use super::{
- DerivedObligationCause, EvaluationResult, ImplDerivedObligationCause, Obligation,
- ObligationCause, ObligationCauseCode, PredicateObligation, SelectionContext,
+ EvaluationResult, Obligation, ObligationCause, ObligationCauseCode, PredicateObligation,
+ SelectionContext,
};
use crate::autoderef::Autoderef;
let span = obligation.cause.span;
let mut real_trait_pred = trait_pred;
let mut code = obligation.cause.code();
- loop {
- match &code {
- ObligationCauseCode::FunctionArgumentObligation { parent_code, .. } => {
- code = &parent_code;
- }
- ObligationCauseCode::ImplDerivedObligation(box ImplDerivedObligationCause {
- derived: DerivedObligationCause { parent_code, parent_trait_pred },
- ..
- })
- | ObligationCauseCode::BuiltinDerivedObligation(DerivedObligationCause {
- parent_code,
- parent_trait_pred,
- })
- | ObligationCauseCode::DerivedObligation(DerivedObligationCause {
- parent_code,
- parent_trait_pred,
- }) => {
- code = &parent_code;
- real_trait_pred = *parent_trait_pred;
- }
- _ => break,
- };
- let Some(real_ty) = real_trait_pred.self_ty().no_bound_vars() else {
- continue;
- };
+ while let Some((parent_code, parent_trait_pred)) = code.parent() {
+ code = parent_code;
+ if let Some(parent_trait_pred) = parent_trait_pred {
+ real_trait_pred = parent_trait_pred;
+ }
+
+ // Skipping binder here, remapping below
+ let real_ty = real_trait_pred.self_ty().skip_binder();
if let ty::Ref(region, base_ty, mutbl) = *real_ty.kind() {
let mut autoderef = Autoderef::new(self, param_env, body_id, span, base_ty, span);
if let Some(steps) = autoderef.find_map(|(ty, steps)| {
// Re-add the `&`
let ty = self.tcx.mk_ref(region, TypeAndMut { ty, mutbl });
- let obligation =
- self.mk_trait_obligation_with_new_self_ty(param_env, real_trait_pred, ty);
+
+ // Remapping bound vars here
+ let real_trait_pred_and_ty =
+ real_trait_pred.map_bound(|inner_trait_pred| (inner_trait_pred, ty));
+ let obligation = self
+ .mk_trait_obligation_with_new_self_ty(param_env, real_trait_pred_and_ty);
Some(steps).filter(|_| self.predicate_may_hold(&obligation))
}) {
if steps > 0 {
}
} else if real_trait_pred != trait_pred {
// This branch addresses #87437.
+
+ // Remapping bound vars here
+ let real_trait_pred_and_base_ty =
+ real_trait_pred.map_bound(|inner_trait_pred| (inner_trait_pred, base_ty));
let obligation = self.mk_trait_obligation_with_new_self_ty(
param_env,
- real_trait_pred,
- base_ty,
+ real_trait_pred_and_base_ty,
);
if self.predicate_may_hold(&obligation) {
err.span_suggestion_verbose(
err: &mut Diagnostic,
trait_pred: ty::PolyTraitPredicate<'tcx>,
) -> bool {
- let Some(self_ty) = trait_pred.self_ty().no_bound_vars() else {
- return false;
- };
+ // Skipping binder here, remapping below
+ let self_ty = trait_pred.self_ty().skip_binder();
let (def_id, output_ty, callable) = match *self_ty.kind() {
ty::Closure(def_id, substs) => (def_id, substs.as_closure().sig().output(), "closure"),
};
let msg = format!("use parentheses to call the {}", callable);
- // `mk_trait_obligation_with_new_self_ty` only works for types with no escaping bound
- // variables, so bail out if we have any.
