Auto merge of #159836 - adwinwhite:unify-methods, r=lcnr

Unify two `for_each_relevant_impl` methods




We have two similar methods on `tcx` with the same name. It's confusing.

r? lcnr

Author: bors

compiler/rustc_middle/src/ty/context/impl_interner.rs

@@ -539,135 +539,19 @@ impl<'tcx> Interner for TyCtxt<'tcx> {
             .map(|assoc_item| assoc_item.def_id)
     }
 
-    // This implementation is a bit different from `TyCtxt::for_each_relevant_impl`,
-    // since we want to skip over blanket impls for non-rigid aliases, and also we
-    // only want to consider types that *actually* unify with float/int vars.
+    // This signature is a bit different from `TyCtxt::for_each_relevant_impl`.
+    // While rustc only needs self_ty, rust-analyzer's impl needs to use all the args.
     fn for_each_relevant_impl<R: VisitorResult>(
         self,
         trait_ref: ty::TraitRef<'tcx>,
-        mut f: impl FnMut(DefId) -> R,
+        f: impl FnMut(DefId) -> R,
     ) -> R {
-        macro_rules! ret {
-            ($e: expr) => {
-                match $e.branch() {
-                    ControlFlow::Break(b) => return R::from_residual(b),
-                    ControlFlow::Continue(()) => {}
-                }
-            };
-        }
-
-        let trait_def_id = trait_ref.def_id;
-        let self_ty = trait_ref.self_ty();
-        let tcx = self;
-        let trait_impls = tcx.trait_impls_of(trait_def_id);
-        let mut consider_impls_for_simplified_type = |simp| {
-            if let Some(impls_for_type) = trait_impls.non_blanket_impls().get(&simp) {
-                for &impl_def_id in impls_for_type {
-                    ret!(f(impl_def_id))
-                }
-            }
-
-            R::output()
-        };
-
-        match self_ty.kind() {
-            ty::Bool
-            | ty::Char
-            | ty::Int(_)
-            | ty::Uint(_)
-            | ty::Float(_)
-            | ty::Adt(_, _)
-            | ty::Foreign(_)
-            | ty::Str
-            | ty::Array(_, _)
-            | ty::Pat(_, _)
-            | ty::Slice(_)
-            | ty::RawPtr(_, _)
-            | ty::Ref(_, _, _)
-            | ty::FnDef(_, _)
-            | ty::FnPtr(..)
-            | ty::Dynamic(_, _)
-            | ty::Closure(..)
-            | ty::CoroutineClosure(..)
-            | ty::Coroutine(_, _)
-            | ty::Never
-            | ty::Tuple(_)
-            | ty::UnsafeBinder(_) => {
-                if let Some(simp) = ty::fast_reject::simplify_type(
-                    tcx,
-                    self_ty,
-                    ty::fast_reject::TreatParams::AsRigid,
-                ) {
-                    ret!(consider_impls_for_simplified_type(simp));
-                }
-            }
-
-            // HACK: For integer and float variables we have to manually look at all impls
-            // which have some integer or float as a self type.
-            ty::Infer(ty::IntVar(_)) => {
-                use ty::IntTy::*;
-                use ty::UintTy::*;
-                // This causes a compiler error if any new integer kinds are added.
-                let (I8 | I16 | I32 | I64 | I128 | Isize): ty::IntTy;
-                let (U8 | U16 | U32 | U64 | U128 | Usize): ty::UintTy;
-                let possible_integers = [
-                    // signed integers
-                    ty::SimplifiedType::Int(I8),
-                    ty::SimplifiedType::Int(I16),
-                    ty::SimplifiedType::Int(I32),
-                    ty::SimplifiedType::Int(I64),
-                    ty::SimplifiedType::Int(I128),
-                    ty::SimplifiedType::Int(Isize),
-                    // unsigned integers
-                    ty::SimplifiedType::Uint(U8),
-                    ty::SimplifiedType::Uint(U16),
-                    ty::SimplifiedType::Uint(U32),
-                    ty::SimplifiedType::Uint(U64),
-                    ty::SimplifiedType::Uint(U128),
-                    ty::SimplifiedType::Uint(Usize),
-                ];
-                for simp in possible_integers {
-                    ret!(consider_impls_for_simplified_type(simp));
-                }
-            }
-
-            ty::Infer(ty::FloatVar(_)) => {
-                // This causes a compiler error if any new float kinds are added.
-                let (ty::FloatTy::F16 | ty::FloatTy::F32 | ty::FloatTy::F64 | ty::FloatTy::F128);
-                let possible_floats = [
-                    ty::SimplifiedType::Float(ty::FloatTy::F16),
-                    ty::SimplifiedType::Float(ty::FloatTy::F32),
-                    ty::SimplifiedType::Float(ty::FloatTy::F64),
-                    ty::SimplifiedType::Float(ty::FloatTy::F128),
-                ];
-
-                for simp in possible_floats {
-                    ret!(consider_impls_for_simplified_type(simp));
-                }
-            }
-
-            // The only traits applying to aliases and placeholders are blanket impls.
-            //
-            // Impls which apply to an alias after normalization are handled by
-            // `assemble_candidates_after_normalizing_self_ty`.
-            ty::Alias(ty::IsRigid::Yes, _) | ty::Placeholder(..) | ty::Error(_) => (),
-            // FIXME(-Znext-solver=no): Need to support aliases not marked as
-            // rigid for the old solver.
-            ty::Alias(ty::IsRigid::No, _) => (),
-
-            // FIXME: These should ideally not exist as a self type. It would be nice for
-            // the builtin auto trait impls of coroutines to instead directly recurse
-            // into the witness.
-            ty::CoroutineWitness(..) => (),
-
-            // These variants should not exist as a self type.
-            ty::Infer(ty::TyVar(_) | ty::FreshTy(_) | ty::FreshIntTy(_) | ty::FreshFloatTy(_))
-            | ty::Param(_)
-            | ty::Bound(_, _) => bug!("unexpected self type: {self_ty}"),
-        }
-
-        #[allow(rustc::usage_of_type_ir_traits)]
-        self.for_each_blanket_impl(trait_def_id, f)
+        let self_ty = trait_ref.args.type_at(0);
+        debug_assert!(
+            !matches!(self_ty.kind(), ty::Infer(ty::TyVar(_)) | ty::Param(_) | ty::Bound(_, _)),
+            "we should not have them as self ty in the next solver"
+        );
+        TyCtxt::for_each_relevant_impl(self, trait_ref.def_id, self_ty, f)
     }
     fn for_each_blanket_impl<R: VisitorResult>(
         self,

