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Auto merge of #112687 - compiler-errors:simplify-impl-source, r=lcnr

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Simplify `ImplSource` candidates a bit

Reduce the number of impl source candidates, which will hopefully make our life easier when trying to adapt things like `SelectionContext::select` and `codegen_select_candidate` for the new solver.

r? `@lcnr` but feel free to reassign
This commit is contained in:
bors 2023-06-17 06:26:55 +00:00
commit f90d57d06e
8 changed files with 186 additions and 384 deletions
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13
compiler/rustc_const_eval/src/transform/check_consts/check.rs
View File

@ -781,8 +781,17 @@ fn visit_terminator(&mut self, terminator: &Terminator<'tcx>, location: Location
);
return;
}
Ok(Some(ImplSource::Closure(data))) => {
if !tcx.is_const_fn_raw(data.closure_def_id) {
// Closure: Fn{Once|Mut}
Ok(Some(ImplSource::Builtin(_)))
if poly_trait_pred.self_ty().skip_binder().is_closure()
&& tcx.fn_trait_kind_from_def_id(trait_id).is_some() =>
{
let ty::Closure(closure_def_id, substs) =
*poly_trait_pred.self_ty().no_bound_vars().unwrap().kind()
else {
unreachable!()
};
if !tcx.is_const_fn_raw(closure_def_id) {
self.check_op(ops::FnCallNonConst {
caller,
callee,

2
compiler/rustc_const_eval/src/transform/check_consts/qualifs.rs
View File

@ -172,7 +172,7 @@ fn in_any_value_of_ty<'tcx>(cx: &ConstCx<'_, 'tcx>, ty: Ty<'tcx>) -> bool {
if !matches!(
impl_src,
ImplSource::ConstDestruct(_) | ImplSource::Param(_, ty::BoundConstness::ConstIfConst)
ImplSource::Builtin(_) | ImplSource::Param(_, ty::BoundConstness::ConstIfConst)
) {
// If our const destruct candidate is not ConstDestruct or implied by the param env,
// then it's bad