- let Some(output_ty) = output_ty.no_bound_vars() else {
- return false;
- };
+ // "We should really create a single list of bound vars from the combined vars
+ // from the predicate and function, but instead we just liberate the function bound vars"
+ let output_ty = self.tcx.liberate_late_bound_regions(def_id, output_ty);
+
+ // Remapping bound vars here
+ let trait_pred_and_self = trait_pred.map_bound(|trait_pred| (trait_pred, output_ty));
let new_obligation =
- self.mk_trait_obligation_with_new_self_ty(obligation.param_env, trait_pred, output_ty);
+ self.mk_trait_obligation_with_new_self_ty(obligation.param_env, trait_pred_and_self);
match self.evaluate_obligation(&new_obligation) {
Ok(
let param_env = obligation.param_env;
// Try to apply the original trait binding obligation by borrowing.
- let mut try_borrowing = |old_pred: ty::PolyTraitPredicate<'tcx>,
- blacklist: &[DefId]|
- -> bool {
- if blacklist.contains(&old_pred.def_id()) {
- return false;
- }
-
- // This is a quick fix to resolve an ICE (#96223).
- // This change should probably be deeper.
- // As suggested by @jackh726, `mk_trait_obligation_with_new_self_ty` could take a `Binder<(TraitRef, Ty)>
- // instead of `Binder<Ty>` leading to some changes to its call places.
- let Some(orig_ty) = old_pred.self_ty().no_bound_vars() else {
- return false;
- };
- let mk_result = |new_ty| {
- let obligation =
- self.mk_trait_obligation_with_new_self_ty(param_env, old_pred, new_ty);
- self.predicate_must_hold_modulo_regions(&obligation)
- };
- let imm_result = mk_result(self.tcx.mk_imm_ref(self.tcx.lifetimes.re_static, orig_ty));
- let mut_result = mk_result(self.tcx.mk_mut_ref(self.tcx.lifetimes.re_static, orig_ty));
-
- if imm_result || mut_result {
- if let Ok(snippet) = self.tcx.sess.source_map().span_to_snippet(span) {
- // We have a very specific type of error, where just borrowing this argument
- // might solve the problem. In cases like this, the important part is the
- // original type obligation, not the last one that failed, which is arbitrary.
- // Because of this, we modify the error to refer to the original obligation and
- // return early in the caller.
-
- let msg = format!(
- "the trait bound `{}: {}` is not satisfied",
- orig_ty,
- old_pred.print_modifiers_and_trait_path(),
- );
- if has_custom_message {
- err.note(&msg);
- } else {
- err.message =
- vec![(rustc_errors::DiagnosticMessage::Str(msg), Style::NoStyle)];
- }
- if snippet.starts_with('&') {
- // This is already a literal borrow and the obligation is failing
- // somewhere else in the obligation chain. Do not suggest non-sense.
- return false;
- }
- err.span_label(
- span,
- &format!(
- "expected an implementor of trait `{}`",
- old_pred.print_modifiers_and_trait_path(),
- ),
- );
+ let mut try_borrowing =
+ |old_pred: ty::PolyTraitPredicate<'tcx>, blacklist: &[DefId]| -> bool {
+ if blacklist.contains(&old_pred.def_id()) {
+ return false;
+ }
+ // We map bounds to `&T` and `&mut T`
+ let trait_pred_and_imm_ref = old_pred.map_bound(|trait_pred| {
+ (
+ trait_pred,
+ self.tcx.mk_imm_ref(self.tcx.lifetimes.re_static, trait_pred.self_ty()),
+ )
+ });
+ let trait_pred_and_mut_ref = old_pred.map_bound(|trait_pred| {
+ (
+ trait_pred,
+ self.tcx.mk_mut_ref(self.tcx.lifetimes.re_static, trait_pred.self_ty()),
+ )
+ });
- // This if is to prevent a special edge-case
- if matches!(
- span.ctxt().outer_expn_data().kind,
- ExpnKind::Root | ExpnKind::Desugaring(DesugaringKind::ForLoop)
- ) {
- // We don't want a borrowing suggestion on the fields in structs,
- // ```
- // struct Foo {
- // the_foos: Vec<Foo>
- // }
- // ```
-
- if imm_result && mut_result {
- err.span_suggestions(
- span.shrink_to_lo(),
- "consider borrowing here",
- ["&".to_string(), "&mut ".to_string()].into_iter(),
- Applicability::MaybeIncorrect,
- );
+ let mk_result = |trait_pred_and_new_ty| {
+ let obligation =
+ self.mk_trait_obligation_with_new_self_ty(param_env, trait_pred_and_new_ty);
+ self.predicate_must_hold_modulo_regions(&obligation)
+ };
+ let imm_result = mk_result(trait_pred_and_imm_ref);
+ let mut_result = mk_result(trait_pred_and_mut_ref);
+
+ if imm_result || mut_result {
+ if let Ok(snippet) = self.tcx.sess.source_map().span_to_snippet(span) {
+ // We have a very specific type of error, where just borrowing this argument
+ // might solve the problem. In cases like this, the important part is the
+ // original type obligation, not the last one that failed, which is arbitrary.
