/lib.rs | 1 - .../crates/hir-ty/src/next_solver/def_id.rs | 4 +- .../crates/hir-ty/src/next_solver/interner.rs | 52 ++- .../crates/hir-ty/src/next_solver/mapping.rs | 36 +- .../crates/hir-ty/src/variance.rs | 442 +++++++----------- src/tools/rust-analyzer/crates/hir/src/lib.rs | 37 +- 9 files changed, 227 insertions(+), 423 deletions(-) diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/chalk_db.rs b/src/tools/rust-analyzer/crates/hir-ty/src/chalk_db.rs index 3d06b5210670..a6b859b37210 100644 --- a/src/tools/rust-analyzer/crates/hir-ty/src/chalk_db.rs +++ b/src/tools/rust-analyzer/crates/hir-ty/src/chalk_db.rs @@ -1,55 +1,9 @@ //! The implementation of `RustIrDatabase` for Chalk, which provides information //! about the code that Chalk needs. -use hir_def::{CallableDefId, GenericDefId}; -use crate::{Interner, db::HirDatabase, mapping::from_chalk}; +use crate::Interner; pub(crate) type AssocTypeId = chalk_ir::AssocTypeId; pub(crate) type TraitId = chalk_ir::TraitId; pub(crate) type AdtId = chalk_ir::AdtId; pub(crate) type ImplId = chalk_ir::ImplId; -pub(crate) type Variances = chalk_ir::Variances; - -impl chalk_ir::UnificationDatabase for &dyn HirDatabase { - fn fn_def_variance( - &self, - fn_def_id: chalk_ir::FnDefId, - ) -> chalk_ir::Variances { - HirDatabase::fn_def_variance(*self, from_chalk(*self, fn_def_id)) - } - - fn adt_variance(&self, adt_id: chalk_ir::AdtId) -> chalk_ir::Variances { - HirDatabase::adt_variance(*self, adt_id.0) - } -} - -pub(crate) fn fn_def_variance_query( - db: &dyn HirDatabase, - callable_def: CallableDefId, -) -> Variances { - Variances::from_iter( - Interner, - db.variances_of(GenericDefId::from_callable(db, callable_def)) - .as_deref() - .unwrap_or_default() - .iter() - .map(|v| match v { - crate::variance::Variance::Covariant => chalk_ir::Variance::Covariant, - crate::variance::Variance::Invariant => chalk_ir::Variance::Invariant, - crate::variance::Variance::Contravariant => chalk_ir::Variance::Contravariant, - crate::variance::Variance::Bivariant => chalk_ir::Variance::Invariant, - }), - ) -} - -pub(crate) fn adt_variance_query(db: &dyn HirDatabase, adt_id: hir_def::AdtId) -> Variances { - Variances::from_iter( - Interner, - db.variances_of(adt_id.into()).as_deref().unwrap_or_default().iter().map(|v| match v { - crate::variance::Variance::Covariant => chalk_ir::Variance::Covariant, - crate::variance::Variance::Invariant => chalk_ir::Variance::Invariant, - crate::variance::Variance::Contravariant => chalk_ir::Variance::Contravariant, - crate::variance::Variance::Bivariant => chalk_ir::Variance::Invariant, - }), - ) -} diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/chalk_ext.rs b/src/tools/rust-analyzer/crates/hir-ty/src/chalk_ext.rs index a315f699ddaa..4ea563d46e6e 100644 --- a/src/tools/rust-analyzer/crates/hir-ty/src/chalk_ext.rs +++ b/src/tools/rust-analyzer/crates/hir-ty/src/chalk_ext.rs @@ -3,8 +3,8 @@ use hir_def::{ItemContainerId, Lookup, TraitId}; use crate::{ - Binders, DynTy, Interner, ProjectionTy, Substitution, TraitRef, Ty, db::HirDatabase, - from_assoc_type_id, from_chalk_trait_id, generics::generics, to_chalk_trait_id, + Interner, ProjectionTy, Substitution, TraitRef, Ty, db::HirDatabase, from_assoc_type_id, + from_chalk_trait_id, generics::generics, to_chalk_trait_id, }; pub(crate) trait ProjectionTyExt { @@ -35,23 +35,6 @@ impl ProjectionTyExt for ProjectionTy { } } -pub(crate) trait DynTyExt { - fn principal(&self) -> Option>>; -} - -impl DynTyExt for DynTy { - fn principal(&self) -> Option>> { - self.bounds.as_ref().filter_map(|bounds| { - bounds.interned().first().and_then(|b| { - b.as_ref().filter_map(|b| match b { - crate::WhereClause::Implemented(trait_ref) => Some(trait_ref), - _ => None, - }) - }) - }) - } -} - pub(crate) trait TraitRefExt { fn hir_trait_id(&self) -> TraitId; } diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/db.rs b/src/tools/rust-analyzer/crates/hir-ty/src/db.rs index 7ad76f35b1f2..a4c19eea162e 100644 --- a/src/tools/rust-analyzer/crates/hir-ty/src/db.rs +++ b/src/tools/rust-analyzer/crates/hir-ty/src/db.rs @@ -17,7 +17,6 @@ use triomphe::Arc; use crate::{ Binders, ImplTraitId, ImplTraits, InferenceResult, TraitEnvironment, Ty, TyDefId, ValueTyDefId, - chalk_db, consteval::ConstEvalError, dyn_compatibility::DynCompatibilityViolation, layout::{Layout, LayoutError}, @@ -308,19 +307,13 @@ pub trait HirDatabase: DefDatabase + std::fmt::Debug { #[salsa::interned] fn intern_coroutine(&self, id: InternedCoroutine) -> InternedCoroutineId; - #[salsa::invoke(chalk_db::fn_def_variance_query)] - fn fn_def_variance(&self, fn_def_id: CallableDefId) -> chalk_db::Variances; - - #[salsa::invoke(chalk_db::adt_variance_query)] - fn adt_variance(&self, adt_id: AdtId) -> chalk_db::Variances; - #[salsa::invoke(crate::variance::variances_of)] #[salsa::cycle( // cycle_fn = crate::variance::variances_of_cycle_fn, // cycle_initial = crate::variance::variances_of_cycle_initial, cycle_result = crate::variance::variances_of_cycle_initial, )] - fn variances_of(&self, def: GenericDefId) -> Option>; + fn variances_of(&self, def: GenericDefId) -> crate::next_solver::VariancesOf<'_>; // next trait solver diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/lib.rs b/src/tools/rust-analyzer/crates/hir-ty/src/lib.rs index 7277617bce8a..77585177c1b5 100644 --- a/src/tools/rust-analyzer/crates/hir-ty/src/lib.rs +++ b/src/tools/rust-analyzer/crates/hir-ty/src/lib.rs @@ -117,7 +117,6 @@ pub use utils::{ TargetFeatureIsSafeInTarget, Unsafety, all_super_traits, direct_super_traits, is_fn_unsafe_to_call, target_feature_is_safe_in_target, }; -pub use variance::Variance; use chalk_ir::{BoundVar, DebruijnIndex, Safety, Scalar}; diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/next_solver/def_id.rs b/src/tools/rust-analyzer/crates/hir-ty/src/next_solver/def_id.rs index 8525d4bc96e6..928e1321e738 100644 --- a/src/tools/rust-analyzer/crates/hir-ty/src/next_solver/def_id.rs +++ b/src/tools/rust-analyzer/crates/hir-ty/src/next_solver/def_id.rs @@ -155,7 +155,7 @@ impl From for SolverDefId { } impl TryFrom for GenericDefId { - type Error = SolverDefId; + type Error = (); fn try_from(value: SolverDefId) -> Result { Ok(match value { @@ -170,7 +170,7 @@ impl TryFrom for GenericDefId { | SolverDefId::InternedCoroutineId(_) | SolverDefId::InternedOpaqueTyId(_) | SolverDefId::EnumVariantId(_) - | SolverDefId::Ctor(_) => return Err(value), + | SolverDefId::Ctor(_) => return Err(()), }) } } diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/next_solver/interner.rs b/src/tools/rust-analyzer/crates/hir-ty/src/next_solver/interner.rs index cfa8b5b8a7f7..7be891106df3 100644 --- a/src/tools/rust-analyzer/crates/hir-ty/src/next_solver/interner.rs +++ b/src/tools/rust-analyzer/crates/hir-ty/src/next_solver/interner.rs @@ -83,7 +83,7 @@ macro_rules! _interned_vec_nolifetime_salsa { ($name:ident, $ty:ty) => { interned_vec_nolifetime_salsa!($name, $ty, nofold); - impl<'db> rustc_type_ir::TypeFoldable> for $name { + impl<'db> rustc_type_ir::TypeFoldable> for $name<'db> { fn try_fold_with>>( self, folder: &mut F, @@ -104,7 +104,7 @@ macro_rules! _interned_vec_nolifetime_salsa { } } - impl<'db> rustc_type_ir::TypeVisitable> for $name { + impl<'db> rustc_type_ir::TypeVisitable> for $name<'db> { fn visit_with>>( &self, visitor: &mut V, @@ -117,14 +117,14 @@ macro_rules! _interned_vec_nolifetime_salsa { } }; ($name:ident, $ty:ty, nofold) => { - #[salsa::interned(no_lifetime, constructor = new_, debug)] + #[salsa::interned(constructor = new_, debug)] pub struct $name { #[returns(ref)] inner_: smallvec::SmallVec<[$ty; 2]>, } - impl $name { - pub fn new_from_iter<'db>( + impl<'db> $name<'db> { + pub fn new_from_iter( interner: DbInterner<'db>, data: impl IntoIterator, ) -> Self { @@ -140,7 +140,7 @@ macro_rules! _interned_vec_nolifetime_salsa { } } - impl rustc_type_ir::inherent::SliceLike for $name { + impl<'db> rustc_type_ir::inherent::SliceLike for $name<'db> { type Item = $ty; type IntoIter = as IntoIterator>::IntoIter; @@ -154,7 +154,7 @@ macro_rules! _interned_vec_nolifetime_salsa { } } - impl IntoIterator for $name { + impl<'db> IntoIterator for $name<'db> { type Item = $ty; type IntoIter = ::IntoIter; @@ -163,7 +163,7 @@ macro_rules! _interned_vec_nolifetime_salsa { } } - impl Default for $name { + impl<'db> Default for $name<'db> { fn default() -> Self { $name::new_from_iter(DbInterner::conjure(), []) } @@ -887,7 +887,7 @@ macro_rules! as_lang_item { impl<'db> rustc_type_ir::Interner for DbInterner<'db> { type DefId = SolverDefId; type LocalDefId = SolverDefId; - type LocalDefIds = SolverDefIds; + type LocalDefIds = SolverDefIds<'db>; type TraitId = TraitIdWrapper; type ForeignId = TypeAliasIdWrapper; type FunctionId = CallableIdWrapper; @@ -904,7 +904,7 @@ impl<'db> rustc_type_ir::Interner for DbInterner<'db> { type Term = Term<'db>; - type BoundVarKinds = BoundVarKinds; + type BoundVarKinds = BoundVarKinds<'db>; type BoundVarKind = BoundVarKind; type PredefinedOpaques = PredefinedOpaques<'db>; @@ -977,7 +977,7 @@ impl<'db> rustc_type_ir::Interner for DbInterner<'db> { type GenericsOf = Generics; - type VariancesOf = VariancesOf; + type VariancesOf = VariancesOf<'db>; type AdtDef = AdtDef; @@ -1045,10 +1045,9 @@ impl<'db> rustc_type_ir::Interner for DbInterner<'db> { fn variances_of(self, def_id: Self::DefId) -> Self::VariancesOf { let generic_def = match def_id { - SolverDefId::FunctionId(def_id) => def_id.into(), - SolverDefId::AdtId(def_id) => def_id.into(), - SolverDefId::Ctor(Ctor::Struct(def_id)) => def_id.into(), - SolverDefId::Ctor(Ctor::Enum(def_id)) => def_id.loc(self.db).parent.into(), + SolverDefId::Ctor(Ctor::Enum(def_id)) | SolverDefId::EnumVariantId(def_id) => { + def_id.loc(self.db).parent.into() + } SolverDefId::InternedOpaqueTyId(_def_id) => { // FIXME(next-solver): track variances // @@ -1059,17 +1058,20 @@ impl<'db> rustc_type_ir::Interner for DbInterner<'db> { (0..self.generics_of(def_id).count()).map(|_| Variance::Invariant), ); } - _ => return VariancesOf::new_from_iter(self, []), + SolverDefId::Ctor(Ctor::Struct(def_id)) => def_id.into(), + SolverDefId::AdtId(def_id) => def_id.into(), + SolverDefId::FunctionId(def_id) => def_id.into(), + SolverDefId::ConstId(_) + | SolverDefId::StaticId(_) + | SolverDefId::TraitId(_) + | SolverDefId::TypeAliasId(_) + | SolverDefId::ImplId(_) + | SolverDefId::InternedClosureId(_) + | SolverDefId::InternedCoroutineId(_) => { + return VariancesOf::new_from_iter(self, []); + } }; - VariancesOf::new_from_iter( - self, - self.db() - .variances_of(generic_def) - .as_deref() - .unwrap_or_default() - .iter() - .map(|v| v.to_nextsolver(self)), - ) + self.db.variances_of(generic_def) } fn type_of(self, def_id: Self::DefId) -> EarlyBinder { diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/next_solver/mapping.rs b/src/tools/rust-analyzer/crates/hir-ty/src/next_solver/mapping.rs index 1a5982cc00d3..adbc6094a221 100644 --- a/src/tools/rust-analyzer/crates/hir-ty/src/next_solver/mapping.rs +++ b/src/tools/rust-analyzer/crates/hir-ty/src/next_solver/mapping.rs @@ -605,8 +605,8 @@ impl<'db, T: NextSolverToChalk<'db, U>, U: HasInterner> } } -impl<'db> ChalkToNextSolver<'db, BoundVarKinds> for chalk_ir::VariableKinds { - fn to_nextsolver(&self, interner: DbInterner<'db>) -> BoundVarKinds { +impl<'db> ChalkToNextSolver<'db, BoundVarKinds<'db>> for chalk_ir::VariableKinds { + fn to_nextsolver(&self, interner: DbInterner<'db>) -> BoundVarKinds<'db> { BoundVarKinds::new_from_iter( interner, self.iter(Interner).map(|v| v.to_nextsolver(interner)), @@ -614,7 +614,7 @@ impl<'db> ChalkToNextSolver<'db, BoundVarKinds> for chalk_ir::VariableKinds NextSolverToChalk<'db, chalk_ir::VariableKinds> for BoundVarKinds { +impl<'db> NextSolverToChalk<'db, chalk_ir::VariableKinds> for BoundVarKinds<'db> { fn to_chalk(self, interner: DbInterner<'db>) -> chalk_ir::VariableKinds { chalk_ir::VariableKinds::from_iter(Interner, self.iter().map(|v| v.to_chalk(interner))) } @@ -763,36 +763,6 @@ impl<'db> ChalkToNextSolver<'db, rustc_ast_ir::Mutability> for chalk_ir::Mutabil } } -impl<'db> ChalkToNextSolver<'db, rustc_type_ir::Variance> for crate::Variance { - fn to_nextsolver(&self, interner: DbInterner<'db>) -> rustc_type_ir::Variance { - match self { - crate::Variance::Covariant => rustc_type_ir::Variance::Covariant, - crate::Variance::Invariant => rustc_type_ir::Variance::Invariant, - crate::Variance::Contravariant => rustc_type_ir::Variance::Contravariant, - crate::Variance::Bivariant => rustc_type_ir::Variance::Bivariant, - } - } -} - -impl<'db> ChalkToNextSolver<'db, rustc_type_ir::Variance> for chalk_ir::Variance { - fn to_nextsolver(&self, interner: DbInterner<'db>) -> rustc_type_ir::Variance { - match self { - chalk_ir::Variance::Covariant => rustc_type_ir::Variance::Covariant, - chalk_ir::Variance::Invariant => rustc_type_ir::Variance::Invariant, - chalk_ir::Variance::Contravariant => rustc_type_ir::Variance::Contravariant, - } - } -} - -impl<'db> ChalkToNextSolver<'db, VariancesOf> for chalk_ir::Variances { - fn to_nextsolver(&self, interner: DbInterner<'db>) -> VariancesOf { - VariancesOf::new_from_iter( - interner, - self.as_slice(Interner).iter().map(|v| v.to_nextsolver(interner)), - ) - } -} - impl<'db> ChalkToNextSolver<'db, Goal, Predicate<'db>>> for chalk_ir::InEnvironment> { diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/variance.rs b/src/tools/rust-analyzer/crates/hir-ty/src/variance.rs index 0ff110106ebe..46898ddeec12 100644 --- a/src/tools/rust-analyzer/crates/hir-ty/src/variance.rs +++ b/src/tools/rust-analyzer/crates/hir-ty/src/variance.rs @@ -13,43 +13,45 @@ //! by the next salsa version. If not, we will likely have to adapt and go with the rustc approach //! while installing firewall per item queries to prevent invalidation issues. -use crate::db::HirDatabase; -use crate::generics::{Generics, generics}; -use crate::next_solver::DbInterner; -use crate::next_solver::mapping::{ChalkToNextSolver, NextSolverToChalk}; -use crate::{ - AliasTy, Const, ConstScalar, DynTyExt, GenericArg, GenericArgData, Interner, Lifetime, - LifetimeData, Ty, TyKind, +use hir_def::{AdtId, GenericDefId, GenericParamId, VariantId, signatures::StructFlags}; +use rustc_ast_ir::Mutability; +use rustc_type_ir::{ + Variance, + inherent::{AdtDef, IntoKind, SliceLike}, }; -use chalk_ir::Mutability; -use hir_def::signatures::StructFlags; -use hir_def::{AdtId, GenericDefId, GenericParamId, VariantId}; -use std::fmt; -use std::ops::Not; use stdx::never; -use triomphe::Arc; -pub(crate) fn variances_of(db: &dyn HirDatabase, def: GenericDefId) -> Option> { +use crate::{ + db::HirDatabase, + generics::{Generics, generics}, + next_solver::{ + Const, ConstKind, DbInterner, ExistentialPredicate, GenericArg, GenericArgs, Region, + RegionKind, Term, Ty, TyKind, VariancesOf, + }, +}; + +pub(crate) fn variances_of(db: &dyn HirDatabase, def: GenericDefId) -> VariancesOf<'_> { tracing::debug!("variances_of(def={:?})", def); + let interner = DbInterner::new_with(db, None, None); match def { GenericDefId::FunctionId(_) => (), GenericDefId::AdtId(adt) => { if let AdtId::StructId(id) = adt { let flags = &db.struct_signature(id).flags; if flags.contains(StructFlags::IS_UNSAFE_CELL) { - return Some(Arc::from_iter(vec![Variance::Invariant; 1])); + return VariancesOf::new_from_iter(interner, [Variance::Invariant]); } else if flags.contains(StructFlags::IS_PHANTOM_DATA) { - return Some(Arc::from_iter(vec![Variance::Covariant; 1])); + return VariancesOf::new_from_iter(interner, [Variance::Covariant]); } } } - _ => return None, + _ => return VariancesOf::new_from_iter(interner, []), } let generics = generics(db, def); let count = generics.len(); if count == 0 { - return None; + return VariancesOf::new_from_iter(interner, []); } let mut variances = Context { generics, variances: vec![Variance::Bivariant; count], db }.solve(); @@ -69,7 +71,7 @@ pub(crate) fn variances_of(db: &dyn HirDatabase, def: GenericDefId) -> Option Option Variance { + // Greatest lower bound of the variance lattice as defined in The Paper: + // + // * + // - + + // o + match (v1, v2) { + (Variance::Invariant, _) | (_, Variance::Invariant) => Variance::Invariant, + + (Variance::Covariant, Variance::Contravariant) => Variance::Invariant, + (Variance::Contravariant, Variance::Covariant) => Variance::Invariant, + + (Variance::Covariant, Variance::Covariant) => Variance::Covariant, + + (Variance::Contravariant, Variance::Contravariant) => Variance::Contravariant, + + (x, Variance::Bivariant) | (Variance::Bivariant, x) => x, + } +} + pub(crate) fn variances_of_cycle_initial( db: &dyn HirDatabase, def: GenericDefId, -) -> Option> { +) -> VariancesOf<'_> { + let interner = DbInterner::new_with(db, None, None); let generics = generics(db, def); let count = generics.len(); - if count == 0 { - return None; - } // FIXME(next-solver): Returns `Invariance` and not `Bivariance` here, see the comment in the main query. - Some(Arc::from(vec![Variance::Invariant; count])) -} - -#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)] -pub enum Variance { - Covariant, // T <: T iff A <: B -- e.g., function return type - Invariant, // T <: T iff B == A -- e.g., type of mutable cell - Contravariant, // T <: T iff B <: A -- e.g., function param type - Bivariant, // T <: T -- e.g., unused type parameter -} - -impl fmt::Display for Variance { - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - match self { - Variance::Covariant => write!(f, "covariant"), - Variance::Invariant => write!(f, "invariant"), - Variance::Contravariant => write!(f, "contravariant"), - Variance::Bivariant => write!