};
use rustc_middle::ty::{GenericParamDefKind, ToPredicate, TyCtxt};
use rustc_span::Span;
-use rustc_trait_selection::traits::error_reporting::InferCtxtExt;
+use rustc_trait_selection::traits::error_reporting::TypeErrCtxtExt;
use rustc_trait_selection::traits::outlives_bounds::InferCtxtExt as _;
use rustc_trait_selection::traits::{
self, ObligationCause, ObligationCauseCode, ObligationCtxt, Reveal,
);
let param_env = traits::normalize_param_env_or_error(tcx, param_env, normalize_cause);
- tcx.infer_ctxt().enter(|ref infcx| {
- let ocx = ObligationCtxt::new(infcx);
+ let infcx = &tcx.infer_ctxt().build();
+ let ocx = ObligationCtxt::new(infcx);
- debug!("compare_impl_method: caller_bounds={:?}", param_env.caller_bounds());
+ debug!("compare_impl_method: caller_bounds={:?}", param_env.caller_bounds());
- let mut selcx = traits::SelectionContext::new(&infcx);
- let impl_m_own_bounds = impl_m_predicates.instantiate_own(tcx, impl_to_placeholder_substs);
- for (predicate, span) in iter::zip(impl_m_own_bounds.predicates, impl_m_own_bounds.spans) {
- let normalize_cause = traits::ObligationCause::misc(span, impl_m_hir_id);
- let traits::Normalized { value: predicate, obligations } =
- traits::normalize(&mut selcx, param_env, normalize_cause, predicate);
+ let mut selcx = traits::SelectionContext::new(&infcx);
+ let impl_m_own_bounds = impl_m_predicates.instantiate_own(tcx, impl_to_placeholder_substs);
+ for (predicate, span) in iter::zip(impl_m_own_bounds.predicates, impl_m_own_bounds.spans) {
+ let normalize_cause = traits::ObligationCause::misc(span, impl_m_hir_id);
+ let traits::Normalized { value: predicate, obligations } =
+ traits::normalize(&mut selcx, param_env, normalize_cause, predicate);
- ocx.register_obligations(obligations);
- let cause = ObligationCause::new(
- span,
- impl_m_hir_id,
- ObligationCauseCode::CompareImplItemObligation {
- impl_item_def_id: impl_m.def_id.expect_local(),
- trait_item_def_id: trait_m.def_id,
- kind: impl_m.kind,
- },
- );
- ocx.register_obligation(traits::Obligation::new(cause, param_env, predicate));
- }
-
- // We now need to check that the signature of the impl method is
- // compatible with that of the trait method. We do this by
- // checking that `impl_fty <: trait_fty`.
- //
- // FIXME. Unfortunately, this doesn't quite work right now because
- // associated type normalization is not integrated into subtype
- // checks. For the comparison to be valid, we need to
- // normalize the associated types in the impl/trait methods
- // first. However, because function types bind regions, just
- // calling `normalize_associated_types_in` would have no effect on
- // any associated types appearing in the fn arguments or return
- // type.
-
- // Compute placeholder form of impl and trait method tys.
- let tcx = infcx.tcx;
-
- let mut wf_tys = FxHashSet::default();
-
- let impl_sig = infcx.replace_bound_vars_with_fresh_vars(
- impl_m_span,
- infer::HigherRankedType,
- tcx.fn_sig(impl_m.def_id),
+ ocx.register_obligations(obligations);
+ let cause = ObligationCause::new(
+ span,
+ impl_m_hir_id,
+ ObligationCauseCode::CompareImplItemObligation {
+ impl_item_def_id: impl_m.def_id.expect_local(),
+ trait_item_def_id: trait_m.def_id,
+ kind: impl_m.kind,
+ },
);
+ ocx.register_obligation(traits::Obligation::new(cause, param_env, predicate));
+ }
- let norm_cause = ObligationCause::misc(impl_m_span, impl_m_hir_id);
- let impl_sig = ocx.normalize(norm_cause.clone(), param_env, impl_sig);
- let impl_fty = tcx.mk_fn_ptr(ty::Binder::dummy(impl_sig));
- debug!("compare_impl_method: impl_fty={:?}", impl_fty);
-
- let trait_sig = tcx.bound_fn_sig(trait_m.def_id).subst(tcx, trait_to_placeholder_substs);
- let trait_sig = tcx.liberate_late_bound_regions(impl_m.def_id, trait_sig);
-
- // Next, add all inputs and output as well-formed tys. Importantly,
- // we have to do this before normalization, since the normalized ty may
- // not contain the input parameters. See issue #87748.
- wf_tys.extend(trait_sig.inputs_and_output.iter());
- let trait_sig = ocx.normalize(norm_cause, param_env, trait_sig);
- // We also have to add the normalized trait signature
- // as we don't normalize during implied bounds computation.
- wf_tys.extend(trait_sig.inputs_and_output.iter());
- let trait_fty = tcx.mk_fn_ptr(ty::Binder::dummy(trait_sig));
-
- debug!("compare_impl_method: trait_fty={:?}", trait_fty);
-
- // FIXME: We'd want to keep more accurate spans than "the method signature" when
- // processing the comparison between the trait and impl fn, but we sadly lose them
- // and point at the whole signature when a trait bound or specific input or output
- // type would be more appropriate. In other places we have a `Vec<Span>`
- // corresponding to their `Vec<Predicate>`, but we don't have that here.
- // Fixing this would improve the output of test `issue-83765.rs`.
- let mut result = infcx
- .at(&cause, param_env)
- .sup(trait_fty, impl_fty)
- .map(|infer_ok| ocx.register_infer_ok_obligations(infer_ok));
-
- // HACK(RPITIT): #101614. When we are trying to infer the hidden types for
- // RPITITs, we need to equate the output tys instead of just subtyping. If
- // we just use `sup` above, we'll end up `&'static str <: _#1t`, which causes
- // us to infer `_#1t = #'_#2r str`, where `'_#2r` is unconstrained, which gets
- // fixed up to `ReEmpty`, and which is certainly not what we want.
