From 4b76fac3020b27c0cd3cf8b13ff91ee2d26e22ad Mon Sep 17 00:00:00 2001
From: Deadbeef <ent3rm4n@gmail.com>
Date: Sat, 9 Mar 2024 21:27:02 +0800
Subject: [PATCH 1/2] Document some builtin impls in the next solver
---
compiler/rustc_target/src/abi/mod.rs | 1 +
.../src/solve/trait_goals.rs | 39 +++++++++++++++++++
2 files changed, 40 insertions(+)
diff --git a/compiler/rustc_target/src/abi/mod.rs b/compiler/rustc_target/src/abi/mod.rs
index 24e49ff648f..8d1c7c77bb6 100644
--- a/compiler/rustc_target/src/abi/mod.rs
+++ b/compiler/rustc_target/src/abi/mod.rs
@@ -121,6 +121,7 @@ impl<'a> Layout<'a> {
///
/// Currently, that means that the type is pointer-sized, pointer-aligned,
/// and has a initialized (non-union), scalar ABI.
+ // Please also update compiler/rustc_trait_selection/src/solve/trait_goals.rs if the criteria changes
pub fn is_pointer_like(self, data_layout: &TargetDataLayout) -> bool {
self.size() == data_layout.pointer_size
&& self.align().abi == data_layout.pointer_align.abi
diff --git a/compiler/rustc_trait_selection/src/solve/trait_goals.rs b/compiler/rustc_trait_selection/src/solve/trait_goals.rs
index 80198ba39f9..9c2a02a5717 100644
--- a/compiler/rustc_trait_selection/src/solve/trait_goals.rs
+++ b/compiler/rustc_trait_selection/src/solve/trait_goals.rs
@@ -188,6 +188,16 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
})
}
+ /// ```rust,ignore (not valid rust syntax)
+ /// impl Sized for u*, i*, bool, f*, FnPtr, FnDef, *(const/mut) T, char, &mut? T, [T; N], dyn* Trait, !
+ ///
+ /// impl Sized for (T1, T2, .., Tn) where T1: Sized, T2: Sized, .. Tn: Sized
+ ///
+ /// impl Sized for Adt where T: Sized forall T in field types
+ /// ```
+ ///
+ /// note that `[T; N]` is unconditionally sized since `T: Sized` is required for the array type to be
+ /// well-formed.
fn consider_builtin_sized_candidate(
ecx: &mut EvalCtxt<'_, 'tcx>,
goal: Goal<'tcx, Self>,
@@ -202,6 +212,20 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
)
}
+ /// ```rust,ignore (not valid rust syntax)
+ /// impl Copy/Clone for FnDef, FnPtr
+ ///
+ /// impl Copy/Clone for (T1, T2, .., Tn) where T1: Copy/Clone, T2: Copy/Clone, .. Tn: Copy/Clone
+ ///
+ /// impl Copy/Clone for Closure where T: Copy/Clone forall T in upvars
+ ///
+ /// // only when `coroutine_clone` is enabled and the coroutine is movable
+ /// impl Copy/Clone for Coroutine where T: Copy/Clone forall T in (upvars, witnesses)
+ ///
+ /// impl Copy/Clone for CoroutineWitness where T: Copy/Clone forall T in coroutine_hidden_types
+ /// ```
+ ///
+ /// Some built-in types don't have built-in impls because they can be implemented within the standard library.
fn consider_builtin_copy_clone_candidate(
ecx: &mut EvalCtxt<'_, 'tcx>,
goal: Goal<'tcx, Self>,
@@ -216,6 +240,9 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
)
}
+ /// Implements `PointerLike` for types that are pointer-sized, pointer-aligned,
+ /// and have a initialized (non-union), scalar ABI.
+ // Please also update compiler/rustc_target/src/abi/mod.rs if the criteria changes
fn consider_builtin_pointer_like_candidate(
ecx: &mut EvalCtxt<'_, 'tcx>,
goal: Goal<'tcx, Self>,
@@ -245,6 +272,12 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
}
}
+ /// ```rust,ignore (not valid rust syntax)
+ /// impl FnPtr for FnPtr {}
+ /// impl !FnPtr for T where T != FnPtr && T is rigid {}
+ /// ```
+ ///
+ /// Note: see [`Ty::is_known_rigid`] for what it means for the type to be rigid.
