Merge #8445

8445: `hir_ty` cleanup r=flodiebold a=flodiebold

Move lots of things around within `hir_ty`. Most notably, all the Chalk-related stuff moves from within `traits/` to the top-level, since Chalk isn't purely a "traits thing" anymore.

Co-authored-by: Florian Diebold <[email protected]>

Author: bors[bot]

crates/hir_ty/src/chalk_cast.rs

@@ -1,50 +1,47 @@
-//! Conversion code from/to Chalk.
+//! The implementation of `RustIrDatabase` for Chalk, which provides information
+//! about the code that Chalk needs.
 use std::sync::Arc;
 
 use log::debug;
 
-use chalk_ir::{fold::shift::Shift, CanonicalVarKinds};
+use chalk_ir::{cast::Cast, fold::shift::Shift, CanonicalVarKinds};
 use chalk_solve::rust_ir::{self, OpaqueTyDatumBound, WellKnownTrait};
 
-use base_db::{salsa::InternKey, CrateId};
+use base_db::CrateId;
 use hir_def::{
     lang_item::{lang_attr, LangItemTarget},
-    AssocContainerId, AssocItemId, HasModule, Lookup, TypeAliasId,
+    AssocContainerId, AssocItemId, GenericDefId, HasModule, Lookup, TypeAliasId,
 };
 use hir_expand::name::name;
 
-use super::ChalkContext;
 use crate::{
     db::HirDatabase,
     display::HirDisplay,
-    from_assoc_type_id, make_only_type_binders,
+    from_assoc_type_id, from_chalk_trait_id, make_only_type_binders,
+    mapping::{from_chalk, ToChalk, TypeAliasAsValue},
     method_resolution::{TyFingerprint, ALL_FLOAT_FPS, ALL_INT_FPS},
     to_assoc_type_id, to_chalk_trait_id,
+    traits::ChalkContext,
     utils::generics,
-    AliasEq, AliasTy, BoundVar, CallableDefId, DebruijnIndex, FnDefId, ProjectionTy, Substitution,
-    TraitRef, TraitRefExt, Ty, TyBuilder, TyExt, TyKind, WhereClause,
+    AliasEq, AliasTy, BoundVar, CallableDefId, DebruijnIndex, FnDefId, Interner, ProjectionTy,
+    ProjectionTyExt, QuantifiedWhereClause, Substitution, TraitRef, TraitRefExt, Ty, TyBuilder,
+    TyExt, TyKind, WhereClause,
 };
-use mapping::{convert_where_clauses, generic_predicate_to_inline_bound, TypeAliasAsValue};
 
-pub use self::interner::Interner;
-pub(crate) use self::interner::*;
-
-pub(super) mod tls;
-mod interner;
-mod mapping;
-
-pub(crate) trait ToChalk {
-    type Chalk;
-    fn to_chalk(self, db: &dyn HirDatabase) -> Self::Chalk;
-    fn from_chalk(db: &dyn HirDatabase, chalk: Self::Chalk) -> Self;
-}
-
-pub(crate) fn from_chalk<T, ChalkT>(db: &dyn HirDatabase, chalk: ChalkT) -> T
-where
-    T: ToChalk<Chalk = ChalkT>,
-{
-    T::from_chalk(db, chalk)
-}
+pub(crate) type AssociatedTyDatum = chalk_solve::rust_ir::AssociatedTyDatum<Interner>;
+pub(crate) type TraitDatum = chalk_solve::rust_ir::TraitDatum<Interner>;
+pub(crate) type StructDatum = chalk_solve::rust_ir::AdtDatum<Interner>;
+pub(crate) type ImplDatum = chalk_solve::rust_ir::ImplDatum<Interner>;
+pub(crate) type OpaqueTyDatum = chalk_solve::rust_ir::OpaqueTyDatum<Interner>;
+
+pub(crate) type AssocTypeId = chalk_ir::AssocTypeId<Interner>;
+pub(crate) type TraitId = chalk_ir::TraitId<Interner>;
+pub(crate) type AdtId = chalk_ir::AdtId<Interner>;
+pub(crate) type ImplId = chalk_ir::ImplId<Interner>;
+pub(crate) type AssociatedTyValueId = chalk_solve::rust_ir::AssociatedTyValueId<Interner>;
+pub(crate) type AssociatedTyValue = chalk_solve::rust_ir::AssociatedTyValue<Interner>;
+pub(crate) type FnDefDatum = chalk_solve::rust_ir::FnDefDatum<Interner>;
+pub(crate) type Variances = chalk_ir::Variances<Interner>;
 
 impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
     fn associated_ty_data(&self, id: AssocTypeId) -> Arc<AssociatedTyDatum> {
@@ -82,7 +79,7 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
         binders: &CanonicalVarKinds<Interner>,
     ) -> Vec<ImplId> {
         debug!("impls_for_trait {:?}", trait_id);
-        let trait_: hir_def::TraitId = from_chalk(self.db, trait_id);
+        let trait_: hir_def::TraitId = from_chalk_trait_id(trait_id);
 
         let ty: Ty = parameters[0].assert_ty_ref(&Interner).clone();
 
