Search more efficiently for int/float impls

3 files changed, 118 insertions, 18 deletions

diff --git a/crates/ra_hir_ty/src/method_resolution.rs b/crates/ra_hir_ty/src/method_resolution.rs
index a45febbf7..fb4b30a13 100644
--- a/crates/ra_hir_ty/src/method_resolution.rs
+++ b/crates/ra_hir_ty/src/method_resolution.rs
@@ -6,8 +6,10 @@ use std::{iter, sync::Arc};
 
 use arrayvec::ArrayVec;
 use hir_def::{
-    lang_item::LangItemTarget, type_ref::Mutability, AssocContainerId, AssocItemId, FunctionId,
-    HasModule, ImplId, Lookup, TraitId,
+    builtin_type::{IntBitness, Signedness},
+    lang_item::LangItemTarget,
+    type_ref::Mutability,
+    AssocContainerId, AssocItemId, FunctionId, HasModule, ImplId, Lookup, TraitId,
 };
 use hir_expand::name::Name;
 use ra_db::CrateId;
@@ -16,9 +18,12 @@ use rustc_hash::{FxHashMap, FxHashSet};
 
 use super::Substs;
 use crate::{
-    autoderef, db::HirDatabase, primitive::FloatBitness, utils::all_super_traits, ApplicationTy,
-    Canonical, DebruijnIndex, InEnvironment, TraitEnvironment, TraitRef, Ty, TyKind, TypeCtor,
-    TypeWalk,
+    autoderef,
+    db::HirDatabase,
+    primitive::{FloatBitness, FloatTy, IntTy},
+    utils::all_super_traits,
+    ApplicationTy, Canonical, DebruijnIndex, InEnvironment, TraitEnvironment, TraitRef, Ty, TyKind,
+    TypeCtor, TypeWalk,
 };
 
 /// This is used as a key for indexing impls.
@@ -39,6 +44,62 @@ impl TyFingerprint {
     }
 }
 
+pub(crate) const ALL_INT_FPS: [TyFingerprint; 12] = [
+    TyFingerprint::Apply(TypeCtor::Int(IntTy {
+        signedness: Signedness::Unsigned,
+        bitness: IntBitness::X8,
+    })),
+    TyFingerprint::Apply(TypeCtor::Int(IntTy {
+        signedness: Signedness::Unsigned,
+        bitness: IntBitness::X16,
+    })),
+    TyFingerprint::Apply(TypeCtor::Int(IntTy {
+        signedness: Signedness::Unsigned,
+        bitness: IntBitness::X32,
+    })),
+    TyFingerprint::Apply(TypeCtor::Int(IntTy {
+        signedness: Signedness::Unsigned,
+        bitness: IntBitness::X64,
+    })),
+    TyFingerprint::Apply(TypeCtor::Int(IntTy {
+        signedness: Signedness::Unsigned,
+        bitness: IntBitness::X128,
+    })),
+    TyFingerprint::Apply(TypeCtor::Int(IntTy {
+        signedness: Signedness::Unsigned,
+        bitness: IntBitness::Xsize,
+    })),
+    TyFingerprint::Apply(TypeCtor::Int(IntTy {
+        signedness: Signedness::Signed,
+        bitness: IntBitness::X8,
+    })),
+    TyFingerprint::Apply(TypeCtor::Int(IntTy {
+        signedness: Signedness::Signed,
+        bitness: IntBitness::X16,
+    })),
+    TyFingerprint::Apply(TypeCtor::Int(IntTy {
+        signedness: Signedness::Signed,
+        bitness: IntBitness::X32,
+    })),
+    TyFingerprint::Apply(TypeCtor::Int(IntTy {
+        signedness: Signedness::Signed,
+        bitness: IntBitness::X64,
+    })),
+    TyFingerprint::Apply(TypeCtor::Int(IntTy {
+        signedness: Signedness::Signed,
+        bitness: IntBitness::X128,
+    })),
+    TyFingerprint::Apply(TypeCtor::Int(IntTy {
+        signedness: Signedness::Signed,
+        bitness: IntBitness::Xsize,
+    })),
+];
+
+pub(crate) const ALL_FLOAT_FPS: [TyFingerprint; 2] = [
+    TyFingerprint::Apply(TypeCtor::Float(FloatTy { bitness: FloatBitness::X32 })),
+    TyFingerprint::Apply(TypeCtor::Float(FloatTy { bitness: FloatBitness::X64 })),
+];
+
 /// Trait impls defined or available in some crate.
 #[derive(Debug, Eq, PartialEq)]
 pub struct TraitImpls {
diff --git a/crates/ra_hir_ty/src/tests/traits.rs b/crates/ra_hir_ty/src/tests/traits.rs
index 85bcd0050..511ed8fe3 100644
--- a/crates/ra_hir_ty/src/tests/traits.rs
+++ b/crates/ra_hir_ty/src/tests/traits.rs
@@ -3042,7 +3042,7 @@ fn foo() {
 }
 
