mathieu/os-rust
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Fully implement ConstArgHasType

Browse source
This commit is contained in:
Boxy 2024-06-03 03:11:11 +01:00
parent a9702a6668
commit 8d6705cdb8
7 changed files with 158 additions and 103 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
compiler/rustc_middle/src/traits/mod.rs
View file

@ -616,6 +616,8 @@ pub enum SelectionError<'tcx> {
/// We can thus not know whether the hidden type implements an auto trait, so
/// we should not presume anything about it.
OpaqueTypeAutoTraitLeakageUnknown(DefId),
/// Error for a `ConstArgHasType` goal
ConstArgHasWrongType { ct: ty::Const<'tcx>, ct_ty: Ty<'tcx>, expected_ty: Ty<'tcx> },
}
#[derive(Clone, Debug, TypeVisitable)]

24
compiler/rustc_middle/src/ty/mod.rs
View file

@ -934,6 +934,30 @@ pub struct Placeholder<T> {
pub universe: UniverseIndex,
pub bound: T,
}
impl Placeholder<BoundVar> {
pub fn find_const_ty_from_env<'tcx>(self, env: ParamEnv<'tcx>) -> Ty<'tcx> {
let mut candidates = env.caller_bounds().iter().filter_map(|clause| {
// `ConstArgHasType` are never desugared to be higher ranked.
match clause.kind().skip_binder() {
ty::ClauseKind::ConstArgHasType(placeholder_ct, ty) => {
assert!(!(placeholder_ct, ty).has_escaping_bound_vars());
match placeholder_ct.kind() {
ty::ConstKind::Placeholder(placeholder_ct) if placeholder_ct == self => {
Some(ty)
}
_ => None,
}
}
_ => None,
}
});
let ty = candidates.next().unwrap();
assert!(candidates.next().is_none());
ty
}
}
pub type PlaceholderRegion = Placeholder<BoundRegion>;

22
compiler/rustc_middle/src/ty/sty.rs
View file

@ -21,6 +21,7 @@ use rustc_span::symbol::{sym, Symbol};
use rustc_span::{Span, DUMMY_SP};
use rustc_target::abi::{FieldIdx, VariantIdx, FIRST_VARIANT};
use rustc_target::spec::abi;
use rustc_type_ir::visit::TypeVisitableExt;
use std::assert_matches::debug_assert_matches;
use std::borrow::Cow;
use std::iter;
@ -339,6 +340,27 @@ impl ParamConst {
pub fn for_def(def: &ty::GenericParamDef) -> ParamConst {
ParamConst::new(def.index, def.name)
}
pub fn find_ty_from_env<'tcx>(self, env: ParamEnv<'tcx>) -> Ty<'tcx> {
let mut candidates = env.caller_bounds().iter().filter_map(|clause| {
// `ConstArgHasType` are never desugared to be higher ranked.
match clause.kind().skip_binder() {
ty::ClauseKind::ConstArgHasType(param_ct, ty) => {
assert!(!(param_ct, ty).has_escaping_bound_vars());
match param_ct.kind() {
ty::ConstKind::Param(param_ct) if param_ct.index == self.index => Some(ty),
_ => None,
}
}
_ => None,
}
});
let ty = candidates.next().unwrap();
assert!(candidates.next().is_none());
ty
}
}
#[derive(Clone, Copy, PartialEq, Eq, Hash, TyEncodable, TyDecodable)]

41
compiler/rustc_trait_selection/src/solve/mod.rs
View file

@ -200,30 +200,37 @@ impl<'a, 'tcx> EvalCtxt<'a, InferCtxt<'tcx>> {
) -> QueryResult<'tcx> {
let (ct, ty) = goal.predicate;
// FIXME(BoxyUwU): Really we should not be calling `ct.ty()` for any variant
// other than `ConstKind::Value`. Unfortunately this would require looking in the
// env for any `ConstArgHasType` assumptions for parameters and placeholders. I
// have not yet gotten around to implementing this though.
//
// We do still stall on infer vars though as otherwise a goal like:
// `ConstArgHasType(?x: usize, usize)` can succeed even though it might later
// get unified with some const that is not of type `usize`.
match ct.kind() {
let ct_ty = match ct.kind() {
// FIXME: Ignore effect vars because canonicalization doesn't handle them correctly
// and if we stall on the var then we wind up creating ambiguity errors in a probe
// for this goal which contains an effect var. Which then ends up ICEing.
ty::ConstKind::Infer(ty::InferConst::Var(_)) => {
self.evaluate_added_goals_and_make_canonical_response(Certainty::AMBIGUOUS)
ty::ConstKind::Infer(ty::InferConst::EffectVar(_)) => {
return self.evaluate_added_goals_and_make_canonical_response(Certainty::Yes);
}
ty::ConstKind::Infer(_) => {
return self.evaluate_added_goals_and_make_canonical_response(Certainty::AMBIGUOUS);
}
ty::ConstKind::Error(_) => {
self.evaluate_added_goals_and_make_canonical_response(Certainty::Yes)
return self.evaluate_added_goals_and_make_canonical_response(Certainty::Yes);
}
_ => {
// THISPR
self.eq(goal.param_env, todo!(), ty)?;
self.evaluate_added_goals_and_make_canonical_response(Certainty::Yes)
ty::ConstKind::Unevaluated(uv) => {
self.interner().type_of(uv.def).instantiate(self.interner(), uv.args)
}
}
ty::ConstKind::Expr(_) => unimplemented!(
"`feature(generic_const_exprs)` is not supported in the new trait solver"
),
ty::ConstKind::Param(_) => {
unreachable!("`ConstKind::Param` should have been canonicalized to `Placeholder`")
}
ty::ConstKind::Bound(_, _) => bug!("escaping bound vars in {:?}", ct),
ty::ConstKind::Value(ty, _) => ty,
ty::ConstKind::Placeholder(placeholder) => {
placeholder.find_const_ty_from_env(goal.param_env)
}
};
self.eq(goal.param_env, ct_ty, ty)?;
self.evaluate_added_goals_and_make_canonical_response(Certainty::Yes)
}
}