156
compiler/rustc_middle/src/traits/mod.rs
View File

@ -646,12 +646,6 @@ pub enum ImplSource<'tcx, N> {
/// ImplSource identifying a particular impl.
UserDefined(ImplSourceUserDefinedData<'tcx, N>),
/// ImplSource for auto trait implementations.
/// This carries the information and nested obligations with regards
/// to an auto implementation for a trait `Trait`. The nested obligations
/// ensure the trait implementation holds for all the constituent types.
AutoImpl(ImplSourceAutoImplData<N>),
/// Successful resolution to an obligation provided by the caller
/// for some type parameter. The `Vec<N>` represents the
/// obligations incurred from normalizing the where-clause (if
@ -659,84 +653,46 @@ pub enum ImplSource<'tcx, N> {
Param(Vec<N>, ty::BoundConstness),
/// Virtual calls through an object.
Object(ImplSourceObjectData<'tcx, N>),
Object(ImplSourceObjectData<N>),
/// Successful resolution for a builtin trait.
Builtin(ImplSourceBuiltinData<N>),
Builtin(Vec<N>),
/// ImplSource for trait upcasting coercion
TraitUpcasting(ImplSourceTraitUpcastingData<'tcx, N>),
/// ImplSource automatically generated for a closure. The `DefId` is the ID
/// of the closure expression. This is an `ImplSource::UserDefined` in spirit, but the
/// impl is generated by the compiler and does not appear in the source.
Closure(ImplSourceClosureData<'tcx, N>),
/// Same as above, but for a function pointer type with the given signature.
FnPointer(ImplSourceFnPointerData<'tcx, N>),
/// ImplSource automatically generated for a generator.
Generator(ImplSourceGeneratorData<'tcx, N>),
/// ImplSource automatically generated for a generator backing an async future.
Future(ImplSourceFutureData<'tcx, N>),
TraitUpcasting(ImplSourceTraitUpcastingData<N>),
/// ImplSource for a trait alias.
TraitAlias(ImplSourceTraitAliasData<'tcx, N>),
/// ImplSource for a `const Drop` implementation.
ConstDestruct(ImplSourceConstDestructData<N>),
}
impl<'tcx, N> ImplSource<'tcx, N> {
pub fn nested_obligations(self) -> Vec<N> {
match self {
ImplSource::UserDefined(i) => i.nested,
ImplSource::Param(n, _) => n,
ImplSource::Builtin(i) => i.nested,
ImplSource::AutoImpl(d) => d.nested,
ImplSource::Closure(c) => c.nested,
ImplSource::Generator(c) => c.nested,
ImplSource::Future(c) => c.nested,
ImplSource::Param(n, _) | ImplSource::Builtin(n) => n,
ImplSource::Object(d) => d.nested,
ImplSource::FnPointer(d) => d.nested,
ImplSource::TraitAlias(d) => d.nested,
ImplSource::TraitUpcasting(d) => d.nested,
ImplSource::ConstDestruct(i) => i.nested,
}
}
pub fn borrow_nested_obligations(&self) -> &[N] {
match self {
ImplSource::UserDefined(i) => &i.nested,
ImplSource::Param(n, _) => n,
ImplSource::Builtin(i) => &i.nested,
ImplSource::AutoImpl(d) => &d.nested,
ImplSource::Closure(c) => &c.nested,
ImplSource::Generator(c) => &c.nested,
ImplSource::Future(c) => &c.nested,
ImplSource::Param(n, _) | ImplSource::Builtin(n) => &n,
ImplSource::Object(d) => &d.nested,
ImplSource::FnPointer(d) => &d.nested,
ImplSource::TraitAlias(d) => &d.nested,
ImplSource::TraitUpcasting(d) => &d.nested,
ImplSource::ConstDestruct(i) => &i.nested,
}
}
pub fn borrow_nested_obligations_mut(&mut self) -> &mut [N] {
match self {
ImplSource::UserDefined(i) => &mut i.nested,
ImplSource::Param(n, _) => n,
ImplSource::Builtin(i) => &mut i.nested,
ImplSource::AutoImpl(d) => &mut d.nested,
ImplSource::Closure(c) => &mut c.nested,
ImplSource::Generator(c) => &mut c.nested,
ImplSource::Future(c) => &mut c.nested,
ImplSource::Param(n, _) | ImplSource::Builtin(n) => n,
ImplSource::Object(d) => &mut d.nested,
ImplSource::FnPointer(d) => &mut d.nested,
ImplSource::TraitAlias(d) => &mut d.nested,
ImplSource::TraitUpcasting(d) => &mut d.nested,
ImplSource::ConstDestruct(i) => &mut i.nested,
}
}
@ -751,37 +707,12 @@ pub fn map<M, F>(self, f: F) -> ImplSource<'tcx, M>
nested: i.nested.into_iter().map(f).collect(),
}),
ImplSource::Param(n, ct) => ImplSource::Param(n.into_iter().map(f).collect(), ct),
ImplSource::Builtin(i) => ImplSource::Builtin(ImplSourceBuiltinData {
nested: i.nested.into_iter().map(f).collect(),
}),
ImplSource::Builtin(n) => ImplSource::Builtin(n.into_iter().map(f).collect()),
ImplSource::Object(o) => ImplSource::Object(ImplSourceObjectData {
upcast_trait_ref: o.upcast_trait_ref,
upcast_trait_def_id: o.upcast_trait_def_id,
vtable_base: o.vtable_base,
nested: o.nested.into_iter().map(f).collect(),
}),
ImplSource::AutoImpl(d) => ImplSource::AutoImpl(ImplSourceAutoImplData {
trait_def_id: d.trait_def_id,
nested: d.nested.into_iter().map(f).collect(),