+ // Because of this, we modify the error to refer to the original obligation and
+ // return early in the caller.
+
+ let msg = format!("the trait bound `{}` is not satisfied", old_pred);
+ if has_custom_message {
+ err.note(&msg);
} else {
- err.span_suggestion_verbose(
- span.shrink_to_lo(),
- &format!(
- "consider{} borrowing here",
- if mut_result { " mutably" } else { "" }
- ),
- format!("&{}", if mut_result { "mut " } else { "" }),
- Applicability::MaybeIncorrect,
- );
+ err.message =
+ vec![(rustc_errors::DiagnosticMessage::Str(msg), Style::NoStyle)];
+ }
+ if snippet.starts_with('&') {
+ // This is already a literal borrow and the obligation is failing
+ // somewhere else in the obligation chain. Do not suggest non-sense.
+ return false;
}
+ err.span_label(
+ span,
+ &format!(
+ "expected an implementor of trait `{}`",
+ old_pred.print_modifiers_and_trait_path(),
+ ),
+ );
+
+ // This if is to prevent a special edge-case
+ if matches!(
+ span.ctxt().outer_expn_data().kind,
+ ExpnKind::Root | ExpnKind::Desugaring(DesugaringKind::ForLoop)
+ ) {
+ // We don't want a borrowing suggestion on the fields in structs,
+ // ```
+ // struct Foo {
+ // the_foos: Vec<Foo>
+ // }
+ // ```
+
+ if imm_result && mut_result {
+ err.span_suggestions(
+ span.shrink_to_lo(),
+ "consider borrowing here",
+ ["&".to_string(), "&mut ".to_string()].into_iter(),
+ Applicability::MaybeIncorrect,
+ );
+ } else {
+ err.span_suggestion_verbose(
+ span.shrink_to_lo(),
+ &format!(
+ "consider{} borrowing here",
+ if mut_result { " mutably" } else { "" }
+ ),
+ format!("&{}", if mut_result { "mut " } else { "" }),
+ Applicability::MaybeIncorrect,
+ );
+ }
+ }
+ return true;
}
- return true;
}
- }
- return false;
- };
+ return false;
+ };
if let ObligationCauseCode::ImplDerivedObligation(cause) = &*code {
try_borrowing(cause.derived.parent_trait_pred, &[])
return false;
}
- let Some(mut suggested_ty) = trait_pred.self_ty().no_bound_vars() else {
- return false;
- };
+ // Skipping binder here, remapping below
+ let mut suggested_ty = trait_pred.self_ty().skip_binder();
for refs_remaining in 0..refs_number {
let ty::Ref(_, inner_ty, _) = suggested_ty.kind() else {
};
suggested_ty = *inner_ty;
+ // Remapping bound vars here
+ let trait_pred_and_suggested_ty =
+ trait_pred.map_bound(|trait_pred| (trait_pred, suggested_ty));
+
let new_obligation = self.mk_trait_obligation_with_new_self_ty(
obligation.param_env,
- trait_pred,
- suggested_ty,
+ trait_pred_and_suggested_ty,
);
if self.predicate_may_hold(&new_obligation) {
return;
}
+ // Skipping binder here, remapping below
if let ty::Ref(region, t_type, mutability) = *trait_pred.skip_binder().self_ty().kind()
{
- if region.is_late_bound() || t_type.has_escaping_bound_vars() {
- // Avoid debug assertion in `mk_obligation_for_def_id`.
