Statically ensure report_selection_error actually reports an error

This commit is contained in:
Oli Scherer 2024-01-25 16:23:53 +00:00
parent 646c8fc2c1
commit 2b60e56e1f
3 changed files with 120 additions and 117 deletions

View File

@ -99,7 +99,7 @@ pub trait TypeErrCtxtExt<'tcx> {
obligation: PredicateObligation<'tcx>,
root_obligation: &PredicateObligation<'tcx>,
error: &SelectionError<'tcx>,
);
) -> ErrorGuaranteed;
fn emit_specialized_closure_kind_error(
&self,
@ -208,10 +208,12 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
}
}
let mut reported = None;
for from_expansion in [false, true] {
for (error, suppressed) in iter::zip(&errors, &is_suppressed) {
if !suppressed && error.obligation.cause.span.from_expansion() == from_expansion {
self.report_fulfillment_error(error);
reported = Some(self.report_fulfillment_error(error));
// We want to ignore desugarings here: spans are equivalent even
// if one is the result of a desugaring and the other is not.
let mut span = error.obligation.cause.span;
@ -228,7 +230,10 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
}
}
self.dcx().delayed_bug("expected fulfillment errors")
// It could be that we don't report an error because we have seen an `ErrorReported` from another source.
// We should probably be able to fix most of these, but some are delayed bugs that get a proper error
// after this function.
reported.unwrap_or_else(|| self.dcx().delayed_bug("failed to report fulfillment errors"))
}
/// Reports that an overflow has occurred and halts compilation. We
@ -374,7 +379,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
mut obligation: PredicateObligation<'tcx>,
root_obligation: &PredicateObligation<'tcx>,
error: &SelectionError<'tcx>,
) {
) -> ErrorGuaranteed {
let tcx = self.tcx;
if tcx.sess.opts.unstable_opts.next_solver.map(|c| c.dump_tree).unwrap_or_default()
@ -384,10 +389,6 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
}
let mut span = obligation.cause.span;
// FIXME: statically guarantee this by tainting after the diagnostic is emitted
self.set_tainted_by_errors(
tcx.dcx().span_delayed_bug(span, "`report_selection_error` did not emit an error"),
);
let mut err = match *error {
SelectionError::Unimplemented => {
@ -412,21 +413,19 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
kind: _,
} = *obligation.cause.code()
{
self.report_extra_impl_obligation(
return self.report_extra_impl_obligation(
span,
impl_item_def_id,
trait_item_def_id,
&format!("`{}`", obligation.predicate),
)
.emit();
return;
.emit()
}
// Report a const-param specific error
if let ObligationCauseCode::ConstParam(ty) = *obligation.cause.code().peel_derives()
{
self.report_const_param_not_wf(ty, &obligation).emit();
return;
return self.report_const_param_not_wf(ty, &obligation).emit();
}
let bound_predicate = obligation.predicate.kind();
@ -436,22 +435,22 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
let trait_predicate = self.resolve_vars_if_possible(trait_predicate);
let trait_ref = trait_predicate.to_poly_trait_ref();
if let Some(_guar) = self.emit_specialized_closure_kind_error(&obligation, trait_ref) {
return;
if let Some(guar) = self.emit_specialized_closure_kind_error(&obligation, trait_ref) {
return guar;
}
// FIXME(effects)
let predicate_is_const = false;
if self.dcx().has_errors().is_some()
if let Some(guar) = self.dcx().has_errors()
&& trait_predicate.references_error()
{
return;
return guar;
}
if self.fn_arg_obligation(&obligation) {
// Silence redundant errors on binding acccess that are already
// reported on the binding definition (#56607).