}),
ImplSource::Closure(c) => ImplSource::Closure(ImplSourceClosureData {
closure_def_id: c.closure_def_id,
substs: c.substs,
nested: c.nested.into_iter().map(f).collect(),
}),
ImplSource::Generator(c) => ImplSource::Generator(ImplSourceGeneratorData {
generator_def_id: c.generator_def_id,
substs: c.substs,
nested: c.nested.into_iter().map(f).collect(),
}),
ImplSource::Future(c) => ImplSource::Future(ImplSourceFutureData {
generator_def_id: c.generator_def_id,
substs: c.substs,
nested: c.nested.into_iter().map(f).collect(),
}),
ImplSource::FnPointer(p) => ImplSource::FnPointer(ImplSourceFnPointerData {
fn_ty: p.fn_ty,
nested: p.nested.into_iter().map(f).collect(),
}),
ImplSource::TraitAlias(d) => ImplSource::TraitAlias(ImplSourceTraitAliasData {
alias_def_id: d.alias_def_id,
substs: d.substs,
@ -789,16 +720,10 @@ pub fn map<M, F>(self, f: F) -> ImplSource<'tcx, M>
}),
ImplSource::TraitUpcasting(d) => {
ImplSource::TraitUpcasting(ImplSourceTraitUpcastingData {
upcast_trait_ref: d.upcast_trait_ref,
vtable_vptr_slot: d.vtable_vptr_slot,
nested: d.nested.into_iter().map(f).collect(),
})
}
ImplSource::ConstDestruct(i) => {
ImplSource::ConstDestruct(ImplSourceConstDestructData {
nested: i.nested.into_iter().map(f).collect(),
})
}
}
}
}
@ -823,47 +748,7 @@ pub struct ImplSourceUserDefinedData<'tcx, N> {
#[derive(Clone, PartialEq, Eq, TyEncodable, TyDecodable, HashStable, Lift)]
#[derive(TypeFoldable, TypeVisitable)]
pub struct ImplSourceGeneratorData<'tcx, N> {
pub generator_def_id: DefId,
pub substs: SubstsRef<'tcx>,
/// Nested obligations. This can be non-empty if the generator
/// signature contains associated types.
pub nested: Vec<N>,
}
#[derive(Clone, PartialEq, Eq, TyEncodable, TyDecodable, HashStable, Lift)]
#[derive(TypeFoldable, TypeVisitable)]
pub struct ImplSourceFutureData<'tcx, N> {
pub generator_def_id: DefId,
pub substs: SubstsRef<'tcx>,
/// Nested obligations. This can be non-empty if the generator
/// signature contains associated types.
pub nested: Vec<N>,
}
#[derive(Clone, PartialEq, Eq, TyEncodable, TyDecodable, HashStable, Lift)]
#[derive(TypeFoldable, TypeVisitable)]
pub struct ImplSourceClosureData<'tcx, N> {
pub closure_def_id: DefId,
pub substs: SubstsRef<'tcx>,
/// Nested obligations. This can be non-empty if the closure
/// signature contains associated types.
pub nested: Vec<N>,
}
#[derive(Clone, PartialEq, Eq, TyEncodable, TyDecodable, HashStable, Lift)]
#[derive(TypeFoldable, TypeVisitable)]
pub struct ImplSourceAutoImplData<N> {
pub trait_def_id: DefId,
pub nested: Vec<N>,
}
#[derive(Clone, PartialEq, Eq, TyEncodable, TyDecodable, HashStable, Lift)]
#[derive(TypeFoldable, TypeVisitable)]
pub struct ImplSourceTraitUpcastingData<'tcx, N> {
/// `Foo` upcast to the obligation trait. This will be some supertrait of `Foo`.
pub upcast_trait_ref: ty::PolyTraitRef<'tcx>,
pub struct ImplSourceTraitUpcastingData<N> {
/// The vtable is formed by concatenating together the method lists of
/// the base object trait and all supertraits, pointers to supertrait vtable will
/// be provided when necessary; this is the position of `upcast_trait_ref`'s vtable
@ -873,17 +758,11 @@ pub struct ImplSourceTraitUpcastingData<'tcx, N> {
pub nested: Vec<N>,
}
#[derive(Clone, PartialEq, Eq, TyEncodable, TyDecodable, HashStable, Lift)]
#[derive(TypeFoldable, TypeVisitable)]
pub struct ImplSourceBuiltinData<N> {
pub nested: Vec<N>,
}
#[derive(PartialEq, Eq, Clone, TyEncodable, TyDecodable, HashStable, Lift)]
#[derive(TypeFoldable, TypeVisitable)]
pub struct ImplSourceObjectData<'tcx, N> {
pub struct ImplSourceObjectData<N> {
/// `Foo` upcast to the obligation trait. This will be some supertrait of `Foo`.
pub upcast_trait_ref: ty::PolyTraitRef<'tcx>,
pub upcast_trait_def_id: DefId,
/// The vtable is formed by concatenating together the method lists of
/// the base object trait and all supertraits, pointers to supertrait vtable will
@ -894,19 +773,6 @@ pub struct ImplSourceObjectData<'tcx, N> {
pub nested: Vec<N>,
}
#[derive(Clone, PartialEq, Eq, TyEncodable, TyDecodable, HashStable, Lift)]
#[derive(TypeFoldable, TypeVisitable)]
pub struct ImplSourceFnPointerData<'tcx, N> {
pub fn_ty: Ty<'tcx>,
pub nested: Vec<N>,
}
#[derive(Clone, PartialEq, Eq, TyEncodable, TyDecodable, HashStable, Lift)]
#[derive(TypeFoldable, TypeVisitable)]
pub struct ImplSourceConstDestructData<N> {
pub nested: Vec<N>,
}
#[derive(Clone, PartialEq, Eq, TyEncodable, TyDecodable, HashStable, Lift)]
#[derive(TypeFoldable, TypeVisitable)]
pub struct ImplSourceTraitAliasData<'tcx, N> {