@@ -164,7 +161,7 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
             Some(LangItemTarget::TraitId(trait_)) => trait_,
             _ => return None,
         };
-        Some(trait_.to_chalk(self.db))
+        Some(to_chalk_trait_id(trait_))
     }
 
     fn program_clauses_for_env(
@@ -311,7 +308,7 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
     }
 
     fn trait_name(&self, trait_id: chalk_ir::TraitId<Interner>) -> String {
-        let id = from_chalk(self.db, trait_id);
+        let id = from_chalk_trait_id(trait_id);
         self.db.trait_data(id).name.to_string()
     }
     fn adt_name(&self, chalk_ir::AdtId(adt_id): AdtId) -> String {
@@ -416,7 +413,7 @@ pub(crate) fn trait_datum_query(
     trait_id: TraitId,
 ) -> Arc<TraitDatum> {
     debug!("trait_datum {:?}", trait_id);
-    let trait_: hir_def::TraitId = from_chalk(db, trait_id);
+    let trait_ = from_chalk_trait_id(trait_id);
     let trait_data = db.trait_data(trait_);
     debug!("trait {:?} = {:?}", trait_id, trait_data.name);
     let generic_params = generics(db.upcast(), trait_.into());
@@ -679,38 +676,65 @@ pub(crate) fn adt_variance_query(
     )
 }
 
-impl From<FnDefId> for crate::db::InternedCallableDefId {
-    fn from(fn_def_id: FnDefId) -> Self {
-        InternKey::from_intern_id(fn_def_id.0)
-    }
-}
-
-impl From<crate::db::InternedCallableDefId> for FnDefId {
-    fn from(callable_def_id: crate::db::InternedCallableDefId) -> Self {
-        chalk_ir::FnDefId(callable_def_id.as_intern_id())
-    }
-}
-
-impl From<OpaqueTyId> for crate::db::InternedOpaqueTyId {
-    fn from(id: OpaqueTyId) -> Self {
-        InternKey::from_intern_id(id.0)
-    }
-}
-
-impl From<crate::db::InternedOpaqueTyId> for OpaqueTyId {
-    fn from(id: crate::db::InternedOpaqueTyId) -> Self {
-        chalk_ir::OpaqueTyId(id.as_intern_id())
-    }
-}
-
-impl From<chalk_ir::ClosureId<Interner>> for crate::db::InternedClosureId {
-    fn from(id: chalk_ir::ClosureId<Interner>) -> Self {
-        Self::from_intern_id(id.0)
-    }
+pub(super) fn convert_where_clauses(
+    db: &dyn HirDatabase,
+    def: GenericDefId,
+    substs: &Substitution,
+) -> Vec<chalk_ir::QuantifiedWhereClause<Interner>> {
+    let generic_predicates = db.generic_predicates(def);
+    let mut result = Vec::with_capacity(generic_predicates.len());
+    for pred in generic_predicates.iter() {
+        result.push(pred.clone().substitute(&Interner, substs));
+    }
+    result
 }
 
-impl From<crate::db::InternedClosureId> for chalk_ir::ClosureId<Interner> {
-    fn from(id: crate::db::InternedClosureId) -> Self {
-        chalk_ir::ClosureId(id.as_intern_id())
+pub(super) fn generic_predicate_to_inline_bound(
+    db: &dyn HirDatabase,
+    pred: &QuantifiedWhereClause,
+    self_ty: &Ty,
+) -> Option<chalk_ir::Binders<rust_ir::InlineBound<Interner>>> {
+    // An InlineBound is like a GenericPredicate, except the self type is left out.
+    // We don't have a special type for this, but Chalk does.
+    let self_ty_shifted_in = self_ty.clone().shifted_in_from(&Interner, DebruijnIndex::ONE);
+    let (pred, binders) = pred.as_ref().into_value_and_skipped_binders();
+    match pred {
+        WhereClause::Implemented(trait_ref) => {
+            if trait_ref.self_type_parameter(&Interner) != self_ty_shifted_in {
+                // we can only convert predicates back to type bounds if they
+                // have the expected self type
+                return None;
+            }
+            let args_no_self = trait_ref.substitution.as_slice(&Interner)[1..]
+                .iter()
+                .map(|ty| ty.clone().cast(&Interner))
+                .collect();
+            let trait_bound = rust_ir::TraitBound { trait_id: trait_ref.trait_id, args_no_self };
+            Some(chalk_ir::Binders::new(binders, rust_ir::InlineBound::TraitBound(trait_bound)))
+        }
+        WhereClause::AliasEq(AliasEq { alias: AliasTy::Projection(projection_ty), ty }) => {
+            if projection_ty.self_type_parameter(&Interner) != self_ty_shifted_in {
+                return None;
+            }
+            let trait_ = projection_ty.trait_(db);
+            let args_no_self = projection_ty.substitution.as_slice(&Interner)[1..]
+                .iter()
+                .map(|ty| ty.clone().cast(&Interner))
+                .collect();
+            let alias_eq_bound = rust_ir::AliasEqBound {
+                value: ty.clone(),
+                trait_bound: rust_ir::TraitBound {
+                    trait_id: to_chalk_trait_id(trait_),
+                    args_no_self,
+                },
+                associated_ty_id: projection_ty.associated_ty_id,
+                parameters: Vec::new(), // FIXME we don't support generic associated types yet
+            };
+            Some(chalk_ir::Binders::new(
+                binders,
+                rust_ir::InlineBound::AliasEqBound(alias_eq_bound),
+            ))
+        }
+        _ => None,
     }
 }