- if trait_fty.has_infer_types() {
- result = result.and_then(|()| {
- infcx
- .at(&cause, param_env)
- .eq(trait_sig.output(), impl_sig.output())
- .map(|infer_ok| ocx.register_infer_ok_obligations(infer_ok))
- });
- }
+ // We now need to check that the signature of the impl method is
+ // compatible with that of the trait method. We do this by
+ // checking that `impl_fty <: trait_fty`.
+ //
+ // FIXME. Unfortunately, this doesn't quite work right now because
+ // associated type normalization is not integrated into subtype
+ // checks. For the comparison to be valid, we need to
+ // normalize the associated types in the impl/trait methods
+ // first. However, because function types bind regions, just
+ // calling `normalize_associated_types_in` would have no effect on
+ // any associated types appearing in the fn arguments or return
+ // type.
+
+ // Compute placeholder form of impl and trait method tys.
+ let tcx = infcx.tcx;
- if let Err(terr) = result {
- debug!("sub_types failed: impl ty {:?}, trait ty {:?}", impl_fty, trait_fty);
+ let mut wf_tys = FxHashSet::default();
- let (impl_err_span, trait_err_span) =
- extract_spans_for_error_reporting(&infcx, terr, &cause, impl_m, trait_m);
+ let impl_sig = infcx.replace_bound_vars_with_fresh_vars(
+ impl_m_span,
+ infer::HigherRankedType,
+ tcx.fn_sig(impl_m.def_id),
+ );
- cause.span = impl_err_span;
+ let norm_cause = ObligationCause::misc(impl_m_span, impl_m_hir_id);
+ let impl_sig = ocx.normalize(norm_cause.clone(), param_env, impl_sig);
+ let impl_fty = tcx.mk_fn_ptr(ty::Binder::dummy(impl_sig));
+ debug!("compare_impl_method: impl_fty={:?}", impl_fty);
+
+ let trait_sig = tcx.bound_fn_sig(trait_m.def_id).subst(tcx, trait_to_placeholder_substs);
+ let trait_sig = tcx.liberate_late_bound_regions(impl_m.def_id, trait_sig);
+
+ // Next, add all inputs and output as well-formed tys. Importantly,
+ // we have to do this before normalization, since the normalized ty may
+ // not contain the input parameters. See issue #87748.
+ wf_tys.extend(trait_sig.inputs_and_output.iter());
+ let trait_sig = ocx.normalize(norm_cause, param_env, trait_sig);
+ // We also have to add the normalized trait signature
+ // as we don't normalize during implied bounds computation.
+ wf_tys.extend(trait_sig.inputs_and_output.iter());
+ let trait_fty = tcx.mk_fn_ptr(ty::Binder::dummy(trait_sig));
+
+ debug!("compare_impl_method: trait_fty={:?}", trait_fty);
+
+ // FIXME: We'd want to keep more accurate spans than "the method signature" when
+ // processing the comparison between the trait and impl fn, but we sadly lose them
+ // and point at the whole signature when a trait bound or specific input or output
+ // type would be more appropriate. In other places we have a `Vec<Span>`
+ // corresponding to their `Vec<Predicate>`, but we don't have that here.
+ // Fixing this would improve the output of test `issue-83765.rs`.
+ let mut result = infcx
+ .at(&cause, param_env)
+ .sup(trait_fty, impl_fty)
+ .map(|infer_ok| ocx.register_infer_ok_obligations(infer_ok));
+
+ // HACK(RPITIT): #101614. When we are trying to infer the hidden types for
+ // RPITITs, we need to equate the output tys instead of just subtyping. If
+ // we just use `sup` above, we'll end up `&'static str <: _#1t`, which causes
+ // us to infer `_#1t = #'_#2r str`, where `'_#2r` is unconstrained, which gets
+ // fixed up to `ReEmpty`, and which is certainly not what we want.
+ if trait_fty.has_infer_types() {
+ result = result.and_then(|()| {
+ infcx
+ .at(&cause, param_env)
+ .eq(trait_sig.output(), impl_sig.output())
+ .map(|infer_ok| ocx.register_infer_ok_obligations(infer_ok))
+ });
+ }
- let mut diag = struct_span_err!(
- tcx.sess,
- cause.span(),
- E0053,
- "method `{}` has an incompatible type for trait",
- trait_m.name
- );
- match &terr {
- TypeError::ArgumentMutability(0) | TypeError::ArgumentSorts(_, 0)
- if trait_m.fn_has_self_parameter =>
- {
- let ty = trait_sig.inputs()[0];
- let sugg = match ExplicitSelf::determine(ty, |_| ty == impl_trait_ref.self_ty())
- {
- ExplicitSelf::ByValue => "self".to_owned(),
- ExplicitSelf::ByReference(_, hir::Mutability::Not) => "&self".to_owned(),
- ExplicitSelf::ByReference(_, hir::Mutability::Mut) => {
- "&mut self".to_owned()
- }
- _ => format!("self: {ty}"),
- };
+ if let Err(terr) = result {
+ debug!("sub_types failed: impl ty {:?}, trait ty {:?}", impl_fty, trait_fty);
- // When the `impl` receiver is an arbitrary self type, like `self: Box<Self>`, the
- // span points only at the type `Box<Self`>, but we want to cover the whole
- // argument pattern and type.
- let span = match tcx.hir().expect_impl_item(impl_m.def_id.expect_local()).kind {
- ImplItemKind::Fn(ref sig, body) => tcx
- .hir()
- .body_param_names(body)
- .zip(sig.decl.inputs.iter())
- .map(|(param, ty)| param.span.to(ty.span))
- .next()
- .unwrap_or(impl_err_span),
- _ => bug!("{:?} is not a method", impl_m),
- };
+ let (impl_err_span, trait_err_span) =
+ extract_spans_for_error_reporting(&infcx, terr, &cause, impl_m, trait_m);
+ cause.span = impl_err_span;
+
+ let mut diag = struct_span_err!(
+ tcx.sess,
+ cause.span(),
+ E0053,
+ "method `{}` has an incompatible type for trait",
+ trait_m.name
+ );
+ match &terr {
+ TypeError::ArgumentMutability(0) | TypeError::ArgumentSorts(_, 0)
+ if trait_m.fn_has_self_parameter =>
+ {
+ let ty = trait_sig.inputs()[0];
+ let sugg = match ExplicitSelf::determine(ty, |_| ty == impl_trait_ref.self_ty()) {
+ ExplicitSelf::ByValue => "self".to_owned(),
+ ExplicitSelf::ByReference(_, hir::Mutability::Not) => "&self".to_owned(),
+ ExplicitSelf::ByReference(_, hir::Mutability::Mut) => "&mut self".to_owned(),
+ _ => format!("self: {ty}"),
+ };
+
+ // When the `impl` receiver is an arbitrary self type, like `self: Box<Self>`, the
+ // span points only at the type `Box<Self`>, but we want to cover the whole
+ // argument pattern and type.