82
compiler/rustc_middle/src/traits/structural_impls.rs
View File

@ -9,15 +9,7 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match *self {
super::ImplSource::UserDefined(ref v) => write!(f, "{:?}", v),
super::ImplSource::AutoImpl(ref t) => write!(f, "{:?}", t),
super::ImplSource::Closure(ref d) => write!(f, "{:?}", d),
super::ImplSource::Generator(ref d) => write!(f, "{:?}", d),
super::ImplSource::Future(ref d) => write!(f, "{:?}", d),
super::ImplSource::FnPointer(ref d) => write!(f, "({:?})", d),
super::ImplSource::Builtin(ref d) => write!(f, "{:?}", d),
super::ImplSource::Object(ref d) => write!(f, "{:?}", d),
@ -25,13 +17,9 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "ImplSourceParamData({:?}, {:?})", n, ct)
}
super::ImplSource::Builtin(ref d) => write!(f, "{:?}", d),
super::ImplSource::TraitAlias(ref d) => write!(f, "{:?}", d),
super::ImplSource::TraitUpcasting(ref d) => write!(f, "{:?}", d),
super::ImplSource::ConstDestruct(ref d) => write!(f, "{:?}", d),
}
}
}
@ -46,78 +34,26 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
}
}
impl<'tcx, N: fmt::Debug> fmt::Debug for traits::ImplSourceGeneratorData<'tcx, N> {
impl<N: fmt::Debug> fmt::Debug for traits::ImplSourceTraitUpcastingData<N> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(
f,
"ImplSourceGeneratorData(generator_def_id={:?}, substs={:?}, nested={:?})",
self.generator_def_id, self.substs, self.nested
"ImplSourceTraitUpcastingData(vtable_vptr_slot={:?}, nested={:?})",
self.vtable_vptr_slot, self.nested
)
}
}
impl<'tcx, N: fmt::Debug> fmt::Debug for traits::ImplSourceFutureData<'tcx, N> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(
f,
"ImplSourceFutureData(generator_def_id={:?}, substs={:?}, nested={:?})",
self.generator_def_id, self.substs, self.nested
)
}
}
impl<'tcx, N: fmt::Debug> fmt::Debug for traits::ImplSourceClosureData<'tcx, N> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(
f,
"ImplSourceClosureData(closure_def_id={:?}, substs={:?}, nested={:?})",
self.closure_def_id, self.substs, self.nested
)
}
}
impl<N: fmt::Debug> fmt::Debug for traits::ImplSourceBuiltinData<N> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "ImplSourceBuiltinData(nested={:?})", self.nested)
}
}
impl<'tcx, N: fmt::Debug> fmt::Debug for traits::ImplSourceTraitUpcastingData<'tcx, N> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(
f,
"ImplSourceTraitUpcastingData(upcast={:?}, vtable_vptr_slot={:?}, nested={:?})",
self.upcast_trait_ref, self.vtable_vptr_slot, self.nested
)
}
}
impl<N: fmt::Debug> fmt::Debug for traits::ImplSourceAutoImplData<N> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(
f,
"ImplSourceAutoImplData(trait_def_id={:?}, nested={:?})",
self.trait_def_id, self.nested
)
}
}
impl<'tcx, N: fmt::Debug> fmt::Debug for traits::ImplSourceObjectData<'tcx, N> {
impl<N: fmt::Debug> fmt::Debug for traits::ImplSourceObjectData<N> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(
f,
"ImplSourceObjectData(upcast={:?}, vtable_base={}, nested={:?})",
self.upcast_trait_ref, self.vtable_base, self.nested
self.upcast_trait_def_id, self.vtable_base, self.nested
)
}
}
impl<'tcx, N: fmt::Debug> fmt::Debug for traits::ImplSourceFnPointerData<'tcx, N> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "ImplSourceFnPointerData(fn_ty={:?}, nested={:?})", self.fn_ty, self.nested)
}
}
impl<'tcx, N: fmt::Debug> fmt::Debug for traits::ImplSourceTraitAliasData<'tcx, N> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(
@ -127,9 +63,3 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
)
}
}
impl<N: fmt::Debug> fmt::Debug for traits::ImplSourceConstDestructData<N> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "ImplSourceConstDestructData(nested={:?})", self.nested)
}
}