78
compiler/rustc_trait_selection/src/traits/error_reporting/type_err_ctxt_ext.rs
View file

@ -876,57 +876,25 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
}
}
ty::PredicateKind::Clause(ty::ClauseKind::ConstEvaluatable(..)) => {
// Errors for `ConstEvaluatable` predicates show up as
// `SelectionError::ConstEvalFailure`,
// not `Unimplemented`.
// Errors for `ConstEvaluatable` predicates show up as
// `SelectionError::ConstEvalFailure`,
// not `Unimplemented`.
ty::PredicateKind::Clause(ty::ClauseKind::ConstEvaluatable(..))
// Errors for `ConstEquate` predicates show up as
// `SelectionError::ConstEvalFailure`,
// not `Unimplemented`.
| ty::PredicateKind::ConstEquate { .. }
// Ambiguous predicates should never error
| ty::PredicateKind::Ambiguous
| ty::PredicateKind::NormalizesTo { .. }
| ty::PredicateKind::AliasRelate { .. }
| ty::PredicateKind::Clause(ty::ClauseKind::ConstArgHasType { .. }) => {
span_bug!(
span,
"const-evaluatable requirement gave wrong error: `{:?}`",
"Unexpected `Predicate` for `SelectionError`: `{:?}`",
obligation
)
}
ty::PredicateKind::ConstEquate(..) => {
// Errors for `ConstEquate` predicates show up as
// `SelectionError::ConstEvalFailure`,
// not `Unimplemented`.
span_bug!(
span,
"const-equate requirement gave wrong error: `{:?}`",
obligation
)
}
ty::PredicateKind::Ambiguous => span_bug!(span, "ambiguous"),
ty::PredicateKind::NormalizesTo(..) => span_bug!(
span,
"NormalizesTo predicate should never be the predicate cause of a SelectionError"
),
ty::PredicateKind::AliasRelate(..) => span_bug!(
span,
"AliasRelate predicate should never be the predicate cause of a SelectionError"
),
ty::PredicateKind::Clause(ty::ClauseKind::ConstArgHasType(ct, ty)) => {
let mut diag = self.dcx().struct_span_err(
span,
format!("the constant `{ct}` is not of type `{ty}`"),
);
self.note_type_err(
&mut diag,
&obligation.cause,
None,
None,
// THISPR
TypeError::Sorts(ty::error::ExpectedFound::new(true, ty, todo!())),
false,
false,
);
diag
}
}
}
@ -989,6 +957,24 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
Overflow(_) => {
bug!("overflow should be handled before the `report_selection_error` path");
}
SelectionError::ConstArgHasWrongType { ct, ct_ty, expected_ty } => {
let mut diag = self.dcx().struct_span_err(
span,
format!("the constant `{ct}` is not of type `{expected_ty}`"),
);
self.note_type_err(
&mut diag,
&obligation.cause,
None,
None,
TypeError::Sorts(ty::error::ExpectedFound::new(true, expected_ty, ct_ty)),
false,
false,
);
diag
}
};
self.note_obligation_cause(&mut err, &obligation);