(f, "bivariant"), - } - } -} - -impl Variance { - /// `a.xform(b)` combines the variance of a context with the - /// variance of a type with the following meaning. If we are in a - /// context with variance `a`, and we encounter a type argument in - /// a position with variance `b`, then `a.xform(b)` is the new - /// variance with which the argument appears. - /// - /// Example 1: - /// ```ignore (illustrative) - /// *mut Vec - /// ``` - /// Here, the "ambient" variance starts as covariant. `*mut T` is - /// invariant with respect to `T`, so the variance in which the - /// `Vec` appears is `Covariant.xform(Invariant)`, which - /// yields `Invariant`. Now, the type `Vec` is covariant with - /// respect to its type argument `T`, and hence the variance of - /// the `i32` here is `Invariant.xform(Covariant)`, which results - /// (again) in `Invariant`. - /// - /// Example 2: - /// ```ignore (illustrative) - /// fn(*const Vec, *mut Vec` appears is - /// `Contravariant.xform(Covariant)` or `Contravariant`. The same - /// is true for its `i32` argument. In the `*mut T` case, the - /// variance of `Vec` is `Contravariant.xform(Invariant)`, - /// and hence the outermost type is `Invariant` with respect to - /// `Vec` (and its `i32` argument). - /// - /// Source: Figure 1 of "Taming the Wildcards: - /// Combining Definition- and Use-Site Variance" published in PLDI'11. - fn xform(self, v: Variance) -> Variance { - match (self, v) { - // Figure 1, column 1. - (Variance::Covariant, Variance::Covariant) => Variance::Covariant, - (Variance::Covariant, Variance::Contravariant) => Variance::Contravariant, - (Variance::Covariant, Variance::Invariant) => Variance::Invariant, - (Variance::Covariant, Variance::Bivariant) => Variance::Bivariant, - - // Figure 1, column 2. - (Variance::Contravariant, Variance::Covariant) => Variance::Contravariant, - (Variance::Contravariant, Variance::Contravariant) => Variance::Covariant, - (Variance::Contravariant, Variance::Invariant) => Variance::Invariant, - (Variance::Contravariant, Variance::Bivariant) => Variance::Bivariant, - - // Figure 1, column 3. - (Variance::Invariant, _) => Variance::Invariant, - - // Figure 1, column 4. - (Variance::Bivariant, _) => Variance::Bivariant, - } - } - - fn glb(self, v: Variance) -> Variance { - // Greatest lower bound of the variance lattice as - // defined in The Paper: - // - // * - // - + - // o - match (self, v) { - (Variance::Invariant, _) | (_, Variance::Invariant) => Variance::Invariant, - - (Variance::Covariant, Variance::Contravariant) => Variance::Invariant, - (Variance::Contravariant, Variance::Covariant) => Variance::Invariant, - - (Variance::Covariant, Variance::Covariant) => Variance::Covariant, - - (Variance::Contravariant, Variance::Contravariant) => Variance::Contravariant, - - (x, Variance::Bivariant) | (Variance::Bivariant, x) => x, - } - } - - pub fn invariant(self) -> Self { - self.xform(Variance::Invariant) - } - - pub fn covariant(self) -> Self { - self.xform(Variance::Covariant) - } - - pub fn contravariant(self) -> Self { - self.xform(Variance::Contravariant) - } + VariancesOf::new_from_iter(interner, std::iter::repeat_n(Variance::Invariant, count)) } struct Context<'db> { @@ -213,17 +121,16 @@ struct Context<'db> { variances: Vec, } -impl Context<'_> { +impl<'db> Context<'db> { fn solve(mut self) -> Vec { tracing::debug!("solve(generics={:?})", self.generics); match self.generics.def() { GenericDefId::AdtId(adt) => { let db = self.db; let mut add_constraints_from_variant = |variant| { - let subst = self.generics.placeholder_subst(db); - for (_, field) in db.field_types(variant).iter() { + for (_, field) in db.field_types_ns(variant).iter() { self.add_constraints_from_ty( - &field.clone().substitute(Interner, &subst), + field.instantiate_identity(), Variance::Covariant, ); } @@ -239,16 +146,9 @@ impl Context<'_> { } } GenericDefId::FunctionId(f) => { - let subst = self.generics.placeholder_subst(self.db); - let interner = DbInterner::new_with(self.db, None, None); - let args: crate::next_solver::GenericArgs<'_> = subst.to_nextsolver(interner); - let sig = self - .db - .callable_item_signature(f.into()) - .instantiate(interner, args) - .skip_binder() - .to_chalk(interner); - self.add_constraints_from_sig(sig.params_and_return.iter(), Variance::Covariant); + let sig = + self.db.callable_item_signature(f.into()).instantiate_identity().skip_binder(); + self.add_constraints_from_sig(sig.inputs_and_output.iter(), Variance::Covariant); } _ => {} } @@ -276,122 +176,102 @@ impl Context<'_> { /// Adds constraints appropriate for an instance of `ty` appearing /// in a context with the generics defined in `generics` and /// ambient variance `variance` - fn add_constraints_from_ty(&mut self, ty: &Ty, variance: Variance) { + fn add_constraints_from_ty(&mut self, ty: Ty<'db>, variance: Variance) { tracing::debug!("add_constraints_from_ty(ty={:?