91
compiler/rustc_trait_selection/src/traits/project.rs
View File

@ -3,6 +3,7 @@
use super::specialization_graph;
use super::translate_substs;
use super::util;
use super::ImplSourceUserDefinedData;
use super::MismatchedProjectionTypes;
use super::Obligation;
use super::ObligationCause;
@ -10,10 +11,6 @@
use super::Selection;
use super::SelectionContext;
use super::SelectionError;
use super::{
ImplSourceClosureData, ImplSourceFnPointerData, ImplSourceFutureData, ImplSourceGeneratorData,
ImplSourceUserDefinedData,
};
use super::{Normalized, NormalizedTy, ProjectionCacheEntry, ProjectionCacheKey};
use crate::errors::InherentProjectionNormalizationOverflow;
@ -30,7 +27,6 @@
use rustc_infer::infer::at::At;
use rustc_infer::infer::resolve::OpportunisticRegionResolver;
use rustc_infer::infer::DefineOpaqueTypes;
use rustc_infer::traits::ImplSourceBuiltinData;
use rustc_infer::traits::ObligationCauseCode;
use rustc_middle::traits::select::OverflowError;
use rustc_middle::ty::fold::{TypeFoldable, TypeFolder, TypeSuperFoldable};
@ -1721,11 +1717,7 @@ fn assemble_candidates_from_impls<'cx, 'tcx>(
};
let eligible = match &impl_source {
super::ImplSource::Closure(_)
| super::ImplSource::Generator(_)
| super::ImplSource::Future(_)
| super::ImplSource::FnPointer(_)
| super::ImplSource::TraitAlias(_) => true,
super::ImplSource::TraitAlias(_) => true,
super::ImplSource::UserDefined(impl_data) => {
// We have to be careful when projecting out of an
// impl because of specialization. If we are not in
@ -1783,7 +1775,11 @@ fn assemble_candidates_from_impls<'cx, 'tcx>(
let self_ty = selcx.infcx.shallow_resolve(obligation.predicate.self_ty());
let lang_items = selcx.tcx().lang_items();
if lang_items.discriminant_kind_trait() == Some(poly_trait_ref.def_id()) {
if [lang_items.gen_trait(), lang_items.future_trait()].contains(&Some(poly_trait_ref.def_id()))
|| selcx.tcx().fn_trait_kind_from_def_id(poly_trait_ref.def_id()).is_some()
{
true
} else if lang_items.discriminant_kind_trait() == Some(poly_trait_ref.def_id()) {
match self_ty.kind() {
ty::Bool
| ty::Char
@ -1930,9 +1926,7 @@ fn assemble_candidates_from_impls<'cx, 'tcx>(
// why we special case object types.
false
}
super::ImplSource::AutoImpl(..)
| super::ImplSource::TraitUpcasting(_)
| super::ImplSource::ConstDestruct(_) => {
| super::ImplSource::TraitUpcasting(_) => {
// These traits have no associated types.
selcx.tcx().sess.delay_span_bug(
obligation.cause.span,
@ -1996,17 +1990,27 @@ fn confirm_select_candidate<'cx, 'tcx>(
) -> Progress<'tcx> {
match impl_source {
super::ImplSource::UserDefined(data) => confirm_impl_candidate(selcx, obligation, data),
super::ImplSource::Generator(data) => confirm_generator_candidate(selcx, obligation, data),
super::ImplSource::Future(data) => confirm_future_candidate(selcx, obligation, data),
super::ImplSource::Closure(data) => confirm_closure_candidate(selcx, obligation, data),
super::ImplSource::FnPointer(data) => confirm_fn_pointer_candidate(selcx, obligation, data),
super::ImplSource::Builtin(data) => confirm_builtin_candidate(selcx, obligation, data),
super::ImplSource::Builtin(data) => {
let trait_def_id = obligation.predicate.trait_def_id(selcx.tcx());
let lang_items = selcx.tcx().lang_items();
if lang_items.gen_trait() == Some(trait_def_id) {
confirm_generator_candidate(selcx, obligation, data)
} else if lang_items.future_trait() == Some(trait_def_id) {
confirm_future_candidate(selcx, obligation, data)
} else if selcx.tcx().fn_trait_kind_from_def_id(trait_def_id).is_some() {
if obligation.predicate.self_ty().is_closure() {
confirm_closure_candidate(selcx, obligation, data)
} else {
confirm_fn_pointer_candidate(selcx, obligation, data)
}
} else {
confirm_builtin_candidate(selcx, obligation, data)
}
}
super::ImplSource::Object(_)
| super::ImplSource::AutoImpl(..)
| super::ImplSource::Param(..)
| super::ImplSource::TraitUpcasting(_)
| super::ImplSource::TraitAlias(..)
| super::ImplSource::ConstDestruct(_) => {
| super::ImplSource::TraitAlias(..) => {
// we don't create Select candidates with this kind of resolution
span_bug!(
obligation.cause.span,
@ -2020,9 +2024,14 @@ fn confirm_select_candidate<'cx, 'tcx>(
fn confirm_generator_candidate<'cx, 'tcx>(
selcx: &mut SelectionContext<'cx, 'tcx>,
obligation: &ProjectionTyObligation<'tcx>,
impl_source: ImplSourceGeneratorData<'tcx, PredicateObligation<'tcx>>,
nested: Vec<PredicateObligation<'tcx>>,
) -> Progress<'tcx> {
let gen_sig = impl_source.substs.as_generator().poly_sig();
let ty::Generator(_, substs, _) =
selcx.infcx.shallow_resolve(obligation.predicate.self_ty()).kind()
else {
unreachable!()
};
let gen_sig = substs.as_generator().poly_sig();
let Normalized { value: gen_sig, obligations } = normalize_with_depth(
selcx,
obligation.param_env,
@ -2060,16 +2069,21 @@ fn confirm_generator_candidate<'cx, 'tcx>(
});
confirm_param_env_candidate(selcx, obligation, predicate, false)
.with_addl_obligations(impl_source.nested)
.with_addl_obligations(nested)
.with_addl_obligations(obligations)
}
fn confirm_future_candidate<'cx, 'tcx>(
selcx: &mut SelectionContext<'cx, 'tcx>,
obligation: &ProjectionTyObligation<'tcx>,
impl_source: ImplSourceFutureData<'tcx, PredicateObligation<'tcx>>,
nested: Vec<PredicateObligation<'tcx>>,
) -> Progress<'tcx> {
let gen_sig = impl_source.substs.as_generator().poly_sig();
let ty::Generator(_, substs, _) =
selcx.infcx.shallow_resolve(obligation.predicate.self_ty()).kind()
else {
unreachable!()
};
let gen_sig = substs.as_generator().poly_sig();
let Normalized { value: gen_sig, obligations } = normalize_with_depth(
selcx,
obligation.param_env,
@ -2099,14 +2113,14 @@ fn confirm_future_candidate<'cx, 'tcx>(
});
confirm_param_env_candidate(selcx, obligation, predicate, false)
.with_addl_obligations(impl_source.nested)
.with_addl_obligations(nested)
.with_addl_obligations(obligations)
}
fn confirm_builtin_candidate<'cx, 'tcx>(
selcx: &mut SelectionContext<'cx, 'tcx>,
obligation: &ProjectionTyObligation<'tcx>,
data: ImplSourceBuiltinData<PredicateObligation<'tcx>>,
data: Vec<PredicateObligation<'tcx>>,
) -> Progress<'tcx> {
let tcx = selcx.tcx();
let self_ty = obligation.predicate.self_ty();
@ -2154,15 +2168,15 @@ fn confirm_builtin_candidate<'cx, 'tcx>(
confirm_param_env_candidate(selcx, obligation, ty::Binder::dummy(predicate), false)
.with_addl_obligations(obligations)
.with_addl_obligations(data.nested)
.with_addl_obligations(data)
}
fn confirm_fn_pointer_candidate<'cx, 'tcx>(
selcx: &mut SelectionContext<'cx, 'tcx>,
obligation: &ProjectionTyObligation<'tcx>,
fn_pointer_impl_source: ImplSourceFnPointerData<'tcx, PredicateObligation<'tcx>>,
nested: Vec<PredicateObligation<'tcx>>,
) -> Progress<'tcx> {
let fn_type = selcx.infcx.shallow_resolve(fn_pointer_impl_source.fn_ty);
let fn_type = selcx.infcx.shallow_resolve(obligation.predicate.self_ty());
let sig = fn_type.fn_sig(selcx.tcx());
let Normalized { value: sig, obligations } = normalize_with_depth(
selcx,
@ -2173,16 +2187,21 @@ fn confirm_fn_pointer_candidate<'cx, 'tcx>(
);
confirm_callable_candidate(selcx, obligation, sig, util::TupleArgumentsFlag::Yes)
.with_addl_obligations(fn_pointer_impl_source.nested)
.with_addl_obligations(nested)
.with_addl_obligations(obligations)
}
fn confirm_closure_candidate<'cx, 'tcx>(
selcx: &mut SelectionContext<'cx, 'tcx>,
obligation: &ProjectionTyObligation<'tcx>,
impl_source: ImplSourceClosureData<'tcx, PredicateObligation<'tcx>>,
nested: Vec<PredicateObligation<'tcx>>,
) -> Progress<'tcx> {
let closure_sig = impl_source.substs.as_closure().sig();
let ty::Closure(_, substs) =
selcx.infcx.shallow_resolve(obligation.predicate.self_ty()).kind()
else {
unreachable!()
};
let closure_sig = substs.as_closure().sig();
let Normalized { value: closure_sig, obligations } = normalize_with_depth(
selcx,
obligation.param_env,
@ -2194,7 +2213,7 @@ fn confirm_closure_candidate<'cx, 'tcx>(
debug!(?obligation, ?closure_sig, ?obligations, "confirm_closure_candidate");
confirm_callable_candidate(selcx, obligation, closure_sig, util::TupleArgumentsFlag::No)
.with_addl_obligations(impl_source.nested)
.with_addl_obligations(nested)
.with_addl_obligations(obligations)
}