 #[test]
-fn variable_kinds() {
+fn variable_kinds_1() {
     check_types(
         r#"
 trait Trait<T> { fn get(self, t: T) -> T; }
@@ -3058,3 +3058,20 @@ fn test() {
         "#,
     );
 }
+
+#[test]
+fn variable_kinds_2() {
+    check_types(
+        r#"
+trait Trait { fn get(self) -> Self; }
+impl Trait for u128 {}
+impl Trait for f32 {}
+fn test() {
+    1.get();
+  //^^^^^^^ u128
+    (1.).get();
+  //^^^^^^^^^^ f32
+}
+        "#,
+    );
+}
diff --git a/crates/ra_hir_ty/src/traits/chalk.rs b/crates/ra_hir_ty/src/traits/chalk.rs
index e944c1976..c448aea65 100644
--- a/crates/ra_hir_ty/src/traits/chalk.rs
+++ b/crates/ra_hir_ty/src/traits/chalk.rs
@@ -14,7 +14,10 @@ use ra_db::{salsa::InternKey, CrateId};
 
 use super::{builtin, AssocTyValue, ChalkContext, Impl};
 use crate::{
-    db::HirDatabase, display::HirDisplay, method_resolution::TyFingerprint, utils::generics,
+    db::HirDatabase,
+    display::HirDisplay,
+    method_resolution::{TyFingerprint, ALL_FLOAT_FPS, ALL_INT_FPS},
+    utils::generics,
     CallableDef, DebruijnIndex, GenericPredicate, Substs, Ty, TypeCtor,
 };
 use mapping::{convert_where_clauses, generic_predicate_to_inline_bound, make_binders};
@@ -66,16 +69,31 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
         &self,
         trait_id: TraitId,
         parameters: &[GenericArg<Interner>],
-        _binders: &CanonicalVarKinds<Interner>,
+        binders: &CanonicalVarKinds<Interner>,
     ) -> Vec<ImplId> {
         debug!("impls_for_trait {:?}", trait_id);
         let trait_: hir_def::TraitId = from_chalk(self.db, trait_id);
 
-        // FIXME use binders to look for int/float impls when necessary
-
         let ty: Ty = from_chalk(self.db, parameters[0].assert_ty_ref(&Interner).clone());
 
+        fn binder_kind(ty: &Ty, binders: &CanonicalVarKinds<Interner>) -> Option<chalk_ir::TyKind> {
+            if let Ty::Bound(bv) = ty {
+                let binders = binders.as_slice(&Interner);
+                if bv.debruijn == DebruijnIndex::INNERMOST {
+                    if let chalk_ir::VariableKind::Ty(tk) = binders[bv.index].kind {
+                        return Some(tk);
+                    }
+                }
+            }
+            None
+        }
+
         let self_ty_fp = TyFingerprint::for_impl(&ty);
+        let fps: &[TyFingerprint] = match binder_kind(&ty, binders) {
+            Some(chalk_ir::TyKind::Integer) => &ALL_INT_FPS,
+            Some(chalk_ir::TyKind::Float) => &ALL_FLOAT_FPS,
+            _ => self_ty_fp.as_ref().map(std::slice::from_ref).unwrap_or(&[]),
+        };
 
         // Note: Since we're using impls_for_trait, only impls where the trait
         // can be resolved should ever reach Chalk. `impl_datum` relies on that
@@ -86,17 +104,21 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
 
         let id_to_chalk = |id: hir_def::ImplId| Impl::ImplDef(id).to_chalk(self.db);
 
-        let mut result: Vec<_> = match self_ty_fp {
-            Some(fp) => impl_maps
+        let mut result: Vec<_> = if fps.is_empty() {
+            debug!("Unrestricted search for {:?} impls...", trait_);
+            impl_maps
+                .iter()
+                .flat_map(|crate_impl_defs| crate_impl_defs.for_trait(trait_).map(id_to_chalk))
+                .collect()
+        } else {
+            impl_maps
                 .iter()
                 .flat_map(|crate_impl_defs| {
-                    crate_impl_defs.for_trait_and_self_ty(trait_, fp).map(id_to_chalk)
+                    fps.iter().flat_map(move |fp| {
+                        crate_impl_defs.for_trait_and_self_ty(trait_, *fp).map(id_to_chalk)
+                    })
                 })
-                .collect(),
-            None => impl_maps
-                .iter()
-                .flat_map(|crate_impl_defs| crate_impl_defs.for_trait(trait_).map(id_to_chalk))
-                .collect(),
+                .collect()
         };
 
         let arg: Option<Ty> =