+ let span = match tcx.hir().expect_impl_item(impl_m.def_id.expect_local()).kind {
+ ImplItemKind::Fn(ref sig, body) => tcx
+ .hir()
+ .body_param_names(body)
+ .zip(sig.decl.inputs.iter())
+ .map(|(param, ty)| param.span.to(ty.span))
+ .next()
+ .unwrap_or(impl_err_span),
+ _ => bug!("{:?} is not a method", impl_m),
+ };
+
+ diag.span_suggestion(
+ span,
+ "change the self-receiver type to match the trait",
+ sugg,
+ Applicability::MachineApplicable,
+ );
+ }
+ TypeError::ArgumentMutability(i) | TypeError::ArgumentSorts(_, i) => {
+ if trait_sig.inputs().len() == *i {
+ // Suggestion to change output type. We do not suggest in `async` functions
+ // to avoid complex logic or incorrect output.
+ match tcx.hir().expect_impl_item(impl_m.def_id.expect_local()).kind {
+ ImplItemKind::Fn(ref sig, _)
+ if sig.header.asyncness == hir::IsAsync::NotAsync =>
+ {
+ let msg = "change the output type to match the trait";
+ let ap = Applicability::MachineApplicable;
+ match sig.decl.output {
+ hir::FnRetTy::DefaultReturn(sp) => {
+ let sugg = format!("-> {} ", trait_sig.output());
+ diag.span_suggestion_verbose(sp, msg, sugg, ap);
+ }
+ hir::FnRetTy::Return(hir_ty) => {
+ let sugg = trait_sig.output();
+ diag.span_suggestion(hir_ty.span, msg, sugg, ap);
+ }
+ };
+ }
+ _ => {}
+ };
+ } else if let Some(trait_ty) = trait_sig.inputs().get(*i) {
diag.span_suggestion(
- span,
- "change the self-receiver type to match the trait",
- sugg,
+ impl_err_span,
+ "change the parameter type to match the trait",
+ trait_ty,
Applicability::MachineApplicable,
);
}
- TypeError::ArgumentMutability(i) | TypeError::ArgumentSorts(_, i) => {
- if trait_sig.inputs().len() == *i {
- // Suggestion to change output type. We do not suggest in `async` functions
- // to avoid complex logic or incorrect output.
- match tcx.hir().expect_impl_item(impl_m.def_id.expect_local()).kind {
- ImplItemKind::Fn(ref sig, _)
- if sig.header.asyncness == hir::IsAsync::NotAsync =>
- {
- let msg = "change the output type to match the trait";
- let ap = Applicability::MachineApplicable;
- match sig.decl.output {
- hir::FnRetTy::DefaultReturn(sp) => {
- let sugg = format!("-> {} ", trait_sig.output());
- diag.span_suggestion_verbose(sp, msg, sugg, ap);
- }
- hir::FnRetTy::Return(hir_ty) => {
- let sugg = trait_sig.output();
- diag.span_suggestion(hir_ty.span, msg, sugg, ap);
- }
- };
- }
- _ => {}
- };
- } else if let Some(trait_ty) = trait_sig.inputs().get(*i) {
- diag.span_suggestion(
- impl_err_span,
- "change the parameter type to match the trait",
- trait_ty,
- Applicability::MachineApplicable,
- );
- }
- }
- _ => {}
}
+ _ => {}
+ }
- infcx.note_type_err(
- &mut diag,
- &cause,
- trait_err_span.map(|sp| (sp, "type in trait".to_owned())),
- Some(infer::ValuePairs::Terms(ExpectedFound {
- expected: trait_fty.into(),
- found: impl_fty.into(),
- })),
- terr,
- false,
- false,
- );
+ infcx.err_ctxt().note_type_err(
+ &mut diag,
+ &cause,
+ trait_err_span.map(|sp| (sp, "type in trait".to_owned())),
+ Some(infer::ValuePairs::Terms(ExpectedFound {
+ expected: trait_fty.into(),
+ found: impl_fty.into(),
+ })),
+ terr,
+ false,
+ false,
+ );
- return Err(diag.emit());
- }
+ return Err(diag.emit());
+ }
- // Check that all obligations are satisfied by the implementation's
- // version.
- let errors = ocx.select_all_or_error();
- if !errors.is_empty() {
- let reported = infcx.report_fulfillment_errors(&errors, None, false);
- return Err(reported);
- }
+ // Check that all obligations are satisfied by the implementation's
+ // version.
+ let errors = ocx.select_all_or_error();
+ if !errors.is_empty() {
+ let reported = infcx.err_ctxt().report_fulfillment_errors(&errors, None, false);
+ return Err(reported);
+ }
- // Finally, resolve all regions. This catches wily misuses of
- // lifetime parameters.
- let outlives_environment = OutlivesEnvironment::with_bounds(
- param_env,
- Some(infcx),
- infcx.implied_bounds_tys(param_env, impl_m_hir_id, wf_tys),
- );
- infcx.check_region_obligations_and_report_errors(
- impl_m.def_id.expect_local(),
- &outlives_environment,
- );
+ // Finally, resolve all regions. This catches wily misuses of
+ // lifetime parameters.