77
compiler/rustc_trait_selection/src/traits/select/confirmation.rs
View File

@ -27,11 +27,9 @@
};
use crate::traits::{
BuiltinDerivedObligation, ImplDerivedObligation, ImplDerivedObligationCause, ImplSource,
ImplSourceAutoImplData, ImplSourceBuiltinData, ImplSourceClosureData,
ImplSourceConstDestructData, ImplSourceFnPointerData, ImplSourceFutureData,
ImplSourceGeneratorData, ImplSourceObjectData, ImplSourceTraitAliasData,
ImplSourceTraitUpcastingData, ImplSourceUserDefinedData, Normalized, Obligation,
ObligationCause, OutputTypeParameterMismatch, PredicateObligation, Selection, SelectionError,
ImplSourceObjectData, ImplSourceTraitAliasData, ImplSourceTraitUpcastingData,
ImplSourceUserDefinedData, Normalized, Obligation, ObligationCause,
OutputTypeParameterMismatch, PredicateObligation, Selection, SelectionError,
TraitNotObjectSafe, TraitObligation, Unimplemented,
};
@ -72,7 +70,7 @@ pub(super) fn confirm_candidate(
AutoImplCandidate => {
let data = self.confirm_auto_impl_candidate(obligation);
ImplSource::AutoImpl(data)
ImplSource::Builtin(data)
}
ProjectionCandidate(idx, constness) => {
@ -87,22 +85,22 @@ pub(super) fn confirm_candidate(
ClosureCandidate { .. } => {
let vtable_closure = self.confirm_closure_candidate(obligation)?;
ImplSource::Closure(vtable_closure)
ImplSource::Builtin(vtable_closure)
}
GeneratorCandidate => {
let vtable_generator = self.confirm_generator_candidate(obligation)?;
ImplSource::Generator(vtable_generator)
ImplSource::Builtin(vtable_generator)
}
FutureCandidate => {
let vtable_future = self.confirm_future_candidate(obligation)?;
ImplSource::Future(vtable_future)
ImplSource::Builtin(vtable_future)
}
FnPointerCandidate { is_const } => {
let data = self.confirm_fn_pointer_candidate(obligation, is_const)?;
ImplSource::FnPointer(data)
ImplSource::Builtin(data)
}
TraitAliasCandidate => {
@ -114,7 +112,7 @@ pub(super) fn confirm_candidate(
// This indicates something like `Trait + Send: Send`. In this case, we know that
// this holds because that's what the object type is telling us, and there's really
// no additional obligations to prove and no types in particular to unify, etc.
ImplSource::Param(Vec::new(), ty::BoundConstness::NotConst)
ImplSource::Builtin(Vec::new())
}
BuiltinUnsizeCandidate => {
@ -129,7 +127,7 @@ pub(super) fn confirm_candidate(
ConstDestructCandidate(def_id) => {
let data = self.confirm_const_destruct_candidate(obligation, def_id)?;
ImplSource::ConstDestruct(data)
ImplSource::Builtin(data)
}
};
@ -244,7 +242,7 @@ fn confirm_builtin_candidate(
&mut self,
obligation: &TraitObligation<'tcx>,
has_nested: bool,
) -> ImplSourceBuiltinData<PredicateObligation<'tcx>> {
) -> Vec<PredicateObligation<'tcx>> {
debug!(?obligation, ?has_nested, "confirm_builtin_candidate");
let lang_items = self.tcx().lang_items();
@ -277,14 +275,14 @@ fn confirm_builtin_candidate(
debug!(?obligations);
ImplSourceBuiltinData { nested: obligations }
obligations
}
#[instrument(level = "debug", skip(self))]
fn confirm_transmutability_candidate(
&mut self,
obligation: &TraitObligation<'tcx>,
) -> Result<ImplSourceBuiltinData<PredicateObligation<'tcx>>, SelectionError<'tcx>> {
) -> Result<Vec<PredicateObligation<'tcx>>, SelectionError<'tcx>> {
use rustc_transmute::{Answer, Condition};
#[instrument(level = "debug", skip(tcx, obligation, predicate))]
fn flatten_answer_tree<'tcx>(
@ -369,7 +367,7 @@ fn flatten_answer_tree<'tcx>(
};
debug!(?fully_flattened);
Ok(ImplSourceBuiltinData { nested: fully_flattened })
Ok(fully_flattened)
}
/// This handles the case where an `auto trait Foo` impl is being used.
@ -380,7 +378,7 @@ fn flatten_answer_tree<'tcx>(
fn confirm_auto_impl_candidate(
&mut self,
obligation: &TraitObligation<'tcx>,
) -> ImplSourceAutoImplData<PredicateObligation<'tcx>> {
) -> Vec<PredicateObligation<'tcx>> {
debug!(?obligation, "confirm_auto_impl_candidate");
let self_ty = self.infcx.shallow_resolve(obligation.predicate.self_ty());
@ -394,7 +392,7 @@ fn vtable_auto_impl(
obligation: &TraitObligation<'tcx>,
trait_def_id: DefId,
nested: ty::Binder<'tcx, Vec<Ty<'tcx>>>,
) -> ImplSourceAutoImplData<PredicateObligation<'tcx>> {
) -> Vec<PredicateObligation<'tcx>> {
debug!(?nested, "vtable_auto_impl");
ensure_sufficient_stack(|| {
let cause = obligation.derived_cause(BuiltinDerivedObligation);
@ -424,7 +422,7 @@ fn vtable_auto_impl(
debug!(?obligations, "vtable_auto_impl");
ImplSourceAutoImplData { trait_def_id, nested: obligations }
obligations
})
}
@ -487,7 +485,7 @@ fn confirm_object_candidate(
&mut self,
obligation: &TraitObligation<'tcx>,
index: usize,
) -> Result<ImplSourceObjectData<'tcx, PredicateObligation<'tcx>>, SelectionError<'tcx>> {
) -> Result<ImplSourceObjectData<PredicateObligation<'tcx>>, SelectionError<'tcx>> {
let tcx = self.tcx();