compiler/rustc_middle/src/ty/trait_def.rs

@@ -1,4 +1,5 @@
 use std::iter;
+use std::ops::ControlFlow;
 
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_errors::ErrorGuaranteed;
@@ -13,7 +14,7 @@ use crate::query::LocalCrate;
 use crate::traits::specialization_graph;
 use crate::ty::fast_reject::{self, SimplifiedType, TreatParams};
 use crate::ty::print::{with_crate_prefix, with_no_trimmed_paths};
-use crate::ty::{Ident, Ty, TyCtxt};
+use crate::ty::{self, Ident, Interner, Ty, TyCtxt, VisitorResult};
 
 /// A trait's definition with type information.
 #[derive(StableHash, Encodable, Decodable)]
@@ -182,40 +183,151 @@ impl<'tcx> TyCtxt<'tcx> {
     /// Iterate over every impl that could possibly match the self type `self_ty`.
     ///
     /// `trait_def_id` MUST BE the `DefId` of a trait.
-    pub fn for_each_relevant_impl(
+    pub fn for_each_relevant_impl<R: VisitorResult>(
         self,
         trait_def_id: DefId,
         self_ty: Ty<'tcx>,
-        mut f: impl FnMut(DefId),
-    ) {
-        // FIXME: This depends on the set of all impls for the trait. That is
-        // unfortunate wrt. incremental compilation.
-        //
-        // If we want to be faster, we could have separate queries for
-        // blanket and non-blanket impls, and compare them separately.
-        let impls = self.trait_impls_of(trait_def_id);
-
-        for &impl_def_id in impls.blanket_impls.iter() {
-            f(impl_def_id);
+        mut f: impl FnMut(DefId) -> R,
+    ) -> R {
+        macro_rules! ret {
+            ($e: expr) => {
+                match $e.branch() {
+                    ControlFlow::Break(b) => return R::from_residual(b),
+                    ControlFlow::Continue(()) => {}
+                }
+            };
         }
 