return;
return self.dcx().span_delayed_bug(obligation.cause.span, "error already reported");
}
let mut file = None;
let (post_message, pre_message, type_def) = self
@ -515,7 +514,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
trait_ref,
span,
) {
GetSafeTransmuteErrorAndReason::Silent => return,
GetSafeTransmuteErrorAndReason::Silent => return self.dcx().span_delayed_bug(span, "silent safe transmute error"),
GetSafeTransmuteErrorAndReason::Error {
err_msg,
safe_transmute_explanation,
@ -576,8 +575,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
have_alt_message,
) {
self.note_obligation_cause(&mut err, &obligation);
err.emit();
return;
return err.emit();
}
file_note.map(|note| err.note(note));
@ -680,13 +678,11 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
}
if self.suggest_add_clone_to_arg(&obligation, &mut err, trait_predicate) {
err.emit();
return;
return err.emit();
}
if self.suggest_impl_trait(&mut err, &obligation, trait_predicate) {
err.emit();
return;
return err.emit();
}
if is_unsize {
@ -776,8 +772,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
Some(sym::Debug | sym::Display)
)
{
err.emit();
return;
return err.emit();
}
err
@ -912,8 +907,8 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
found_trait_ref,
expected_trait_ref,
) {
Some(err) => err,
None => return,
Ok(err) => err,
Err(guar) => return guar,
}
}
@ -934,15 +929,15 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
}
SelectionError::NotConstEvaluatable(NotConstEvaluatable::MentionsParam) => {
match self.report_not_const_evaluatable_error(&obligation, span) {
Some(err) => err,
None => return,
Ok(err) => err,
Err(guar) => return guar,
}
}
// Already reported in the query.
SelectionError::NotConstEvaluatable(NotConstEvaluatable::Error(_)) |
SelectionError::NotConstEvaluatable(NotConstEvaluatable::Error(guar)) |
// Already reported.
Overflow(OverflowError::Error(_)) => return,
Overflow(OverflowError::Error(guar)) => return guar,
Overflow(_) => {
bug!("overflow should be handled before the `report_selection_error` path");
@ -951,7 +946,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
self.note_obligation_cause(&mut err, &obligation);
self.point_at_returns_when_relevant(&mut err, &obligation);
err.emit();
err.emit()
}
fn emit_specialized_closure_kind_error(
@ -1323,13 +1318,13 @@ pub(super) trait InferCtxtPrivExt<'tcx> {
// `error` occurring implies that `cond` occurs.
fn error_implies(&self, cond: ty::Predicate<'tcx>, error: ty::Predicate<'tcx>) -> bool;
fn report_fulfillment_error(&self, error: &FulfillmentError<'tcx>);
fn report_fulfillment_error(&self, error: &FulfillmentError<'tcx>) -> ErrorGuaranteed;
fn report_projection_error(
&self,
obligation: &PredicateObligation<'tcx>,
error: &MismatchedProjectionTypes<'tcx>,
);
) -> ErrorGuaranteed;
fn maybe_detailed_projection_msg(
&self,
@ -1395,7 +1390,7 @@ pub(super) trait InferCtxtPrivExt<'tcx> {
trait_ref_and_ty: ty::Binder<'tcx, (ty::TraitPredicate<'tcx>, Ty<'tcx>)>,
) -> PredicateObligation<'tcx>;
fn maybe_report_ambiguity(&self, obligation: &PredicateObligation<'tcx>);
fn maybe_report_ambiguity(&self, obligation: &PredicateObligation<'tcx>) -> ErrorGuaranteed;
fn predicate_can_apply(
&self,
@ -1512,13 +1507,13 @@ pub(super) trait InferCtxtPrivExt<'tcx> {
span: Span,
found_trait_ref: ty::Binder<'tcx, ty::TraitRef<'tcx>>,
expected_trait_ref: ty::Binder<'tcx, ty::TraitRef<'tcx>>,
) -> Option<DiagnosticBuilder<'tcx>>;
) -> Result<DiagnosticBuilder<'tcx>, ErrorGuaranteed>;
fn report_not_const_evaluatable_error(
&self,
obligation: &PredicateObligation<'tcx>,
span: Span,
) -> Option<DiagnosticBuilder<'tcx>>;
) -> Result<DiagnosticBuilder<'tcx>, ErrorGuaranteed>;
}
impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
@ -1564,7 +1559,7 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
}
#[instrument(skip(self), level = "debug")]
fn report_fulfillment_error(&self, error: &FulfillmentError<'tcx>) {
fn report_fulfillment_error(&self, error: &FulfillmentError<'tcx>) -> ErrorGuaranteed {
if self.tcx.sess.opts.unstable_opts.next_solver.map(|c| c.dump_tree).unwrap_or_default()