debug!(?obligation, ?index, "confirm_object_candidate");
@ -654,15 +652,18 @@ fn confirm_object_candidate(
(unnormalized_upcast_trait_ref, ty::Binder::dummy(object_trait_ref)),
);
Ok(ImplSourceObjectData { upcast_trait_ref, vtable_base, nested })
Ok(ImplSourceObjectData {
upcast_trait_def_id: upcast_trait_ref.def_id(),
vtable_base,
nested,
})
}
fn confirm_fn_pointer_candidate(
&mut self,
obligation: &TraitObligation<'tcx>,
is_const: bool,
) -> Result<ImplSourceFnPointerData<'tcx, PredicateObligation<'tcx>>, SelectionError<'tcx>>
{
) -> Result<Vec<PredicateObligation<'tcx>>, SelectionError<'tcx>> {
debug!(?obligation, "confirm_fn_pointer_candidate");
let tcx = self.tcx();
@ -714,7 +715,7 @@ fn confirm_fn_pointer_candidate(
let tr = ty::TraitRef::from_lang_item(self.tcx(), LangItem::Sized, cause.span, [output_ty]);
nested.push(Obligation::new(self.infcx.tcx, cause, obligation.param_env, tr));
Ok(ImplSourceFnPointerData { fn_ty: self_ty, nested })
Ok(nested)
}
fn confirm_trait_alias_candidate(
@ -746,8 +747,7 @@ fn confirm_trait_alias_candidate(
fn confirm_generator_candidate(
&mut self,
obligation: &TraitObligation<'tcx>,
) -> Result<ImplSourceGeneratorData<'tcx, PredicateObligation<'tcx>>, SelectionError<'tcx>>
{
) -> Result<Vec<PredicateObligation<'tcx>>, SelectionError<'tcx>> {
// Okay to skip binder because the substs on generator types never
// touch bound regions, they just capture the in-scope
// type/region parameters.
@ -780,13 +780,13 @@ fn confirm_generator_candidate(
let nested = self.confirm_poly_trait_refs(obligation, trait_ref)?;
debug!(?trait_ref, ?nested, "generator candidate obligations");
Ok(ImplSourceGeneratorData { generator_def_id, substs, nested })
Ok(nested)
}
fn confirm_future_candidate(
&mut self,
obligation: &TraitObligation<'tcx>,
) -> Result<ImplSourceFutureData<'tcx, PredicateObligation<'tcx>>, SelectionError<'tcx>> {
) -> Result<Vec<PredicateObligation<'tcx>>, SelectionError<'tcx>> {
// Okay to skip binder because the substs on generator types never
// touch bound regions, they just capture the in-scope
// type/region parameters.
@ -810,14 +810,14 @@ fn confirm_future_candidate(
let nested = self.confirm_poly_trait_refs(obligation, trait_ref)?;
debug!(?trait_ref, ?nested, "future candidate obligations");
Ok(ImplSourceFutureData { generator_def_id, substs, nested })
Ok(nested)
}
#[instrument(skip(self), level = "debug")]
fn confirm_closure_candidate(
&mut self,
obligation: &TraitObligation<'tcx>,
) -> Result<ImplSourceClosureData<'tcx, PredicateObligation<'tcx>>, SelectionError<'tcx>> {
) -> Result<Vec<PredicateObligation<'tcx>>, SelectionError<'tcx>> {
let kind = self
.tcx()
.fn_trait_kind_from_def_id(obligation.predicate.def_id())
@ -844,7 +844,7 @@ fn confirm_closure_candidate(
));
}
Ok(ImplSourceClosureData { closure_def_id, substs, nested })
Ok(nested)
}
/// In the case of closure types and fn pointers,
@ -912,8 +912,7 @@ fn confirm_trait_upcasting_unsize_candidate(
&mut self,
obligation: &TraitObligation<'tcx>,
idx: usize,
) -> Result<ImplSourceTraitUpcastingData<'tcx, PredicateObligation<'tcx>>, SelectionError<'tcx>>
{
) -> Result<ImplSourceTraitUpcastingData<PredicateObligation<'tcx>>, SelectionError<'tcx>> {
let tcx = self.tcx();
// `assemble_candidates_for_unsizing` should ensure there are no late-bound
@ -1010,13 +1009,13 @@ fn confirm_trait_upcasting_unsize_candidate(
let vtable_vptr_slot =
prepare_vtable_segments(tcx, source_trait_ref, vtable_segment_callback).unwrap();
Ok(ImplSourceTraitUpcastingData { upcast_trait_ref, vtable_vptr_slot, nested })
Ok(ImplSourceTraitUpcastingData { vtable_vptr_slot, nested })
}
fn confirm_builtin_unsize_candidate(
&mut self,
obligation: &TraitObligation<'tcx>,
) -> Result<ImplSourceBuiltinData<PredicateObligation<'tcx>>, SelectionError<'tcx>> {
) -> Result<Vec<PredicateObligation<'tcx>>, SelectionError<'tcx>> {
let tcx = self.tcx();
// `assemble_candidates_for_unsizing` should ensure there are no late-bound
@ -1217,17 +1216,17 @@ fn confirm_builtin_unsize_candidate(
_ => bug!("source: {source}, target: {target}"),
};
Ok(ImplSourceBuiltinData { nested })
Ok(nested)
}
fn confirm_const_destruct_candidate(
&mut self,
obligation: &TraitObligation<'tcx>,
impl_def_id: Option<DefId>,
) -> Result<ImplSourceConstDestructData<PredicateObligation<'tcx>>, SelectionError<'tcx>> {
) -> Result<Vec<PredicateObligation<'tcx>>, SelectionError<'tcx>> {
// `~const Destruct` in a non-const environment is always trivially true, since our type is `Drop`
if !obligation.is_const() {
return Ok(ImplSourceConstDestructData { nested: vec![] });
return Ok(vec![]);
}
let drop_trait = self.tcx().require_lang_item(LangItem::Drop, None);
@ -1381,6 +1380,6 @@ fn confirm_const_destruct_candidate(
}
}
Ok(ImplSourceConstDestructData { nested })
Ok(nested)
}
}