}, variance={:?})", ty, variance); - match ty.kind(Interner) { - TyKind::Scalar(_) | TyKind::Never | TyKind::Str | TyKind::Foreign(..) => { + match ty.kind() { + TyKind::Int(_) + | TyKind::Uint(_) + | TyKind::Float(_) + | TyKind::Char + | TyKind::Bool + | TyKind::Never + | TyKind::Str + | TyKind::Foreign(..) => { // leaf type -- noop } - TyKind::FnDef(..) | TyKind::Coroutine(..) | TyKind::Closure(..) => { + TyKind::FnDef(..) + | TyKind::Coroutine(..) + | TyKind::CoroutineClosure(..) + | TyKind::Closure(..) => { never!("Unexpected unnameable type in variance computation: {:?}", ty); } - TyKind::Ref(mutbl, lifetime, ty) => { + TyKind::Ref(lifetime, ty, mutbl) => { self.add_constraints_from_region(lifetime, variance); - self.add_constraints_from_mt(ty, *mutbl, variance); + self.add_constraints_from_mt(ty, mutbl, variance); } TyKind::Array(typ, len) => { - self.add_constraints_from_const(len, variance); + self.add_constraints_from_const(len); self.add_constraints_from_ty(typ, variance); } TyKind::Slice(typ) => { self.add_constraints_from_ty(typ, variance); } - TyKind::Raw(mutbl, ty) => { - self.add_constraints_from_mt(ty, *mutbl, variance); + TyKind::RawPtr(ty, mutbl) => { + self.add_constraints_from_mt(ty, mutbl, variance); } - TyKind::Tuple(_, subtys) => { - for subty in subtys.type_parameters(Interner) { - self.add_constraints_from_ty(&subty, variance); + TyKind::Tuple(subtys) => { + for subty in subtys { + self.add_constraints_from_ty(subty, variance); } } TyKind::Adt(def, args) => { - self.add_constraints_from_args(def.0.into(), args.as_slice(Interner), variance); + self.add_constraints_from_args(def.def_id().0.into(), args, variance); } - TyKind::Alias(AliasTy::Opaque(opaque)) => { - self.add_constraints_from_invariant_args( - opaque.substitution.as_slice(Interner), - variance, - ); + TyKind::Alias(_, alias) => { + // FIXME: Probably not correct wrt. opaques. + self.add_constraints_from_invariant_args(alias.args); } - TyKind::Alias(AliasTy::Projection(proj)) => { - self.add_constraints_from_invariant_args( - proj.substitution.as_slice(Interner), - variance, - ); - } - // FIXME: check this - TyKind::AssociatedType(_, subst) => { - self.add_constraints_from_invariant_args(subst.as_slice(Interner), variance); - } - // FIXME: check this - TyKind::OpaqueType(_, subst) => { - self.add_constraints_from_invariant_args(subst.as_slice(Interner), variance); - } - TyKind::Dyn(it) => { + TyKind::Dynamic(bounds, region) => { // The type `dyn Trait +'a` is covariant w/r/t `'a`: - self.add_constraints_from_region(&it.lifetime, variance); + self.add_constraints_from_region(region, variance); - if let Some(trait_ref) = it.principal() { - // Trait are always invariant so we can take advantage of that. - self.add_constraints_from_invariant_args( - trait_ref - .map(|it| it.map(|it| it.substitution.clone())) - .substitute( - Interner, - &[GenericArg::new( - Interner, - chalk_ir::GenericArgData::Ty(TyKind::Error.intern(Interner)), - )], - ) - .skip_binders() - .as_slice(Interner), - variance, - ); + for bound in bounds { + match bound.skip_binder() { + ExistentialPredicate::Trait(trait_ref) => { + self.add_constraints_from_invariant_args(trait_ref.args) + } + ExistentialPredicate::Projection(projection) => { + self.add_constraints_from_invariant_args(projection.args); + match projection.term { + Term::Ty(ty) => { + self.add_constraints_from_ty(ty, Variance::Invariant) + } + Term::Const(konst) => self.add_constraints_from_const(konst), + } + } + ExistentialPredicate::AutoTrait(_) => {} + } } - - // FIXME - // for projection in data.projection_bounds() { - // match projection.skip_binder().term.unpack() { - // TyKind::TermKind::Ty(ty) => { - // self.add_constraints_from_ty( ty, self.invariant); - // } - // TyKind::TermKind::Const(c) => { - // self.add_constraints_from_const( c, self.invariant) - // } - // } - // } } // Chalk has no params, so use placeholders for now? - TyKind::Placeholder(index) => { - let idx = crate::from_placeholder_idx(self.db, *index).0; - let index = self.generics.type_or_const_param_idx(idx).unwrap(); - self.constrain(index, variance); + TyKind::Param(param) => self.constrain(param.index as usize, variance), + TyKind::FnPtr(sig, _) => { + self.add_constraints_from_sig(sig.skip_binder().inputs_and_output.iter(), variance); } - TyKind::Function(f) => { - self.add_constraints_from_sig( - f.substitution.0.iter(Interner).filter_map(move |p| p.ty(Interner)), - variance, - ); - } - TyKind::Error => { + TyKind::Error(_) => { // we encounter this when walking the trait references for object // types, where we use Error as the Self type } - TyKind::CoroutineWitness(..) | TyKind::BoundVar(..) | TyKind::InferenceVar(..) => { + TyKind::Bound(..) => {} + TyKind::CoroutineWitness(..) + | TyKind::Placeholder(..) + | TyKind::Infer(..) + | TyKind::UnsafeBinder(..) + | TyKind::Pat(..) => { never!