fn consider_builtin_fn_ptr_trait_candidate(
ecx: &mut EvalCtxt<'_, 'tcx>,
goal: Goal<'tcx, Self>,
@@ -375,6 +408,12 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
}
}
+ /// ```rust, ignore (not valid rust syntax)
+ /// impl Tuple for () {}
+ /// impl Tuple for (T1,) {}
+ /// impl Tuple for (T1, T2) {}
+ /// impl Tuple for (T1, .., Tn) {}
+ /// ```
fn consider_builtin_tuple_candidate(
ecx: &mut EvalCtxt<'_, 'tcx>,
goal: Goal<'tcx, Self>,
From 69d781abef67abdc8cac65b02bbf75a940734691 Mon Sep 17 00:00:00 2001
From: Deadbeef <ent3rm4n@gmail.com>
Date: Thu, 14 Mar 2024 20:18:04 +0800
Subject: [PATCH 2/2] move impl documentation to their actual locations
---
compiler/rustc_target/src/abi/mod.rs | 1 -
.../src/solve/assembly/structural_traits.rs | 10 ++++++
.../src/solve/trait_goals.rs | 35 ++-----------------
3 files changed, 12 insertions(+), 34 deletions(-)
diff --git a/compiler/rustc_target/src/abi/mod.rs b/compiler/rustc_target/src/abi/mod.rs
index 8d1c7c77bb6..24e49ff648f 100644
--- a/compiler/rustc_target/src/abi/mod.rs
+++ b/compiler/rustc_target/src/abi/mod.rs
@@ -121,7 +121,6 @@ impl<'a> Layout<'a> {
///
/// Currently, that means that the type is pointer-sized, pointer-aligned,
/// and has a initialized (non-union), scalar ABI.
- // Please also update compiler/rustc_trait_selection/src/solve/trait_goals.rs if the criteria changes
pub fn is_pointer_like(self, data_layout: &TargetDataLayout) -> bool {
self.size() == data_layout.pointer_size
&& self.align().abi == data_layout.pointer_align.abi
diff --git a/compiler/rustc_trait_selection/src/solve/assembly/structural_traits.rs b/compiler/rustc_trait_selection/src/solve/assembly/structural_traits.rs
index af533d8db71..2bfb86b592b 100644
--- a/compiler/rustc_trait_selection/src/solve/assembly/structural_traits.rs
+++ b/compiler/rustc_trait_selection/src/solve/assembly/structural_traits.rs
@@ -120,6 +120,8 @@ pub(in crate::solve) fn instantiate_constituent_tys_for_sized_trait<'tcx>(
ty: Ty<'tcx>,
) -> Result<Vec<ty::Binder<'tcx, Ty<'tcx>>>, NoSolution> {
match *ty.kind() {
+ // impl Sized for u*, i*, bool, f*, FnDef, FnPtr, *(const/mut) T, char, &mut? T, [T; N], dyn* Trait, !
+ // impl Sized for Coroutine, CoroutineWitness, Closure, CoroutineClosure
ty::Infer(ty::IntVar(_) | ty::FloatVar(_))
| ty::Uint(_)
| ty::Int(_)
@@ -152,8 +154,10 @@ pub(in crate::solve) fn instantiate_constituent_tys_for_sized_trait<'tcx>(
bug!("unexpected type `{ty}`")
}
+ // impl Sized for (T1, T2, .., Tn) where T1: Sized, T2: Sized, .. Tn: Sized
ty::Tuple(tys) => Ok(tys.iter().map(ty::Binder::dummy).collect()),
+ // impl Sized for Adt where T: Sized forall T in field types
ty::Adt(def, args) => {
let sized_crit = def.sized_constraint(ecx.tcx());
Ok(sized_crit.iter_instantiated(ecx.tcx(), args).map(ty::Binder::dummy).collect())
@@ -167,6 +171,7 @@ pub(in crate::solve) fn instantiate_constituent_tys_for_copy_clone_trait<'tcx>(
ty: Ty<'tcx>,
) -> Result<Vec<ty::Binder<'tcx, Ty<'tcx>>>, NoSolution> {
match *ty.kind() {
+ // impl Copy/Clone for FnDef, FnPtr
ty::FnDef(..) | ty::FnPtr(_) | ty::Error(_) => Ok(vec![]),
// Implementations are provided in core
@@ -196,12 +201,16 @@ pub(in crate::solve) fn instantiate_constituent_tys_for_copy_clone_trait<'tcx>(
bug!("unexpected type `{ty}`")
}
+ // impl Copy/Clone for (T1, T2, .., Tn) where T1: Copy/Clone, T2: Copy/Clone, .. Tn: Copy/Clone
ty::Tuple(tys) => Ok(tys.iter().map(ty::Binder::dummy).collect()),
+ // impl Copy/Clone for Closure where Self::TupledUpvars: Copy/Clone
ty::Closure(_, args) => Ok(vec![ty::Binder::dummy(args.as_closure().tupled_upvars_ty())]),
ty::CoroutineClosure(..) => Err(NoSolution),