68
compiler/rustc_trait_selection/src/traits/fulfill.rs
View file

@ -439,38 +439,50 @@ impl<'a, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'tcx> {
// This is because this is not ever a useful obligation to report
// as the cause of an overflow.
ty::PredicateKind::Clause(ty::ClauseKind::ConstArgHasType(ct, ty)) => {
// FIXME(BoxyUwU): Really we should not be calling `ct.ty()` for any variant
// other than `ConstKind::Value`. Unfortunately this would require looking in the
// env for any `ConstArgHasType` assumptions for parameters and placeholders. I
// don't really want to implement this in the old solver so I haven't.
//
// We do still stall on infer vars though as otherwise a goal like:
// `ConstArgHasType(?x: usize, usize)` can succeed even though it might later
// get unified with some const that is not of type `usize`.
let ct = self.selcx.infcx.shallow_resolve_const(ct);
match ct.kind() {
ty::ConstKind::Infer(ty::InferConst::Var(vid)) => {
let ct = infcx.shallow_resolve_const(ct);
let ct_ty = match ct.kind() {
ty::ConstKind::Infer(var) => {
let var = match var {
ty::InferConst::Var(vid) => TyOrConstInferVar::Const(vid),
ty::InferConst::EffectVar(vid) => TyOrConstInferVar::Effect(vid),
ty::InferConst::Fresh(_) => {
bug!("encountered fresh const in fulfill")
}
};
pending_obligation.stalled_on.clear();
pending_obligation.stalled_on.extend([TyOrConstInferVar::Const(vid)]);
ProcessResult::Unchanged
pending_obligation.stalled_on.extend([var]);
return ProcessResult::Unchanged;
}
ty::ConstKind::Error(_) => return ProcessResult::Changed(vec![]),
_ => {
match self.selcx.infcx.at(&obligation.cause, obligation.param_env).eq(
// Only really excercised by generic_const_exprs
DefineOpaqueTypes::Yes,
// THISPR
todo!(),
ty,
) {
Ok(inf_ok) => {
ProcessResult::Changed(mk_pending(inf_ok.into_obligations()))
}
Err(_) => ProcessResult::Error(FulfillmentErrorCode::Select(
SelectionError::Unimplemented,
)),
}
ty::ConstKind::Value(ty, _) => ty,
ty::ConstKind::Unevaluated(uv) => {
infcx.tcx.type_of(uv.def).instantiate(infcx.tcx, uv.args)
}
// FIXME(generic_const_exprs): we should construct an alias like
// `<lhs_ty as Add<rhs_ty>>::Output` when this is an `Expr` representing
// `lhs + rhs`.
ty::ConstKind::Expr(_) => {
return ProcessResult::Changed(mk_pending(vec![]));
}
ty::ConstKind::Placeholder(_) => {
bug!("placeholder const {:?} in old solver", ct)
}
ty::ConstKind::Bound(_, _) => bug!("escaping bound vars in {:?}", ct),
ty::ConstKind::Param(param_ct) => {
param_ct.find_ty_from_env(obligation.param_env)
}
};
match infcx.at(&obligation.cause, obligation.param_env).eq(
// Only really excercised by generic_const_exprs
DefineOpaqueTypes::Yes,
ct_ty,
ty,
) {
Ok(inf_ok) => ProcessResult::Changed(mk_pending(inf_ok.into_obligations())),
Err(_) => ProcessResult::Error(FulfillmentErrorCode::Select(
SelectionError::ConstArgHasWrongType { ct, ct_ty, expected_ty: ty },
)),
}
}

26
compiler/rustc_trait_selection/src/traits/select/mod.rs
View file

@ -994,23 +994,25 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
}
ty::PredicateKind::Ambiguous => Ok(EvaluatedToAmbig),
ty::PredicateKind::Clause(ty::ClauseKind::ConstArgHasType(ct, ty)) => {
// FIXME(BoxyUwU): Really we should not be calling `ct.ty()` for any variant
// other than `ConstKind::Value`. Unfortunately this would require looking in the
// env for any `ConstArgHasType` assumptions for parameters and placeholders. I
// don't really want to implement this in the old solver so I haven't.
//
// We do still stall on infer vars though as otherwise a goal like:
// `ConstArgHasType(?x: usize, usize)` can succeed even though it might later
// get unified with some const that is not of type `usize`.
let ct = self.infcx.shallow_resolve_const(ct);
let ct_ty = match ct.kind() {
ty::ConstKind::Infer(ty::InferConst::Var(_)) => {
ty::ConstKind::Infer(_) => {
return Ok(EvaluatedToAmbig);
}
ty::ConstKind::Error(_) => return Ok(EvaluatedToOk),
// THISPR
_ => todo!(),
// _ => ct.ty(),
ty::ConstKind::Value(ty, _) => ty,
ty::ConstKind::Unevaluated(uv) => {
self.tcx().type_of(uv.def).instantiate(self.tcx(), uv.args)
}
// FIXME(generic_const_exprs): See comment in `fulfill.rs`
ty::ConstKind::Expr(_) => return Ok(EvaluatedToOk),
ty::ConstKind::Placeholder(_) => {
bug!("placeholder const {:?} in old solver", ct)
}
ty::ConstKind::Bound(_, _) => bug!("escaping bound vars in {:?}", ct),
ty::ConstKind::Param(param_ct) => {
param_ct.find_ty_from_env(obligation.param_env)
}
};
match self.infcx.at(&obligation.cause, obligation.param_env).eq(