-        // This way, when searching for some impl for `T: Trait`, we do not look at any impls
-        // whose outer level is not a parameter or projection. Especially for things like
-        // `T: Clone` this is incredibly useful as we would otherwise look at all the impls
-        // of `Clone` for `Option<T>`, `Vec<T>`, `ConcreteType` and so on.
-        // Note that we're using `TreatParams::AsRigid` to query `non_blanket_impls` while using
-        // `TreatParams::InstantiateWithInfer` while actually adding them.
-        if let Some(simp) = fast_reject::simplify_type(self, self_ty, TreatParams::AsRigid) {
-            if let Some(impls) = impls.non_blanket_impls.get(&simp) {
-                for &impl_def_id in impls {
-                    f(impl_def_id);
+        let tcx = self;
+        let trait_impls = tcx.trait_impls_of(trait_def_id);
+        let mut consider_impls_for_simplified_type = |simp| {
+            if let Some(impls_for_type) = trait_impls.non_blanket_impls().get(&simp) {
+                for &impl_def_id in impls_for_type {
+                    ret!(f(impl_def_id))
                 }
             }
-        } else {
-            for &impl_def_id in impls.non_blanket_impls.values().flatten() {
-                f(impl_def_id);
+
+            R::output()
+        };
+
+        match self_ty.kind() {
+            ty::Bool
+            | ty::Char
+            | ty::Int(_)
+            | ty::Uint(_)
+            | ty::Float(_)
+            | ty::Adt(_, _)
+            | ty::Foreign(_)
+            | ty::Str
+            | ty::Array(_, _)
+            | ty::Slice(_)
+            | ty::RawPtr(_, _)
+            | ty::Ref(_, _, _)
+            | ty::FnDef(_, _)
+            | ty::FnPtr(..)
+            | ty::Dynamic(_, _)
+            | ty::Closure(..)
+            | ty::CoroutineClosure(..)
+            | ty::Coroutine(_, _)
+            | ty::Never
+            | ty::Tuple(_)
+            | ty::UnsafeBinder(_) => {
+                let simp = ty::fast_reject::simplify_type(
+                    tcx,
+                    self_ty,
+                    ty::fast_reject::TreatParams::AsRigid,
+                )
+                .unwrap();
+                ret!(consider_impls_for_simplified_type(simp));
+            }
+
+            // HACK: For integer and float variables we have to manually look at all impls
+            // which have some integer or float as a self type.
+            ty::Infer(ty::IntVar(_)) => {
+                use ty::IntTy::*;
+                use ty::UintTy::*;
+                // This causes a compiler error if any new integer kinds are added.
+                let (I8 | I16 | I32 | I64 | I128 | Isize): ty::IntTy;
+                let (U8 | U16 | U32 | U64 | U128 | Usize): ty::UintTy;
+                let possible_integers = [
+                    // signed integers
+                    ty::SimplifiedType::Int(I8),
+                    ty::SimplifiedType::Int(I16),
+                    ty::SimplifiedType::Int(I32),
+                    ty::SimplifiedType::Int(I64),
+                    ty::SimplifiedType::Int(I128),
+                    ty::SimplifiedType::Int(Isize),
+                    // unsigned integers
+                    ty::SimplifiedType::Uint(U8),
+                    ty::SimplifiedType::Uint(U16),
+                    ty::SimplifiedType::Uint(U32),
+                    ty::SimplifiedType::Uint(U64),
+                    ty::SimplifiedType::Uint(U128),
+                    ty::SimplifiedType::Uint(Usize),
+                ];
+                for simp in possible_integers {
+                    ret!(consider_impls_for_simplified_type(simp));
+                }
+            }
+
+            ty::Infer(ty::FloatVar(_)) => {
+                // This causes a compiler error if any new float kinds are added.
+                let (ty::FloatTy::F16 | ty::FloatTy::F32 | ty::FloatTy::F64 | ty::FloatTy::F128);
+                let possible_floats = [
+                    ty::SimplifiedType::Float(ty::FloatTy::F16),
+                    ty::SimplifiedType::Float(ty::FloatTy::F32),
+                    ty::SimplifiedType::Float(ty::FloatTy::F64),
+                    ty::SimplifiedType::Float(ty::FloatTy::F128),
+                ];
+
+                for simp in possible_floats {
+                    ret!(consider_impls_for_simplified_type(simp));
+                }
+            }
+
+            // Pattern type might not have a simplified type.
+            ty::Pat(_, _) => {
+                if let Some(simp) = ty::fast_reject::simplify_type(
+                    tcx,
+                    self_ty,
+                    ty::fast_reject::TreatParams::AsRigid,
+                ) {
+                    ret!(consider_impls_for_simplified_type(simp));
+                }
+            }
+
+            // This is only for diagnostics and normally ty vars should be handled by the callers.
+            ty::Infer(ty::TyVar(_)) => {
+                for &impl_def_id in trait_impls.non_blanket_impls().values().flatten() {
+                    ret!(f(impl_def_id));
+                }
+            }
+
+            // The only traits applying to aliases and placeholders are blanket impls.
+            //
+            // Impls which apply to an alias after normalization are handled by
+            // `assemble_candidates_after_normalizing_self_ty`.
+            ty::Alias(ty::IsRigid::Yes, _) | ty::Placeholder(..) | ty::Error(_) => (),
+            // FIXME(-Znext-solver=no): Need to support aliases not marked as
+            // rigid for the old solver.
+            ty::Alias(ty::IsRigid::No, _) => (),
+
+            // FIXME: These should ideally not exist as a self type. It would be nice for
+            // the builtin auto trait impls of coroutines to instead directly recurse
+            // into the witness.
+            ty::CoroutineWitness(..) => (),
+
+            // These are used in diagnostics or in the old solver.
+            ty::Param(_) | ty::Bound(_, _) => (),
+
+            // These variants should not exist as a self type.
+            ty::Infer(ty::FreshTy(_) | ty::FreshIntTy(_) | ty::FreshFloatTy(_)) => {
+                bug!("unexpected self type: {self_ty:?}");
             }
         }
+
+        #[allow(rustc::usage_of_type_ir_traits)]
+        self.for_each_blanket_impl(trait_def_id, f)
     }
 