+ let outlives_environment = OutlivesEnvironment::with_bounds(
+ param_env,
+ Some(infcx),
+ infcx.implied_bounds_tys(param_env, impl_m_hir_id, wf_tys),
+ );
+ infcx.check_region_obligations_and_report_errors(
+ impl_m.def_id.expect_local(),
+ &outlives_environment,
+ );
- Ok(())
- })
+ Ok(())
}
pub fn collect_trait_impl_trait_tys<'tcx>(
let trait_to_placeholder_substs =
impl_to_placeholder_substs.rebase_onto(tcx, impl_m.container_id(tcx), trait_to_impl_substs);
- tcx.infer_ctxt().enter(|ref infcx| {
- let ocx = ObligationCtxt::new(infcx);
+ let infcx = &tcx.infer_ctxt().build();
+ let ocx = ObligationCtxt::new(infcx);
- let norm_cause = ObligationCause::misc(return_span, impl_m_hir_id);
- let impl_return_ty = ocx.normalize(
- norm_cause.clone(),
- param_env,
- infcx
- .replace_bound_vars_with_fresh_vars(
- return_span,
- infer::HigherRankedType,
- tcx.fn_sig(impl_m.def_id),
- )
- .output(),
- );
+ let norm_cause = ObligationCause::misc(return_span, impl_m_hir_id);
+ let impl_sig = ocx.normalize(
+ norm_cause.clone(),
+ param_env,
+ infcx.replace_bound_vars_with_fresh_vars(
+ return_span,
+ infer::HigherRankedType,
+ tcx.fn_sig(impl_m.def_id),
+ ),
+ );
+ let impl_return_ty = impl_sig.output();
- let mut collector =
- ImplTraitInTraitCollector::new(&ocx, return_span, param_env, impl_m_hir_id);
- let unnormalized_trait_return_ty = tcx
- .liberate_late_bound_regions(
- impl_m.def_id,
- tcx.bound_fn_sig(trait_m.def_id).subst(tcx, trait_to_placeholder_substs),
- )
- .output()
- .fold_with(&mut collector);
- let trait_return_ty =
- ocx.normalize(norm_cause.clone(), param_env, unnormalized_trait_return_ty);
+ let mut collector = ImplTraitInTraitCollector::new(&ocx, return_span, param_env, impl_m_hir_id);
+ let unnormalized_trait_sig = tcx
+ .liberate_late_bound_regions(
+ impl_m.def_id,
+ tcx.bound_fn_sig(trait_m.def_id).subst(tcx, trait_to_placeholder_substs),
+ )
+ .fold_with(&mut collector);
+ let trait_sig = ocx.normalize(norm_cause.clone(), param_env, unnormalized_trait_sig);
+ let trait_return_ty = trait_sig.output();
- let wf_tys = FxHashSet::from_iter([unnormalized_trait_return_ty, trait_return_ty]);
+ let wf_tys = FxHashSet::from_iter(
+ unnormalized_trait_sig.inputs_and_output.iter().chain(trait_sig.inputs_and_output.iter()),
+ );
- match infcx.at(&cause, param_env).eq(trait_return_ty, impl_return_ty) {
- Ok(infer::InferOk { value: (), obligations }) => {
- ocx.register_obligations(obligations);
- }
- Err(terr) => {
- let mut diag = struct_span_err!(
- tcx.sess,
- cause.span(),
- E0053,
- "method `{}` has an incompatible return type for trait",
- trait_m.name
- );
- let hir = tcx.hir();
- infcx.note_type_err(
- &mut diag,
- &cause,
- hir.get_if_local(impl_m.def_id)
- .and_then(|node| node.fn_decl())
- .map(|decl| (decl.output.span(), "return type in trait".to_owned())),
- Some(infer::ValuePairs::Terms(ExpectedFound {
- expected: trait_return_ty.into(),
- found: impl_return_ty.into(),
- })),
- terr,
- false,
- false,
- );
- return Err(diag.emit());
- }
+ match infcx.at(&cause, param_env).eq(trait_return_ty, impl_return_ty) {
+ Ok(infer::InferOk { value: (), obligations }) => {
+ ocx.register_obligations(obligations);
}
+ Err(terr) => {
+ let mut diag = struct_span_err!(
+ tcx.sess,
+ cause.span(),
+ E0053,
+ "method `{}` has an incompatible return type for trait",
+ trait_m.name
+ );
+ let hir = tcx.hir();
+ infcx.err_ctxt().note_type_err(
+ &mut diag,
+ &cause,
+ hir.get_if_local(impl_m.def_id)
+ .and_then(|node| node.fn_decl())
+ .map(|decl| (decl.output.span(), "return type in trait".to_owned())),
+ Some(infer::ValuePairs::Terms(ExpectedFound {
+ expected: trait_return_ty.into(),
+ found: impl_return_ty.into(),
+ })),
+ terr,
+ false,
+ false,
+ );
+ return Err(diag.emit());
+ }
+ }
- // Check that all obligations are satisfied by the implementation's
- // RPITs.
- let errors = ocx.select_all_or_error();
- if !errors.is_empty() {
- let reported = infcx.report_fulfillment_errors(&errors, None, false);
- return Err(reported);
+ // Unify the whole function signature. We need to do this to fully infer
+ // the lifetimes of the return type, but do this after unifying just the
+ // return types, since we want to avoid duplicating errors from
+ // `compare_predicate_entailment`.
+ match infcx
+ .at(&cause, param_env)
+ .eq(tcx.mk_fn_ptr(ty::Binder::dummy(trait_sig)), tcx.mk_fn_ptr(ty::Binder::dummy(impl_sig)))
+ {
+ Ok(infer::InferOk { value: (), obligations }) => {
+ ocx.register_obligations(obligations);
}
+ Err(terr) => {
+ let guar = tcx.sess.delay_span_bug(
+ return_span,
+ format!("could not unify `{trait_sig}` and `{impl_sig}`: {terr:?}"),
+ );
+ return Err(guar);
+ }
+ }
- // Finally, resolve all regions. This catches wily misuses of
- // lifetime parameters.
- let outlives_environment = OutlivesEnvironment::with_bounds(
- param_env,
- Some(infcx),
- infcx.implied_bounds_tys(param_env, impl_m_hir_id, wf_tys),
- );
- infcx.check_region_obligations_and_report_errors(
- impl_m.def_id.expect_local(),
- &outlives_environment,
- );
+ // Check that all obligations are satisfied by the implementation's
+ // RPITs.
+ let errors = ocx.select_all_or_error();
+ if !errors.is_empty() {
+ let reported = infcx.err_ctxt().report_fulfillment_errors(&errors, None, false);
+ return Err(reported);
+ }
- let mut collected_tys = FxHashMap::default();
- for (def_id, (ty, substs)) in collector.types {
- match infcx.fully_resolve(ty) {
- Ok(ty) => {
- // `ty` contains free regions that we created earlier while liberating the
- // trait fn signature. However, projection normalization expects `ty` to
- // contains `def_id`'s early-bound regions.
