Rollup merge of #124918 - nnethercote:FIXME-lcnr, r=lcnr

Eliminate some `FIXME(lcnr)` comments

In some cases this involved changing code. In some cases the comment was able to removed or replaced.

r? ``@lcnr``
This commit is contained in:
Matthias Krüger 2024-05-10 07:30:20 +02:00 committed by GitHub
commit 7e4f6082ce
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8 changed files with 12 additions and 51 deletions

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@ -26,9 +26,7 @@ pub fn renumber_mir<'tcx>(
renumberer.visit_body(body);
}
// FIXME(@lcnr): A lot of these variants overlap and it seems like
// this type is only used to decide which region should be used
// as representative. This should be cleaned up.
// The fields are used only for debugging output in `sccs_info`.
#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
pub(crate) enum RegionCtxt {
Location(Location),

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@ -69,16 +69,8 @@ impl<'a> DescriptionCtx<'a> {
ty::RePlaceholder(_) | ty::ReError(_) => return None,
// FIXME(#13998) RePlaceholder should probably print like
// ReLateParam rather than dumping Debug output on the user.
//
// We shouldn't really be having unification failures with ReVar
// and ReBound though.
//
// FIXME(@lcnr): figure out why we have to handle `ReBound`
// here, this feels somewhat off.
ty::ReVar(_) | ty::ReBound(..) | ty::ReErased => {
(alt_span, "revar", format!("{region:?}"))
bug!("unexpected region for DescriptionCtx: {:?}", region);
}
};
Some(DescriptionCtx { span, kind, arg })

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@ -172,11 +172,9 @@ pub(super) fn note_and_explain_region<'tcx>(
ty::ReError(_) => return,
// We shouldn't really be having unification failures with ReVar
// and ReBound though.
//
// FIXME(@lcnr): Figure out whether this is reachable and if so, why.
ty::ReVar(_) | ty::ReBound(..) | ty::ReErased => (format!("lifetime `{region}`"), alt_span),
ty::ReVar(_) | ty::ReBound(..) | ty::ReErased => {
bug!("unexpected region for note_and_explain_region: {:?}", region);
}
};
emit_msg_span(err, prefix, description, span, suffix);

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@ -528,8 +528,8 @@ pub enum RegionVariableOrigin {
/// Region variables created as the values for early-bound regions.
///
/// FIXME(@lcnr): This can also store a `DefId`, similar to
/// `TypeVariableOriginKind::TypeParameterDefinition`.
/// FIXME(@lcnr): This should also store a `DefId`, similar to
/// `TypeVariableOrigin`.
RegionParameterDefinition(Span, Symbol),
/// Region variables created when instantiating a binder with

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@ -100,8 +100,7 @@ impl<'tcx> TyCtxt<'tcx> {
/// codegen, we need to normalize the contents.
// FIXME(@lcnr): This method should not be necessary, we now normalize
// inside of binders. We should be able to only use
// `tcx.instantiate_bound_regions_with_erased`. Same for the `try_X`
// variant.
// `tcx.instantiate_bound_regions_with_erased`.
#[tracing::instrument(level = "debug", skip(self, param_env))]
pub fn normalize_erasing_late_bound_regions<T>(
self,
@ -115,26 +114,6 @@ impl<'tcx> TyCtxt<'tcx> {
self.normalize_erasing_regions(param_env, value)
}
/// If you have a `Binder<'tcx, T>`, you can do this to strip out the
/// late-bound regions and then normalize the result, yielding up
/// a `T` (with regions erased). This is appropriate when the
/// binder is being instantiated at the call site.
///
/// N.B., currently, higher-ranked type bounds inhibit
/// normalization. Therefore, each time we erase them in
/// codegen, we need to normalize the contents.
pub fn try_normalize_erasing_late_bound_regions<T>(
self,
param_env: ty::ParamEnv<'tcx>,
value: ty::Binder<'tcx, T>,
) -> Result<T, NormalizationError<'tcx>>
where
T: TypeFoldable<TyCtxt<'tcx>>,
{
let value = self.instantiate_bound_regions_with_erased(value);
self.try_normalize_erasing_regions(param_env, value)
}
/// Monomorphizes a type from the AST by first applying the
/// in-scope instantiations and then normalizing any associated
/// types.

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@ -3443,8 +3443,6 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
self.dcx().try_steal_replace_and_emit_err(self.tcx.def_span(def_id), StashKey::Cycle, err)
}
// FIXME(@lcnr): This function could be changed to trait `TraitRef` directly
// instead of using a `Binder`.
fn report_signature_mismatch_error(
&self,
obligation: &PredicateObligation<'tcx>,

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@ -693,7 +693,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
let vtable_base = vtable_trait_first_method_offset(
tcx,
(unnormalized_upcast_trait_ref, ty::Binder::dummy(object_trait_ref)),
unnormalized_upcast_trait_ref,
ty::Binder::dummy(object_trait_ref),
);
Ok(ImplSource::Builtin(BuiltinImplSource::Object { vtable_base: vtable_base }, nested))

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@ -320,16 +320,11 @@ fn vtable_entries<'tcx>(
}
/// Find slot base for trait methods within vtable entries of another trait
// FIXME(@lcnr): This isn't a query, so why does it take a tuple as its argument.
pub(super) fn vtable_trait_first_method_offset<'tcx>(
tcx: TyCtxt<'tcx>,
key: (
ty::PolyTraitRef<'tcx>, // trait_to_be_found
ty::PolyTraitRef<'tcx>, // trait_owning_vtable
),
trait_to_be_found: ty::PolyTraitRef<'tcx>,
trait_owning_vtable: ty::PolyTraitRef<'tcx>,
) -> usize {
let (trait_to_be_found, trait_owning_vtable) = key;
// #90177
let trait_to_be_found_erased = tcx.erase_regions(trait_to_be_found);