- //
- // If the self type has escaping bound vars then it's not
- // going to be the type of an expression, so the suggestion
- // probably won't apply anyway.
- return;
- }
-
let suggested_ty = match mutability {
hir::Mutability::Mut => self.tcx.mk_imm_ref(region, t_type),
hir::Mutability::Not => self.tcx.mk_mut_ref(region, t_type),
};
+ // Remapping bound vars here
+ let trait_pred_and_suggested_ty =
+ trait_pred.map_bound(|trait_pred| (trait_pred, suggested_ty));
+
let new_obligation = self.mk_trait_obligation_with_new_self_ty(
obligation.param_env,
- trait_pred,
- suggested_ty,
+ trait_pred_and_suggested_ty,
);
let suggested_ty_would_satisfy_obligation = self
.evaluate_obligation_no_overflow(&new_obligation)
// Only suggest this if the expression behind the semicolon implements the predicate
&& let Some(typeck_results) = self.in_progress_typeck_results
&& let Some(ty) = typeck_results.borrow().expr_ty_opt(expr)
- && self.predicate_may_hold(&self.mk_trait_obligation_with_new_self_ty(obligation.param_env, trait_pred, ty))
+ && self.predicate_may_hold(&self.mk_trait_obligation_with_new_self_ty(
+ obligation.param_env, trait_pred.map_bound(|trait_pred| (trait_pred, ty))
+ ))
{
err.span_label(
expr.span,
expected_ref: ty::PolyTraitRef<'tcx>,
found: ty::PolyTraitRef<'tcx>,
) -> DiagnosticBuilder<'tcx, ErrorGuaranteed> {
- crate fn build_fn_sig_string<'tcx>(
+ pub(crate) fn build_fn_sig_string<'tcx>(
tcx: TyCtxt<'tcx>,
trait_ref: ty::PolyTraitRef<'tcx>,
) -> String {
debug!("maybe_note_obligation_cause_for_async_await: code={:?}", code);
match code {
ObligationCauseCode::FunctionArgumentObligation { parent_code, .. } => {
- next_code = Some(parent_code.as_ref());
+ next_code = Some(parent_code);
}
ObligationCauseCode::ImplDerivedObligation(cause) => {
let ty = cause.derived.parent_trait_pred.skip_binder().self_ty();
_ => {}
}
- next_code = Some(cause.derived.parent_code.as_ref());
+ next_code = Some(&cause.derived.parent_code);
}
ObligationCauseCode::DerivedObligation(derived_obligation)
| ObligationCauseCode::BuiltinDerivedObligation(derived_obligation) => {
_ => {}
}
- next_code = Some(derived_obligation.parent_code.as_ref());
+ next_code = Some(&derived_obligation.parent_code);
}
_ => break,
}
let is_upvar_tys_infer_tuple = if !matches!(ty.kind(), ty::Tuple(..)) {
false
} else {
- if let ObligationCauseCode::BuiltinDerivedObligation(ref data) =
- *data.parent_code
+ if let ObligationCauseCode::BuiltinDerivedObligation(data) = &*data.parent_code
{
let parent_trait_ref =
self.resolve_vars_if_possible(data.parent_trait_pred);
err,
&parent_predicate,
param_env,
- &cause_code.peel_derives(),
+ cause_code.peel_derives(),
obligated_types,
seen_requirements,
)
);
let try_obligation = self.mk_trait_obligation_with_new_self_ty(
obligation.param_env,
- trait_pred,
- normalized_ty.ty().unwrap(),
+ trait_pred.map_bound(|trait_pred| (trait_pred, normalized_ty.ty().unwrap())),
);
debug!("suggest_await_before_try: try_trait_obligation {:?}", try_obligation);
if self.predicate_may_hold(&try_obligation)
projects / rust.git / blobdiff