- let id_substs = InternalSubsts::identity_for_item(tcx, def_id);
- debug!(?id_substs, ?substs);
- let map: FxHashMap<ty::GenericArg<'tcx>, ty::GenericArg<'tcx>> = substs
- .iter()
- .enumerate()
- .map(|(index, arg)| (arg, id_substs[index]))
- .collect();
- debug!(?map);
-
- let ty = tcx.fold_regions(ty, |region, _| {
- if let ty::ReFree(_) = region.kind() {
- map[®ion.into()].expect_region()
- } else {
- region
- }
- });
- debug!(%ty);
- collected_tys.insert(def_id, ty);
- }
- Err(err) => {
- tcx.sess.delay_span_bug(
- return_span,
- format!("could not fully resolve: {ty} => {err:?}"),
- );
- collected_tys.insert(def_id, tcx.ty_error());
- }
+ // Finally, resolve all regions. This catches wily misuses of
+ // lifetime parameters.
+ let outlives_environment = OutlivesEnvironment::with_bounds(
+ param_env,
+ Some(infcx),
+ infcx.implied_bounds_tys(param_env, impl_m_hir_id, wf_tys),
+ );
+ infcx.check_region_obligations_and_report_errors(
+ impl_m.def_id.expect_local(),
+ &outlives_environment,
+ );
+
+ let mut collected_tys = FxHashMap::default();
+ for (def_id, (ty, substs)) in collector.types {
+ match infcx.fully_resolve(ty) {
+ Ok(ty) => {
+ // `ty` contains free regions that we created earlier while liberating the
+ // trait fn signature. However, projection normalization expects `ty` to
+ // contains `def_id`'s early-bound regions.
+ let id_substs = InternalSubsts::identity_for_item(tcx, def_id);
+ debug!(?id_substs, ?substs);
+ let map: FxHashMap<ty::GenericArg<'tcx>, ty::GenericArg<'tcx>> =
+ std::iter::zip(substs, id_substs).collect();
+ debug!(?map);
+
+ // NOTE(compiler-errors): RPITITs, like all other RPITs, have early-bound
+ // region substs that are synthesized during AST lowering. These are substs
+ // that are appended to the parent substs (trait and trait method). However,
+ // we're trying to infer the unsubstituted type value of the RPITIT inside
+ // the *impl*, so we can later use the impl's method substs to normalize
+ // an RPITIT to a concrete type (`confirm_impl_trait_in_trait_candidate`).
+ //
+ // Due to the design of RPITITs, during AST lowering, we have no idea that
+ // an impl method corresponds to a trait method with RPITITs in it. Therefore,
+ // we don't have a list of early-bound region substs for the RPITIT in the impl.
+ // Since early region parameters are index-based, we can't just rebase these
+ // (trait method) early-bound region substs onto the impl, and there's no
+ // guarantee that the indices from the trait substs and impl substs line up.
+ // So to fix this, we subtract the number of trait substs and add the number of
+ // impl substs to *renumber* these early-bound regions to their corresponding
+ // indices in the impl's substitutions list.
+ //
+ // Also, we only need to account for a difference in trait and impl substs,
+ // since we previously enforce that the trait method and impl method have the
+ // same generics.
+ let num_trait_substs = trait_to_impl_substs.len();
+ let num_impl_substs = tcx.generics_of(impl_m.container_id(tcx)).params.len();
+ let ty = tcx.fold_regions(ty, |region, _| {
+ let ty::ReFree(_) = region.kind() else { return region; };
+ let ty::ReEarlyBound(e) = map[®ion.into()].expect_region().kind()
+ else { bug!("expected ReFree to map to ReEarlyBound"); };
+ tcx.mk_region(ty::ReEarlyBound(ty::EarlyBoundRegion {
+ def_id: e.def_id,
+ name: e.name,
+ index: (e.index as usize - num_trait_substs + num_impl_substs) as u32,
+ }))
+ });
+ debug!(%ty);
+ collected_tys.insert(def_id, ty);
+ }
+ Err(err) => {
+ tcx.sess.delay_span_bug(
+ return_span,
+ format!("could not fully resolve: {ty} => {err:?}"),
+ );
+ collected_tys.insert(def_id, tcx.ty_error());
}
}
+ }
- Ok(&*tcx.arena.alloc(collected_tys))
- })
+ Ok(&*tcx.arena.alloc(collected_tys))
}
struct ImplTraitInTraitCollector<'a, 'tcx> {
}
#[instrument(level = "debug", skip(infcx))]
-fn extract_spans_for_error_reporting<'a, 'tcx>(
- infcx: &infer::InferCtxt<'a, 'tcx>,
+fn extract_spans_for_error_reporting<'tcx>(
+ infcx: &infer::InferCtxt<'tcx>,
terr: TypeError<'_>,
cause: &ObligationCause<'tcx>,
impl_m: &ty::AssocItem,
let self_arg_ty = tcx.fn_sig(method.def_id).input(0);
let param_env = ty::ParamEnv::reveal_all();
- tcx.infer_ctxt().enter(|infcx| {
- let self_arg_ty = tcx.liberate_late_bound_regions(method.def_id, self_arg_ty);
- let can_eq_self = |ty| infcx.can_eq(param_env, untransformed_self_ty, ty).is_ok();
- match ExplicitSelf::determine(self_arg_ty, can_eq_self) {
- ExplicitSelf::ByValue => "self".to_owned(),
- ExplicitSelf::ByReference(_, hir::Mutability::Not) => "&self".to_owned(),
- ExplicitSelf::ByReference(_, hir::Mutability::Mut) => "&mut self".to_owned(),
- _ => format!("self: {self_arg_ty}"),
- }
- })
+ let infcx = tcx.infer_ctxt().build();
+ let self_arg_ty = tcx.liberate_late_bound_regions(method.def_id, self_arg_ty);
+ let can_eq_self = |ty| infcx.can_eq(param_env, untransformed_self_ty, ty).is_ok();
+ match ExplicitSelf::determine(self_arg_ty, can_eq_self) {
+ ExplicitSelf::ByValue => "self".to_owned(),
+ ExplicitSelf::ByReference(_, hir::Mutability::Not) => "&self".to_owned(),
+ ExplicitSelf::ByReference(_, hir::Mutability::Mut) => "&mut self".to_owned(),
+ _ => format!("self: {self_arg_ty}"),
+ }
};
match (trait_m.fn_has_self_parameter, impl_m.fn_has_self_parameter) {
let impl_c_span = tcx.def_span(impl_const_item_def.to_def_id());
- tcx.infer_ctxt().enter(|infcx| {
- let param_env = tcx.param_env(impl_const_item_def.to_def_id());
- let ocx = ObligationCtxt::new(&infcx);
-
- // The below is for the most part highly similar to the procedure
- // for methods above. It is simpler in many respects, especially
- // because we shouldn't really have to deal with lifetimes or
- // predicates. In fact some of this should probably be put into
- // shared functions because of DRY violations...
