bjoernager/rust
bjoernager/rust
1
Fork 0
Code Issues Pull requests Activity

Implement selection in new trait solver

Browse source
This commit is contained in:
Michael Goulet 2023-06-21 01:22:43 +00:00
parent f798ada7ba
commit 298c0d1a62
7 changed files with 356 additions and 21 deletions
Download patch file Download diff file Expand all files Collapse all files

51
compiler/rustc_trait_selection/src/solve/assembly/mod.rs
View file

@ -49,7 +49,7 @@ pub(super) enum CandidateSource {
/// Notable examples are auto traits, `Sized`, and `DiscriminantKind`.
/// For a list of all traits with builtin impls, check out the
/// [`EvalCtxt::assemble_builtin_impl_candidates`] method. Not
BuiltinImpl,
BuiltinImpl(BuiltinImplSource),
/// An assumption from the environment.
///
/// More precisely we've used the `n-th` assumption in the `param_env`.
@ -87,6 +87,16 @@ pub(super) enum CandidateSource {
AliasBound,
}
/// Records additional information about what kind of built-in impl this is.
/// This should only be used by selection.
#[derive(Debug, Clone, Copy)]
pub(super) enum BuiltinImplSource {
TraitUpcasting,
Object,
Misc,
Ambiguity,
}
/// Methods used to assemble candidates for either trait or projection goals.
pub(super) trait GoalKind<'tcx>:
TypeFoldable<TyCtxt<'tcx>> + Copy + Eq + std::fmt::Display
@ -295,7 +305,7 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
// least structurally resolve the type one layer.
if goal.predicate.self_ty().is_ty_var() {
return vec![Candidate {
source: CandidateSource::BuiltinImpl,
source: CandidateSource::BuiltinImpl(BuiltinImplSource::Ambiguity),
result: self
.evaluate_added_goals_and_make_canonical_response(Certainty::AMBIGUOUS)
.unwrap(),
@ -344,7 +354,10 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
let result = ecx.evaluate_added_goals_and_make_canonical_response(
Certainty::Maybe(MaybeCause::Overflow),
)?;
Ok(vec![Candidate { source: CandidateSource::BuiltinImpl, result }])
Ok(vec![Candidate {
source: CandidateSource::BuiltinImpl(BuiltinImplSource::Ambiguity),
result,
}])
},
|ecx| {
let normalized_ty = ecx.next_ty_infer();
@ -447,9 +460,10 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
};
match result {
Ok(result) => {
candidates.push(Candidate { source: CandidateSource::BuiltinImpl, result })
}
Ok(result) => candidates.push(Candidate {
source: CandidateSource::BuiltinImpl(BuiltinImplSource::Misc),
result,
}),
Err(NoSolution) => (),
}
@ -457,7 +471,10 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
// `trait Foo: Bar<A> + Bar<B>` and `dyn Foo: Unsize<dyn Bar<_>>`
if lang_items.unsize_trait() == Some(trait_def_id) {
for result in G::consider_builtin_dyn_upcast_candidates(self, goal) {
candidates.push(Candidate { source: CandidateSource::BuiltinImpl, result });
candidates.push(Candidate {
source: CandidateSource::BuiltinImpl(BuiltinImplSource::TraitUpcasting),
result,
});
}
}
}
@ -621,9 +638,10 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
};
match result {
Ok(result) => {
candidates.push(Candidate { source: CandidateSource::BuiltinImpl, result })
}
Ok(result) => candidates.push(Candidate {
source: CandidateSource::BuiltinImpl(BuiltinImplSource::Misc),
result,
}),
Err(NoSolution) => (),
}
}
@ -688,9 +706,10 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
}
match G::consider_object_bound_candidate(self, goal, assumption) {
Ok(result) => {
candidates.push(Candidate { source: CandidateSource::BuiltinImpl, result })
}
Ok(result) => candidates.push(Candidate {
source: CandidateSource::BuiltinImpl(BuiltinImplSource::Object),
result,
}),
Err(NoSolution) => (),
}
}
@ -711,8 +730,10 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
Err(_) => match self
.evaluate_added_goals_and_make_canonical_response(Certainty::AMBIGUOUS)
{
Ok(result) => candidates
.push(Candidate { source: CandidateSource::BuiltinImpl, result }),
Ok(result) => candidates.push(Candidate {
source: CandidateSource::BuiltinImpl(BuiltinImplSource::Ambiguity),
result,
}),
// FIXME: This will be reachable at some point if we're in
// `assemble_candidates_after_normalizing_self_ty` and we get a
// universe error. We'll deal with it at this point.