4
compiler/rustc_trait_selection/src/traits/util.rs
View File

@ -243,12 +243,12 @@ pub fn upcast_choices<'tcx>(
/// `object.upcast_trait_ref`) within the vtable for `object`.
pub fn get_vtable_index_of_object_method<'tcx, N>(
tcx: TyCtxt<'tcx>,
object: &super::ImplSourceObjectData<'tcx, N>,
object: &super::ImplSourceObjectData<N>,
method_def_id: DefId,
) -> Option<usize> {
// Count number of methods preceding the one we are selecting and
// add them to the total offset.
tcx.own_existential_vtable_entries(object.upcast_trait_ref.def_id())
tcx.own_existential_vtable_entries(object.upcast_trait_def_id)
.iter()
.copied()
.position(|def_id| def_id == method_def_id)

145
compiler/rustc_ty_utils/src/instance.rs
View File

@ -177,85 +177,6 @@ fn resolve_associated_item<'tcx>(
Some(ty::Instance::new(leaf_def.item.def_id, substs))
}
traits::ImplSource::Generator(generator_data) => {
if cfg!(debug_assertions) && tcx.item_name(trait_item_id) != sym::resume {
// For compiler developers who'd like to add new items to `Generator`,
// you either need to generate a shim body, or perhaps return
// `InstanceDef::Item` pointing to a trait default method body if
// it is given a default implementation by the trait.
span_bug!(
tcx.def_span(generator_data.generator_def_id),
"no definition for `{trait_ref}::{}` for built-in generator type",
tcx.item_name(trait_item_id)
)
}
Some(Instance {
def: ty::InstanceDef::Item(generator_data.generator_def_id),
substs: generator_data.substs,
})
}
traits::ImplSource::Future(future_data) => {
if Some(trait_item_id) == tcx.lang_items().future_poll_fn() {
// `Future::poll` is generated by the compiler.
Some(Instance {
def: ty::InstanceDef::Item(future_data.generator_def_id),
substs: future_data.substs,
})
} else {
// All other methods are default methods of the `Future` trait.
// (this assumes that `ImplSource::Future` is only used for methods on `Future`)
debug_assert!(tcx.defaultness(trait_item_id).has_value());
Some(Instance::new(trait_item_id, rcvr_substs))
}
}
traits::ImplSource::Closure(closure_data) => {
if cfg!(debug_assertions)
&& ![sym::call, sym::call_mut, sym::call_once]
.contains(&tcx.item_name(trait_item_id))
{
// For compiler developers who'd like to add new items to `Fn`/`FnMut`/`FnOnce`,
// you either need to generate a shim body, or perhaps return
// `InstanceDef::Item` pointing to a trait default method body if
// it is given a default implementation by the trait.
span_bug!(
tcx.def_span(closure_data.closure_def_id),
"no definition for `{trait_ref}::{}` for built-in closure type",
tcx.item_name(trait_item_id)
)
}
let trait_closure_kind = tcx.fn_trait_kind_from_def_id(trait_id).unwrap();
Instance::resolve_closure(
tcx,
closure_data.closure_def_id,
closure_data.substs,
trait_closure_kind,
)
}
traits::ImplSource::FnPointer(ref data) => match data.fn_ty.kind() {
ty::FnDef(..) | ty::FnPtr(..) => {
if cfg!(debug_assertions)
&& ![sym::call, sym::call_mut, sym::call_once]
.contains(&tcx.item_name(trait_item_id))
{
// For compiler developers who'd like to add new items to `Fn`/`FnMut`/`FnOnce`,
// you either need to generate a shim body, or perhaps return
// `InstanceDef::Item` pointing to a trait default method body if
// it is given a default implementation by the trait.
bug!(
"no definition for `{trait_ref}::{}` for built-in fn type",
tcx.item_name(trait_item_id)
)
}
Some(Instance {
def: ty::InstanceDef::FnPtrShim(trait_item_id, data.fn_ty),
substs: rcvr_substs,
})
}
_ => bug!(
"no built-in definition for `{trait_ref}::{}` for non-fn type",
tcx.item_name(trait_item_id)
),
},
traits::ImplSource::Object(ref data) => {
traits::get_vtable_index_of_object_method(tcx, data, trait_item_id).map(|index| {
Instance {
@ -308,15 +229,73 @@ fn resolve_associated_item<'tcx>(
span: tcx.def_span(trait_item_id),
})
}
} else if Some(trait_ref.def_id) == lang_items.future_trait() {
let ty::Generator(generator_def_id, substs, _) = *rcvr_substs.type_at(0).kind() else {
bug!()
};
if Some(trait_item_id) == tcx.lang_items().future_poll_fn() {
// `Future::poll` is generated by the compiler.
Some(Instance { def: ty::InstanceDef::Item(generator_def_id), substs: substs })
} else {
// All other methods are default methods of the `Future` trait.
// (this assumes that `ImplSource::Builtin` is only used for methods on `Future`)
debug_assert!(tcx.defaultness(trait_item_id).has_value());
Some(Instance::new(trait_item_id, rcvr_substs))
}
} else if Some(trait_ref.def_id) == lang_items.gen_trait() {
let ty::Generator(generator_def_id, substs, _) = *rcvr_substs.type_at(0).kind() else {
bug!()
};
if cfg!(debug_assertions) && tcx.item_name(trait_item_id) != sym::resume {
// For compiler developers who'd like to add new items to `Generator`,
// you either need to generate a shim body, or perhaps return
// `InstanceDef::Item` pointing to a trait default method body if
// it is given a default implementation by the trait.
span_bug!(
tcx.def_span(generator_def_id),
"no definition for `{trait_ref}::{}` for built-in generator type",
tcx.item_name(trait_item_id)
)
}
Some(Instance { def: ty::InstanceDef::Item(generator_def_id), substs })
} else if tcx.fn_trait_kind_from_def_id(trait_ref.def_id).is_some() {
// FIXME: This doesn't check for malformed libcore that defines, e.g.,
// `trait Fn { fn call_once(&self) { .. } }`. This is mostly for extension
// methods.
if cfg!(debug_assertions)
&& ![sym::call, sym::call_mut, sym::call_once]
.contains(&tcx.item_name(trait_item_id))
{
// For compiler developers who'd like to add new items to `Fn`/`FnMut`/`FnOnce`,
// you either need to generate a shim body, or perhaps return
// `InstanceDef::Item` pointing to a trait default method body if
// it is given a default implementation by the trait.
bug!(
"no definition for `{trait_ref}::{}` for built-in callable type",
tcx.item_name(trait_item_id)
)
}
match *rcvr_substs.type_at(0).kind() {
ty::Closure(closure_def_id, substs) => {
let trait_closure_kind = tcx.fn_trait_kind_from_def_id(trait_id).unwrap();
Instance::resolve_closure(tcx, closure_def_id, substs, trait_closure_kind)
}
ty::FnDef(..) | ty::FnPtr(..) => Some(Instance {
def: ty::InstanceDef::FnPtrShim(trait_item_id, rcvr_substs.type_at(0)),
substs: rcvr_substs,
}),
_ => bug!(
"no built-in definition for `{trait_ref}::{}` for non-fn type",
tcx.item_name(trait_item_id)
),
}
} else {
None
}
}
traits::ImplSource::AutoImpl(..)
| traits::ImplSource::Param(..)
traits::ImplSource::Param(..)
| traits::ImplSource::TraitAlias(..)
| traits::ImplSource::TraitUpcasting(_)
| traits::ImplSource::ConstDestruct(_) => None,
| traits::ImplSource::TraitUpcasting(_) => None,
})
}