     /// `trait_def_id` MUST BE the `DefId` of a trait.

tests/ui/methods/inherent-bound-in-probe.rs

@@ -41,7 +41,7 @@ where
 
     fn into_iter(self) -> Self::IntoIter {
         Helper::new(&self.0)
-        //~^ ERROR overflow evaluating the requirement `&_: IntoIterator`
+        //~^ ERROR: overflow evaluating the requirement `&HashMap<_, _, _, _>: IntoIterator`
     }
 }
 

tests/ui/methods/inherent-bound-in-probe.stderr

@@ -12,14 +12,14 @@ LL | struct Helper<'a, T>
 note: required by a bound in `std::iter::IntoIterator::IntoIter`
   --> $SRC_DIR/core/src/iter/traits/collect.rs:LL:COL
 
-error[E0275]: overflow evaluating the requirement `&_: IntoIterator`
+error[E0275]: overflow evaluating the requirement `&HashMap<_, _, _, _>: IntoIterator`
   --> $DIR/inherent-bound-in-probe.rs:43:9
    |
 LL |         Helper::new(&self.0)
    |         ^^^^^^
    |
    = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`inherent_bound_in_probe`)
-note: required for `&BitReaderWrapper<_>` to implement `IntoIterator`
+note: required for `&BitReaderWrapper<HashMap<_, _, _, _>>` to implement `IntoIterator`
   --> $DIR/inherent-bound-in-probe.rs:33:13
    |
 LL | impl<'a, T> IntoIterator for &'a BitReaderWrapper<T>