+ // only when `coroutine_clone` is enabled and the coroutine is movable
+ // impl Copy/Clone for Coroutine where T: Copy/Clone forall T in (upvars, witnesses)
ty::Coroutine(def_id, args) => match ecx.tcx().coroutine_movability(def_id) {
Movability::Static => Err(NoSolution),
Movability::Movable => {
@@ -217,6 +226,7 @@ pub(in crate::solve) fn instantiate_constituent_tys_for_copy_clone_trait<'tcx>(
}
},
+ // impl Copy/Clone for CoroutineWitness where T: Copy/Clone forall T in coroutine_hidden_types
ty::CoroutineWitness(def_id, args) => Ok(ecx
.tcx()
.coroutine_hidden_types(def_id)
diff --git a/compiler/rustc_trait_selection/src/solve/trait_goals.rs b/compiler/rustc_trait_selection/src/solve/trait_goals.rs
index 9c2a02a5717..ff3fd84af8b 100644
--- a/compiler/rustc_trait_selection/src/solve/trait_goals.rs
+++ b/compiler/rustc_trait_selection/src/solve/trait_goals.rs
@@ -188,16 +188,6 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
})
}
- /// ```rust,ignore (not valid rust syntax)
- /// impl Sized for u*, i*, bool, f*, FnPtr, FnDef, *(const/mut) T, char, &mut? T, [T; N], dyn* Trait, !
- ///
- /// impl Sized for (T1, T2, .., Tn) where T1: Sized, T2: Sized, .. Tn: Sized
- ///
- /// impl Sized for Adt where T: Sized forall T in field types
- /// ```
- ///
- /// note that `[T; N]` is unconditionally sized since `T: Sized` is required for the array type to be
- /// well-formed.
fn consider_builtin_sized_candidate(
ecx: &mut EvalCtxt<'_, 'tcx>,
goal: Goal<'tcx, Self>,
@@ -212,20 +202,6 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
)
}
- /// ```rust,ignore (not valid rust syntax)
- /// impl Copy/Clone for FnDef, FnPtr
- ///
- /// impl Copy/Clone for (T1, T2, .., Tn) where T1: Copy/Clone, T2: Copy/Clone, .. Tn: Copy/Clone
- ///
- /// impl Copy/Clone for Closure where T: Copy/Clone forall T in upvars
- ///
- /// // only when `coroutine_clone` is enabled and the coroutine is movable
- /// impl Copy/Clone for Coroutine where T: Copy/Clone forall T in (upvars, witnesses)
- ///
- /// impl Copy/Clone for CoroutineWitness where T: Copy/Clone forall T in coroutine_hidden_types
- /// ```
- ///
- /// Some built-in types don't have built-in impls because they can be implemented within the standard library.
fn consider_builtin_copy_clone_candidate(
ecx: &mut EvalCtxt<'_, 'tcx>,
goal: Goal<'tcx, Self>,
@@ -240,9 +216,6 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
)
}
- /// Implements `PointerLike` for types that are pointer-sized, pointer-aligned,
- /// and have a initialized (non-union), scalar ABI.
- // Please also update compiler/rustc_target/src/abi/mod.rs if the criteria changes
fn consider_builtin_pointer_like_candidate(
ecx: &mut EvalCtxt<'_, 'tcx>,
goal: Goal<'tcx, Self>,
@@ -272,18 +245,13 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
}
}
- /// ```rust,ignore (not valid rust syntax)
- /// impl FnPtr for FnPtr {}
- /// impl !FnPtr for T where T != FnPtr && T is rigid {}
- /// ```
- ///
- /// Note: see [`Ty::is_known_rigid`] for what it means for the type to be rigid.
fn consider_builtin_fn_ptr_trait_candidate(
ecx: &mut EvalCtxt<'_, 'tcx>,
goal: Goal<'tcx, Self>,
) -> QueryResult<'tcx> {
let self_ty = goal.predicate.self_ty();
match goal.predicate.polarity {
+ // impl FnPtr for FnPtr {}
ty::ImplPolarity::Positive => {
if self_ty.is_fn_ptr() {
ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes)
@@ -291,6 +259,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
Err(NoSolution)
}
}
+ // impl !FnPtr for T where T != FnPtr && T is rigid {}
ty::ImplPolarity::Negative => {
// If a type is rigid and not a fn ptr, then we know for certain
// that it does *not* implement `FnPtr`.