- let trait_to_impl_substs = impl_trait_ref.substs;
-
- // Create a parameter environment that represents the implementation's
- // method.
- let impl_c_hir_id = tcx.hir().local_def_id_to_hir_id(impl_const_item_def);
-
- // Compute placeholder form of impl and trait const tys.
- let impl_ty = tcx.type_of(impl_const_item_def.to_def_id());
- let trait_ty = tcx.bound_type_of(trait_const_item_def).subst(tcx, trait_to_impl_substs);
- let mut cause = ObligationCause::new(
- impl_c_span,
- impl_c_hir_id,
- ObligationCauseCode::CompareImplItemObligation {
- impl_item_def_id: impl_const_item_def,
- trait_item_def_id: trait_const_item_def,
- kind: impl_const_item.kind,
- },
- );
+ let infcx = tcx.infer_ctxt().build();
+ let param_env = tcx.param_env(impl_const_item_def.to_def_id());
+ let ocx = ObligationCtxt::new(&infcx);
- // There is no "body" here, so just pass dummy id.
- let impl_ty = ocx.normalize(cause.clone(), param_env, impl_ty);
+ // The below is for the most part highly similar to the procedure
+ // for methods above. It is simpler in many respects, especially
+ // because we shouldn't really have to deal with lifetimes or
+ // predicates. In fact some of this should probably be put into
+ // shared functions because of DRY violations...
+ let trait_to_impl_substs = impl_trait_ref.substs;
- debug!("compare_const_impl: impl_ty={:?}", impl_ty);
+ // Create a parameter environment that represents the implementation's
+ // method.
+ let impl_c_hir_id = tcx.hir().local_def_id_to_hir_id(impl_const_item_def);
- let trait_ty = ocx.normalize(cause.clone(), param_env, trait_ty);
+ // Compute placeholder form of impl and trait const tys.
+ let impl_ty = tcx.type_of(impl_const_item_def.to_def_id());
+ let trait_ty = tcx.bound_type_of(trait_const_item_def).subst(tcx, trait_to_impl_substs);
+ let mut cause = ObligationCause::new(
+ impl_c_span,
+ impl_c_hir_id,
+ ObligationCauseCode::CompareImplItemObligation {
+ impl_item_def_id: impl_const_item_def,
+ trait_item_def_id: trait_const_item_def,
+ kind: impl_const_item.kind,
+ },
+ );
- debug!("compare_const_impl: trait_ty={:?}", trait_ty);
+ // There is no "body" here, so just pass dummy id.
+ let impl_ty = ocx.normalize(cause.clone(), param_env, impl_ty);
- let err = infcx
- .at(&cause, param_env)
- .sup(trait_ty, impl_ty)
- .map(|ok| ocx.register_infer_ok_obligations(ok));
+ debug!("compare_const_impl: impl_ty={:?}", impl_ty);
- if let Err(terr) = err {
- debug!(
- "checking associated const for compatibility: impl ty {:?}, trait ty {:?}",
- impl_ty, trait_ty
- );
+ let trait_ty = ocx.normalize(cause.clone(), param_env, trait_ty);
- // Locate the Span containing just the type of the offending impl
- match tcx.hir().expect_impl_item(impl_const_item_def).kind {
- ImplItemKind::Const(ref ty, _) => cause.span = ty.span,
- _ => bug!("{:?} is not a impl const", impl_const_item),
- }
+ debug!("compare_const_impl: trait_ty={:?}", trait_ty);
- let mut diag = struct_span_err!(
- tcx.sess,
- cause.span,
- E0326,
- "implemented const `{}` has an incompatible type for trait",
- trait_const_item.name
- );
+ let err = infcx
+ .at(&cause, param_env)
+ .sup(trait_ty, impl_ty)
+ .map(|ok| ocx.register_infer_ok_obligations(ok));
- let trait_c_span = trait_const_item_def.as_local().map(|trait_c_def_id| {
- // Add a label to the Span containing just the type of the const
- match tcx.hir().expect_trait_item(trait_c_def_id).kind {
- TraitItemKind::Const(ref ty, _) => ty.span,
- _ => bug!("{:?} is not a trait const", trait_const_item),
- }
- });
-
- infcx.note_type_err(
- &mut diag,
- &cause,
- trait_c_span.map(|span| (span, "type in trait".to_owned())),
- Some(infer::ValuePairs::Terms(ExpectedFound {
- expected: trait_ty.into(),
- found: impl_ty.into(),
- })),
- terr,
- false,
- false,
- );
- return Err(diag.emit());
- };
+ if let Err(terr) = err {
+ debug!(
+ "checking associated const for compatibility: impl ty {:?}, trait ty {:?}",
+ impl_ty, trait_ty
+ );
- // Check that all obligations are satisfied by the implementation's
- // version.
- let errors = ocx.select_all_or_error();
- if !errors.is_empty() {
- return Err(infcx.report_fulfillment_errors(&errors, None, false));
+ // Locate the Span containing just the type of the offending impl
+ match tcx.hir().expect_impl_item(impl_const_item_def).kind {
+ ImplItemKind::Const(ref ty, _) => cause.span = ty.span,
+ _ => bug!("{:?} is not a impl const", impl_const_item),
}
- // FIXME return `ErrorReported` if region obligations error?