== DumpSolverProofTree::OnError
{
@ -1572,31 +1567,29 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
}
match error.code {
FulfillmentErrorCode::SelectionError(ref selection_error) => {
self.report_selection_error(
FulfillmentErrorCode::SelectionError(ref selection_error) => self
.report_selection_error(
error.obligation.clone(),
&error.root_obligation,
selection_error,
);
}
),
FulfillmentErrorCode::ProjectionError(ref e) => {
self.report_projection_error(&error.obligation, e);
self.report_projection_error(&error.obligation, e)
}
FulfillmentErrorCode::Ambiguity { overflow: false } => {
self.maybe_report_ambiguity(&error.obligation);
self.maybe_report_ambiguity(&error.obligation)
}
FulfillmentErrorCode::Ambiguity { overflow: true } => {
self.report_overflow_no_abort(error.obligation.clone());
self.report_overflow_no_abort(error.obligation.clone())
}
FulfillmentErrorCode::SubtypeError(ref expected_found, ref err) => {
self.report_mismatched_types(
FulfillmentErrorCode::SubtypeError(ref expected_found, ref err) => self
.report_mismatched_types(
&error.obligation.cause,
expected_found.expected,
expected_found.found,
*err,
)
.emit();
}
.emit(),
FulfillmentErrorCode::ConstEquateError(ref expected_found, ref err) => {
let mut diag = self.report_mismatched_consts(
&error.obligation.cause,
@ -1620,11 +1613,9 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
&mut Default::default(),
);
}
diag.emit();
}
FulfillmentErrorCode::Cycle(ref cycle) => {
self.report_overflow_obligation_cycle(cycle);
diag.emit()
}
FulfillmentErrorCode::Cycle(ref cycle) => self.report_overflow_obligation_cycle(cycle),
}
}
@ -1633,11 +1624,11 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
&self,
obligation: &PredicateObligation<'tcx>,
error: &MismatchedProjectionTypes<'tcx>,
) {
) -> ErrorGuaranteed {
let predicate = self.resolve_vars_if_possible(obligation.predicate);
if predicate.references_error() {
return;
if let Err(e) = predicate.error_reported() {
return e;
}
self.probe(|_| {
@ -1802,8 +1793,8 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
false,
);
self.note_obligation_cause(&mut diag, obligation);
diag.emit();
});
diag.emit()
})
}
fn maybe_detailed_projection_msg(
@ -2341,7 +2332,7 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
}
#[instrument(skip(self), level = "debug")]
fn maybe_report_ambiguity(&self, obligation: &PredicateObligation<'tcx>) {
fn maybe_report_ambiguity(&self, obligation: &PredicateObligation<'tcx>) -> ErrorGuaranteed {
// Unable to successfully determine, probably means
// insufficient type information, but could mean
// ambiguous impls. The latter *ought* to be a
@ -2361,8 +2352,8 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
let trait_ref = bound_predicate.rebind(data.trait_ref);
debug!(?trait_ref);
if predicate.references_error() {
return;
if let Err(e) = predicate.error_reported() {
return e;
}
// This is kind of a hack: it frequently happens that some earlier
@ -2381,7 +2372,8 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
// check upstream for type errors and don't add the obligations to
// begin with in those cases.
if self.tcx.lang_items().sized_trait() == Some(trait_ref.def_id()) {
if let None = self.tainted_by_errors() {
match self.tainted_by_errors() {
None => {
let err = self.emit_inference_failure_err(
obligation.cause.body_id,
span,
@ -2390,8 +2382,10 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
false,
);
err.stash(span, StashKey::MaybeForgetReturn);
return self.dcx().delayed_bug("stashed error never reported");
}
Some(e) => return e,
}
return;
}
// Typically, this ambiguity should only happen if
@ -2450,19 +2444,21 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
}
}
if ambiguities.len() > 1 && ambiguities.len() < 10 && has_non_region_infer {
if self.tainted_by_errors().is_some() && subst.is_none() {
if let Some(e) = self.tainted_by_errors()
&& subst.is_none()
{
// If `subst.is_none()`, then this is probably two param-env
// candidates or impl candidates that are equal modulo lifetimes.