crates/hir_ty/src/traits/chalk.rs renamed to crates/hir_ty/src/chalk_db.rs

@@ -1,4 +1,5 @@
-//! FIXME: write short doc here
+//! The home of `HirDatabase`, which is the Salsa database containing all the
+//! type inference-related queries.
 
 use std::sync::Arc;
 
@@ -10,9 +11,9 @@ use hir_def::{
 use la_arena::ArenaMap;
 
 use crate::{
+    chalk_db,
     method_resolution::{InherentImpls, TraitImpls},
-    traits::chalk,
-    Binders, CallableDefId, FnDefId, ImplTraitId, InferenceResult, PolyFnSig,
+    Binders, CallableDefId, FnDefId, ImplTraitId, InferenceResult, Interner, PolyFnSig,
     QuantifiedWhereClause, ReturnTypeImplTraits, TraitRef, Ty, TyDefId, ValueTyDefId,
 };
 use hir_expand::name::Name;
@@ -94,33 +95,38 @@ pub trait HirDatabase: DefDatabase + Upcast<dyn DefDatabase> {
     #[salsa::interned]
     fn intern_closure(&self, id: (DefWithBodyId, ExprId)) -> InternedClosureId;
 
-    #[salsa::invoke(chalk::associated_ty_data_query)]
-    fn associated_ty_data(&self, id: chalk::AssocTypeId) -> Arc<chalk::AssociatedTyDatum>;
+    #[salsa::invoke(chalk_db::associated_ty_data_query)]
+    fn associated_ty_data(&self, id: chalk_db::AssocTypeId) -> Arc<chalk_db::AssociatedTyDatum>;
 
-    #[salsa::invoke(chalk::trait_datum_query)]
-    fn trait_datum(&self, krate: CrateId, trait_id: chalk::TraitId) -> Arc<chalk::TraitDatum>;
+    #[salsa::invoke(chalk_db::trait_datum_query)]
+    fn trait_datum(&self, krate: CrateId, trait_id: chalk_db::TraitId)
+        -> Arc<chalk_db::TraitDatum>;
 
-    #[salsa::invoke(chalk::struct_datum_query)]
-    fn struct_datum(&self, krate: CrateId, struct_id: chalk::AdtId) -> Arc<chalk::StructDatum>;
+    #[salsa::invoke(chalk_db::struct_datum_query)]
+    fn struct_datum(
+        &self,
+        krate: CrateId,
+        struct_id: chalk_db::AdtId,
+    ) -> Arc<chalk_db::StructDatum>;
 
-    #[salsa::invoke(crate::traits::chalk::impl_datum_query)]
-    fn impl_datum(&self, krate: CrateId, impl_id: chalk::ImplId) -> Arc<chalk::ImplDatum>;
+    #[salsa::invoke(chalk_db::impl_datum_query)]
+    fn impl_datum(&self, krate: CrateId, impl_id: chalk_db::ImplId) -> Arc<chalk_db::ImplDatum>;
 
-    #[salsa::invoke(crate::traits::chalk::fn_def_datum_query)]
-    fn fn_def_datum(&self, krate: CrateId, fn_def_id: FnDefId) -> Arc<chalk::FnDefDatum>;
+    #[salsa::invoke(chalk_db::fn_def_datum_query)]
+    fn fn_def_datum(&self, krate: CrateId, fn_def_id: FnDefId) -> Arc<chalk_db::FnDefDatum>;
 
-    #[salsa::invoke(crate::traits::chalk::fn_def_variance_query)]
-    fn fn_def_variance(&self, krate: CrateId, fn_def_id: FnDefId) -> chalk::Variances;
+    #[salsa::invoke(chalk_db::fn_def_variance_query)]
+    fn fn_def_variance(&self, krate: CrateId, fn_def_id: FnDefId) -> chalk_db::Variances;
 