- let outlives_environment = OutlivesEnvironment::new(param_env);
- infcx
- .check_region_obligations_and_report_errors(impl_const_item_def, &outlives_environment);
- Ok(())
- })
+ let mut diag = struct_span_err!(
+ tcx.sess,
+ cause.span,
+ E0326,
+ "implemented const `{}` has an incompatible type for trait",
+ trait_const_item.name
+ );
+
+ let trait_c_span = trait_const_item_def.as_local().map(|trait_c_def_id| {
+ // Add a label to the Span containing just the type of the const
+ match tcx.hir().expect_trait_item(trait_c_def_id).kind {
+ TraitItemKind::Const(ref ty, _) => ty.span,
+ _ => bug!("{:?} is not a trait const", trait_const_item),
+ }
+ });
+
+ infcx.err_ctxt().note_type_err(
+ &mut diag,
+ &cause,
+ trait_c_span.map(|span| (span, "type in trait".to_owned())),
+ Some(infer::ValuePairs::Terms(ExpectedFound {
+ expected: trait_ty.into(),
+ found: impl_ty.into(),
+ })),
+ terr,
+ false,
+ false,
+ );
+ return Err(diag.emit());
+ };
+
+ // Check that all obligations are satisfied by the implementation's
+ // version.
+ let errors = ocx.select_all_or_error();
+ if !errors.is_empty() {
+ return Err(infcx.err_ctxt().report_fulfillment_errors(&errors, None, false));
+ }
+
+ // FIXME return `ErrorReported` if region obligations error?
+ let outlives_environment = OutlivesEnvironment::new(param_env);
+ infcx.check_region_obligations_and_report_errors(impl_const_item_def, &outlives_environment);
+ Ok(())
}
pub(crate) fn compare_ty_impl<'tcx>(
hir::Constness::NotConst,
);
let param_env = traits::normalize_param_env_or_error(tcx, param_env, normalize_cause);
- tcx.infer_ctxt().enter(|infcx| {
- let ocx = ObligationCtxt::new(&infcx);
+ let infcx = tcx.infer_ctxt().build();
+ let ocx = ObligationCtxt::new(&infcx);
- debug!("compare_type_predicate_entailment: caller_bounds={:?}", param_env.caller_bounds());
+ debug!("compare_type_predicate_entailment: caller_bounds={:?}", param_env.caller_bounds());
- let mut selcx = traits::SelectionContext::new(&infcx);
+ let mut selcx = traits::SelectionContext::new(&infcx);
- assert_eq!(impl_ty_own_bounds.predicates.len(), impl_ty_own_bounds.spans.len());
- for (span, predicate) in
- std::iter::zip(impl_ty_own_bounds.spans, impl_ty_own_bounds.predicates)
- {
- let cause = ObligationCause::misc(span, impl_ty_hir_id);
- let traits::Normalized { value: predicate, obligations } =
- traits::normalize(&mut selcx, param_env, cause, predicate);
-
- let cause = ObligationCause::new(
- span,
- impl_ty_hir_id,
- ObligationCauseCode::CompareImplItemObligation {
- impl_item_def_id: impl_ty.def_id.expect_local(),
- trait_item_def_id: trait_ty.def_id,
- kind: impl_ty.kind,
- },
- );
- ocx.register_obligations(obligations);
- ocx.register_obligation(traits::Obligation::new(cause, param_env, predicate));
- }
-
- // Check that all obligations are satisfied by the implementation's
- // version.
- let errors = ocx.select_all_or_error();
- if !errors.is_empty() {
- let reported = infcx.report_fulfillment_errors(&errors, None, false);
- return Err(reported);
- }
+ assert_eq!(impl_ty_own_bounds.predicates.len(), impl_ty_own_bounds.spans.len());
+ for (span, predicate) in std::iter::zip(impl_ty_own_bounds.spans, impl_ty_own_bounds.predicates)
+ {
+ let cause = ObligationCause::misc(span, impl_ty_hir_id);
+ let traits::Normalized { value: predicate, obligations } =
+ traits::normalize(&mut selcx, param_env, cause, predicate);
- // Finally, resolve all regions. This catches wily misuses of
- // lifetime parameters.
- let outlives_environment = OutlivesEnvironment::new(param_env);
- infcx.check_region_obligations_and_report_errors(
- impl_ty.def_id.expect_local(),
- &outlives_environment,
+ let cause = ObligationCause::new(
+ span,
+ impl_ty_hir_id,
+ ObligationCauseCode::CompareImplItemObligation {
+ impl_item_def_id: impl_ty.def_id.expect_local(),
+ trait_item_def_id: trait_ty.def_id,
+ kind: impl_ty.kind,
+ },
);
+ ocx.register_obligations(obligations);
+ ocx.register_obligation(traits::Obligation::new(cause, param_env, predicate));
+ }
+
+ // Check that all obligations are satisfied by the implementation's
+ // version.
+ let errors = ocx.select_all_or_error();
+ if !errors.is_empty() {
+ let reported = infcx.err_ctxt().report_fulfillment_errors(&errors, None, false);
+ return Err(reported);
+ }
- Ok(())
- })
+ // Finally, resolve all regions. This catches wily misuses of
+ // lifetime parameters.