("unexpected type encountered in variance inference: {:?}", ty) } } } - fn add_constraints_from_invariant_args(&mut self, args: &[GenericArg], variance: Variance) { - let variance_i = variance.invariant(); - - for k in args { - match k.data(Interner) { - GenericArgData::Lifetime(lt) => self.add_constraints_from_region(lt, variance_i), - GenericArgData::Ty(ty) => self.add_constraints_from_ty(ty, variance_i), - GenericArgData::Const(val) => self.add_constraints_from_const(val, variance_i), + fn add_constraints_from_invariant_args(&mut self, args: GenericArgs<'db>) { + for k in args.iter() { + match k { + GenericArg::Lifetime(lt) => { + self.add_constraints_from_region(lt, Variance::Invariant) + } + GenericArg::Ty(ty) => self.add_constraints_from_ty(ty, Variance::Invariant), + GenericArg::Const(val) => self.add_constraints_from_const(val), } } } @@ -401,51 +281,40 @@ impl Context<'_> { fn add_constraints_from_args( &mut self, def_id: GenericDefId, - args: &[GenericArg], + args: GenericArgs<'db>, variance: Variance, ) { - // We don't record `inferred_starts` entries for empty generics. if args.is_empty() { return; } - let Some(variances) = self.db.variances_of(def_id) else { - return; - }; + let variances = self.db.variances_of(def_id); - for (i, k) in args.iter().enumerate() { - match k.data(Interner) { - GenericArgData::Lifetime(lt) => { - self.add_constraints_from_region(lt, variance.xform(variances[i])) - } - GenericArgData::Ty(ty) => { - self.add_constraints_from_ty(ty, variance.xform(variances[i])) - } - GenericArgData::Const(val) => self.add_constraints_from_const(val, variance), + for (k, v) in args.iter().zip(variances) { + match k { + GenericArg::Lifetime(lt) => self.add_constraints_from_region(lt, variance.xform(v)), + GenericArg::Ty(ty) => self.add_constraints_from_ty(ty, variance.xform(v)), + GenericArg::Const(val) => self.add_constraints_from_const(val), } } } /// Adds constraints appropriate for a const expression `val` /// in a context with ambient variance `variance` - fn add_constraints_from_const(&mut self, c: &Const, variance: Variance) { - match &c.data(Interner).value { - chalk_ir::ConstValue::Concrete(c) => { - if let ConstScalar::UnevaluatedConst(_, subst) = &c.interned { - self.add_constraints_from_invariant_args(subst.as_slice(Interner), variance); - } - } + fn add_constraints_from_const(&mut self, c: Const<'db>) { + match c.kind() { + ConstKind::Unevaluated(c) => self.add_constraints_from_invariant_args(c.args), _ => {} } } /// Adds constraints appropriate for a function with signature /// `sig` appearing in a context with ambient variance `variance` - fn add_constraints_from_sig<'a>( + fn add_constraints_from_sig( &mut self, - mut sig_tys: impl DoubleEndedIterator, + mut sig_tys: impl DoubleEndedIterator>, variance: Variance, ) { - let contra = variance.contravariant(); + let contra = variance.xform(Variance::Contravariant); let Some(output) = sig_tys.next_back() else { return never!("function signature has no return type"); }; @@ -457,27 +326,26 @@ impl Context<'_> { /// Adds constraints appropriate for a region appearing in a /// context with ambient variance `variance` - fn add_constraints_from_region(&mut self, region: &Lifetime, variance: Variance) { + fn add_constraints_from_region(&mut self, region: Region<'db>, variance: Variance) { tracing::debug!( "add_constraints_from_region(region={:?}, variance={:?})", region, variance ); - match region.data(Interner) { - LifetimeData::Placeholder(index) => { - let idx = crate::lt_from_placeholder_idx(self.db, *index).0; - let inferred = self.generics.lifetime_idx(idx).unwrap(); - self.constrain(inferred, variance); - } - LifetimeData::Static => {} - LifetimeData::BoundVar(..) => { + match region.kind() { + RegionKind::ReEarlyParam(param) => self.constrain(param.index as usize, variance), + RegionKind::ReStatic => {} + RegionKind::ReBound(..) => { // Either a higher-ranked region inside of a type or a // late-bound function parameter. // // We do not compute constraints for either of these. } - LifetimeData::Error => {} - LifetimeData::Phantom(..) | LifetimeData::InferenceVar(..) | LifetimeData::Erased => { + RegionKind::ReError(_) => {} + RegionKind::ReLateParam(..) + | RegionKind::RePlaceholder(..) + | RegionKind::ReVar(..) + | RegionKind::ReErased => { // We don't expect to see anything but 'static or bound // regions when visiting member types or method types. never!