-    #[salsa::invoke(crate::traits::chalk::adt_variance_query)]
-    fn adt_variance(&self, krate: CrateId, adt_id: chalk::AdtId) -> chalk::Variances;
+    #[salsa::invoke(chalk_db::adt_variance_query)]
+    fn adt_variance(&self, krate: CrateId, adt_id: chalk_db::AdtId) -> chalk_db::Variances;
 
-    #[salsa::invoke(crate::traits::chalk::associated_ty_value_query)]
+    #[salsa::invoke(chalk_db::associated_ty_value_query)]
     fn associated_ty_value(
         &self,
         krate: CrateId,
-        id: chalk::AssociatedTyValueId,
-    ) -> Arc<chalk::AssociatedTyValue>;
+        id: chalk_db::AssociatedTyValueId,
+    ) -> Arc<chalk_db::AssociatedTyValue>;
 
     #[salsa::invoke(crate::traits::trait_solve_query)]
     fn trait_solve(
@@ -129,12 +135,12 @@ pub trait HirDatabase: DefDatabase + Upcast<dyn DefDatabase> {
         goal: crate::Canonical<crate::InEnvironment<crate::DomainGoal>>,
     ) -> Option<crate::Solution>;
 
-    #[salsa::invoke(crate::traits::chalk::program_clauses_for_chalk_env_query)]
+    #[salsa::invoke(chalk_db::program_clauses_for_chalk_env_query)]
     fn program_clauses_for_chalk_env(
         &self,
         krate: CrateId,
-        env: chalk_ir::Environment<chalk::Interner>,
-    ) -> chalk_ir::ProgramClauses<chalk::Interner>;
+        env: chalk_ir::Environment<Interner>,
+    ) -> chalk_ir::ProgramClauses<Interner>;
 }
 
 fn infer_wait(db: &dyn HirDatabase, def: DefWithBodyId) -> Arc<InferenceResult> {

crates/hir_ty/src/db.rs

@@ -1,4 +1,4 @@
-//! FIXME: write short doc here
+//! Type inference-based diagnostics.
 mod expr;
 mod match_check;
 mod unsafe_check;

crates/hir_ty/src/diagnostics.rs

@@ -1,4 +1,6 @@
-//! FIXME: write short doc here
+//! The `HirDisplay` trait, which serves two purposes: Turning various bits from
+//! HIR back into source code, and just displaying them for debugging/testing
+//! purposes.
 
 use std::{
     array,
@@ -20,11 +22,11 @@ use hir_expand::name::Name;
 
 use crate::{
     const_from_placeholder_idx, db::HirDatabase, from_assoc_type_id, from_foreign_def_id,
-    from_placeholder_idx, lt_from_placeholder_idx, primitive, subst_prefix, to_assoc_type_id,
-    traits::chalk::from_chalk, utils::generics, AdtId, AliasEq, AliasTy, CallableDefId,
-    CallableSig, Const, ConstValue, DomainGoal, GenericArg, ImplTraitId, Interner, Lifetime,
-    LifetimeData, LifetimeOutlives, Mutability, OpaqueTy, ProjectionTy, ProjectionTyExt,
-    QuantifiedWhereClause, Scalar, TraitRef, TraitRefExt, Ty, TyExt, TyKind, WhereClause,
+    from_placeholder_idx, lt_from_placeholder_idx, mapping::from_chalk, primitive, subst_prefix,
+    to_assoc_type_id, utils::generics, AdtId, AliasEq, AliasTy, CallableDefId, CallableSig, Const,
+    ConstValue, DomainGoal, GenericArg, ImplTraitId, Interner, Lifetime, LifetimeData,
+    LifetimeOutlives, Mutability, OpaqueTy, ProjectionTy, ProjectionTyExt, QuantifiedWhereClause,
+    Scalar, TraitRef, TraitRefExt, Ty, TyExt, TyKind, WhereClause,
 };
 
 pub struct HirFormatter<'a> {

crates/hir_ty/src/display.rs

@@ -17,10 +17,11 @@ use syntax::ast::RangeOp;
 use crate::{
     autoderef, dummy_usize_const,
     lower::lower_to_chalk_mutability,
+    mapping::from_chalk,
     method_resolution, op,
     primitive::{self, UintTy},
     static_lifetime, to_chalk_trait_id,
-    traits::{chalk::from_chalk, FnTrait},
+    traits::FnTrait,
     utils::{generics, Generics},
     AdtId, Binders, CallableDefId, FnPointer, FnSig, FnSubst, InEnvironment, Interner,
     ProjectionTyExt, Rawness, Scalar, Substitution, TraitRef, Ty, TyBuilder, TyExt, TyKind,