+ let outlives_environment = OutlivesEnvironment::new(param_env);
+ infcx.check_region_obligations_and_report_errors(
+ impl_ty.def_id.expect_local(),
+ &outlives_environment,
+ );
+
+ Ok(())
}
/// Validate that `ProjectionCandidate`s created for this associated type will
let impl_ty_substs = InternalSubsts::identity_for_item(tcx, impl_ty.def_id);
let rebased_substs = impl_ty_substs.rebase_onto(tcx, container_id, impl_trait_ref.substs);
- tcx.infer_ctxt().enter(move |infcx| {
- let ocx = ObligationCtxt::new(&infcx);
+ let infcx = tcx.infer_ctxt().build();
+ let ocx = ObligationCtxt::new(&infcx);
- let assumed_wf_types =
- ocx.assumed_wf_types(param_env, impl_ty_span, impl_ty.def_id.expect_local());
+ let assumed_wf_types =
+ ocx.assumed_wf_types(param_env, impl_ty_span, impl_ty.def_id.expect_local());
- let mut selcx = traits::SelectionContext::new(&infcx);
- let normalize_cause = ObligationCause::new(
- impl_ty_span,
- impl_ty_hir_id,
- ObligationCauseCode::CheckAssociatedTypeBounds {
- impl_item_def_id: impl_ty.def_id.expect_local(),
- trait_item_def_id: trait_ty.def_id,
- },
- );
- let mk_cause = |span: Span| {
- let code = if span.is_dummy() {
- traits::ItemObligation(trait_ty.def_id)
- } else {
- traits::BindingObligation(trait_ty.def_id, span)
- };
- ObligationCause::new(impl_ty_span, impl_ty_hir_id, code)
+ let mut selcx = traits::SelectionContext::new(&infcx);
+ let normalize_cause = ObligationCause::new(
+ impl_ty_span,
+ impl_ty_hir_id,
+ ObligationCauseCode::CheckAssociatedTypeBounds {
+ impl_item_def_id: impl_ty.def_id.expect_local(),
+ trait_item_def_id: trait_ty.def_id,
+ },
+ );
+ let mk_cause = |span: Span| {
+ let code = if span.is_dummy() {
+ traits::ItemObligation(trait_ty.def_id)
+ } else {
+ traits::BindingObligation(trait_ty.def_id, span)
};
+ ObligationCause::new(impl_ty_span, impl_ty_hir_id, code)
+ };
- let obligations = tcx
- .bound_explicit_item_bounds(trait_ty.def_id)
- .transpose_iter()
- .map(|e| e.map_bound(|e| *e).transpose_tuple2())
- .map(|(bound, span)| {
- debug!(?bound);
- // this is where opaque type is found
- let concrete_ty_bound = bound.subst(tcx, rebased_substs);
- debug!("check_type_bounds: concrete_ty_bound = {:?}", concrete_ty_bound);
-
- traits::Obligation::new(mk_cause(span.0), param_env, concrete_ty_bound)
- })
- .collect();
- debug!("check_type_bounds: item_bounds={:?}", obligations);
-
- for mut obligation in util::elaborate_obligations(tcx, obligations) {
- let traits::Normalized { value: normalized_predicate, obligations } = traits::normalize(
- &mut selcx,
- normalize_param_env,
- normalize_cause.clone(),
- obligation.predicate,
- );
- debug!("compare_projection_bounds: normalized predicate = {:?}", normalized_predicate);
- obligation.predicate = normalized_predicate;
+ let obligations = tcx
+ .bound_explicit_item_bounds(trait_ty.def_id)
+ .transpose_iter()
+ .map(|e| e.map_bound(|e| *e).transpose_tuple2())
+ .map(|(bound, span)| {
+ debug!(?bound);
+ // this is where opaque type is found
+ let concrete_ty_bound = bound.subst(tcx, rebased_substs);
+ debug!("check_type_bounds: concrete_ty_bound = {:?}", concrete_ty_bound);
+
+ traits::Obligation::new(mk_cause(span.0), param_env, concrete_ty_bound)
+ })
+ .collect();
+ debug!("check_type_bounds: item_bounds={:?}", obligations);
+
+ for mut obligation in util::elaborate_obligations(tcx, obligations) {
+ let traits::Normalized { value: normalized_predicate, obligations } = traits::normalize(
+ &mut selcx,
+ normalize_param_env,
+ normalize_cause.clone(),
+ obligation.predicate,
+ );
+ debug!("compare_projection_bounds: normalized predicate = {:?}", normalized_predicate);
+ obligation.predicate = normalized_predicate;
- ocx.register_obligations(obligations);
- ocx.register_obligation(obligation);
- }
- // Check that all obligations are satisfied by the implementation's
- // version.
- let errors = ocx.select_all_or_error();
- if !errors.is_empty() {
- let reported = infcx.report_fulfillment_errors(&errors, None, false);
- return Err(reported);
- }
+ ocx.register_obligations(obligations);
+ ocx.register_obligation(obligation);
+ }
+ // Check that all obligations are satisfied by the implementation's
+ // version.
+ let errors = ocx.select_all_or_error();
+ if !errors.is_empty() {
+ let reported = infcx.err_ctxt().report_fulfillment_errors(&errors, None, false);
+ return Err(reported);
+ }
- // Finally, resolve all regions. This catches wily misuses of
- // lifetime parameters.
- let implied_bounds = infcx.implied_bounds_tys(param_env, impl_ty_hir_id, assumed_wf_types);
- let outlives_environment =
- OutlivesEnvironment::with_bounds(param_env, Some(&infcx), implied_bounds);
+ // Finally, resolve all regions. This catches wily misuses of
+ // lifetime parameters.
+ let implied_bounds = infcx.implied_bounds_tys(param_env, impl_ty_hir_id, assumed_wf_types);
+ let outlives_environment =
+ OutlivesEnvironment::with_bounds(param_env, Some(&infcx), implied_bounds);
- infcx.check_region_obligations_and_report_errors(
- impl_ty.def_id.expect_local(),
- &outlives_environment,
- );
+ infcx.check_region_obligations_and_report_errors(
+ impl_ty.def_id.expect_local(),
+ &outlives_environment,
+ );
- let constraints = infcx.inner.borrow_mut().opaque_type_storage.take_opaque_types();
- for (key, value) in constraints {
- infcx
- .report_mismatched_types(
- &ObligationCause::misc(
- value.hidden_type.span,
- tcx.hir().local_def_id_to_hir_id(impl_ty.def_id.expect_local()),
- ),
- tcx.mk_opaque(key.def_id.to_def_id(), key.substs),
- value.hidden_type.ty,
- TypeError::Mismatch,
- )
- .emit();
- }
+ let constraints = infcx.inner.borrow_mut().opaque_type_storage.take_opaque_types();
+ for (key, value) in constraints {
+ infcx
+ .err_ctxt()
+ .report_mismatched_types(
+ &ObligationCause::misc(
+ value.hidden_type.span,
+ tcx.hir().local_def_id_to_hir_id(impl_ty.def_id.expect_local()),
+ ),
+ tcx.mk_opaque(key.def_id.to_def_id(), key.substs),
+ value.hidden_type.ty,
+ TypeError::Mismatch,
+ )
+ .emit();
+ }
- Ok(())
- })
+ Ok(())
}
fn assoc_item_kind_str(impl_item: &ty::AssocItem) -> &'static str {
projects / rust.git / blobdiff