( @@ -491,11 +359,11 @@ impl Context<'_> { /// Adds constraints appropriate for a mutability-type pair /// appearing in a context with ambient variance `variance` - fn add_constraints_from_mt(&mut self, ty: &Ty, mt: Mutability, variance: Variance) { + fn add_constraints_from_mt(&mut self, ty: Ty<'db>, mt: Mutability, variance: Variance) { self.add_constraints_from_ty( ty, match mt { - Mutability::Mut => variance.invariant(), + Mutability::Mut => Variance::Invariant, Mutability::Not => variance, }, ); @@ -508,7 +376,7 @@ impl Context<'_> { self.variances[index], variance ); - self.variances[index] = self.variances[index].glb(variance); + self.variances[index] = glb(self.variances[index], variance); } } @@ -519,6 +387,7 @@ mod tests { AdtId, GenericDefId, ModuleDefId, hir::generics::GenericParamDataRef, src::HasSource, }; use itertools::Itertools; + use rustc_type_ir::{Variance, inherent::SliceLike}; use stdx::format_to; use syntax::{AstNode, ast::HasName}; use test_fixture::WithFixture; @@ -1037,26 +906,21 @@ struct FixedPoint(&'static FixedPoint<(), T, U>, V); let loc = it.lookup(&db); loc.source(&db).value.name().unwrap() } - GenericDefId::TraitId(it) => { - let loc = it.lookup(&db); - loc.source(&db).value.name().unwrap() - } - GenericDefId::TypeAliasId(it) => { - let loc = it.lookup(&db); - loc.source(&db).value.name().unwrap() - } - GenericDefId::ImplId(_) => return None, - GenericDefId::ConstId(_) => return None, - GenericDefId::StaticId(_) => return None, + GenericDefId::TraitId(_) + | GenericDefId::TypeAliasId(_) + | GenericDefId::ImplId(_) + | GenericDefId::ConstId(_) + | GenericDefId::StaticId(_) => return None, }, )) }) .sorted_by_key(|(_, n)| n.syntax().text_range().start()); let mut res = String::new(); for (def, name) in defs { - let Some(variances) = db.variances_of(def) else { + let variances = db.variances_of(def); + if variances.is_empty() { continue; - }; + } format_to!( res, "{name}[{}]\n", @@ -1072,10 +936,16 @@ struct FixedPoint(&'static FixedPoint<(), T, U>, V); &lifetime_param_data.name } }) - .zip_eq(&*variances) + .zip_eq(variances) .format_with(", ", |(name, var), f| f(&format_args!( - "{}: {var}", - name.as_str() + "{}: {}", + name.as_str(), + match var { + Variance::Covariant => "covariant", + Variance::Invariant => "invariant", + Variance::Contravariant => "contravariant", + Variance::Bivariant => "bivariant", + }, ))) ); } diff --git a/src/tools/rust-analyzer/crates/hir/src/lib.rs b/src/tools/rust-analyzer/crates/hir/src/lib.rs index fc516a6764a5..36c8c3051cf5 100644 --- a/src/tools/rust-analyzer/crates/hir/src/lib.rs +++ b/src/tools/rust-analyzer/crates/hir/src/lib.rs @@ -36,6 +36,7 @@ pub mod term_search; mod display; use std::{ + fmt, mem::discriminant, ops::{ControlFlow, Not}, }; @@ -160,7 +161,7 @@ pub use { // FIXME: Properly encapsulate mir hir_ty::mir, hir_ty::{ - CastError, FnAbi, PointerCast, Variance, attach_db, attach_db_allow_change, + CastError, FnAbi, PointerCast, attach_db, attach_db_allow_change, consteval::ConstEvalError, diagnostics::UnsafetyReason, display::{ClosureStyle, DisplayTarget, HirDisplay, HirDisplayError, HirWrite}, @@ -4110,7 +4111,39 @@ impl GenericParam { GenericParam::ConstParam(_) => return None, GenericParam::LifetimeParam(it) => generics.lifetime_idx(it.id)?, }; - db.variances_of(parent)?.get(index).copied() + db.variances_of(parent).get(index).map(Into::into) + } +} + +#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)] +pub enum Variance { + Bivariant, + Covariant, + Contravariant, + Invariant, +} + +impl From for Variance { + #[inline] + fn from(value: rustc_type_ir::Variance) -> Self { + match value { + rustc_type_ir::Variance::Covariant => Variance::Covariant, + rustc_type_ir::Variance::Invariant => Variance::Invariant, + rustc_type_ir::Variance::Contravariant => Variance::Contravariant, + rustc_type_ir::Variance::Bivariant => Variance::Bivariant, + } + } +} + +impl fmt::Display for Variance { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + let description = match self { + Variance::Bivariant => "bivariant", + Variance::Covariant => "covariant", + Variance::Contravariant => "contravariant", + Variance::Invariant => "invariant", + }; + f.pad(description) } }