// Therefore, if we've already emitted an error, just skip this
// one, since it's not particularly actionable.
err.cancel();
return;
return e;
}
self.annotate_source_of_ambiguity(&mut err, &ambiguities, predicate);
} else {
if self.tainted_by_errors().is_some() {
if let Some(e) = self.tainted_by_errors() {
err.cancel();
return;
return e;
}
err.note(format!("cannot satisfy `{predicate}`"));
let impl_candidates = self
@ -2605,11 +2601,15 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
ty::PredicateKind::Clause(ty::ClauseKind::WellFormed(arg)) => {
// Same hacky approach as above to avoid deluging user
// with error messages.
if arg.references_error()
|| self.dcx().has_errors().is_some()
|| self.tainted_by_errors().is_some()
{
return;
if let Err(e) = arg.error_reported() {
return e;
}
if let Some(e) = self.tainted_by_errors() {
return e;
}
if let Some(e) = self.dcx().has_errors() {
return e;
}
self.emit_inference_failure_err(
@ -2622,12 +2622,15 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
}
ty::PredicateKind::Subtype(data) => {
if data.references_error()
|| self.dcx().has_errors().is_some()
|| self.tainted_by_errors().is_some()
{
if let Err(e) = data.error_reported() {
return e;
}
if let Some(e) = self.tainted_by_errors() {
return e;
}
if let Some(e) = self.dcx().has_errors() {
// no need to overload user in such cases
return;
return e;
}
let SubtypePredicate { a_is_expected: _, a, b } = data;
// both must be type variables, or the other would've been instantiated
@ -2641,8 +2644,11 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
)
}
ty::PredicateKind::Clause(ty::ClauseKind::Projection(data)) => {
if predicate.references_error() || self.tainted_by_errors().is_some() {
return;
if let Err(e) = predicate.error_reported() {
return e;
}
if let Some(e) = self.tainted_by_errors() {
return e;
}
let subst = data
.projection_ty
@ -2673,8 +2679,11 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
}
ty::PredicateKind::Clause(ty::ClauseKind::ConstEvaluatable(data)) => {
if predicate.references_error() || self.tainted_by_errors().is_some() {
return;
if let Err(e) = predicate.error_reported() {
return e;
}
if let Some(e) = self.tainted_by_errors() {
return e;
}
let subst = data.walk().find(|g| g.is_non_region_infer());
if let Some(subst) = subst {
@ -2699,8 +2708,12 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
}
}
_ => {
if self.dcx().has_errors().is_some() || self.tainted_by_errors().is_some() {
return;
if let Some(e) = self.tainted_by_errors() {
return e;
}
if let Some(e) = self.dcx().has_errors() {
// no need to overload user in such cases
return e;
}
struct_span_code_err!(
self.dcx(),
@ -2713,7 +2726,7 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
}
};
self.note_obligation_cause(&mut err, obligation);
err.emit();
err.emit()
}
fn annotate_source_of_ambiguity(
@ -3433,16 +3446,14 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
span: Span,
found_trait_ref: ty::Binder<'tcx, ty::TraitRef<'tcx>>,
expected_trait_ref: ty::Binder<'tcx, ty::TraitRef<'tcx>>,
) -> Option<DiagnosticBuilder<'tcx>> {
) -> Result<DiagnosticBuilder<'tcx>, ErrorGuaranteed> {
let found_trait_ref = self.resolve_vars_if_possible(found_trait_ref);
let expected_trait_ref = self.resolve_vars_if_possible(expected_trait_ref);
if expected_trait_ref.self_ty().references_error() {
return None;
}
expected_trait_ref.self_ty().error_reported()?;
let Some(found_trait_ty) = found_trait_ref.self_ty().no_bound_vars() else {
return None;
return Err(self.dcx().delayed_bug("bound vars outside binder"));
};
let found_did = match *found_trait_ty.kind() {
@ -3456,7 +3467,7 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
if !self.reported_signature_mismatch.borrow_mut().insert((span, found_span)) {
// We check closures twice, with obligations flowing in different directions,
// but we want to complain about them only once.
return None;
return Err(self.dcx().span_delayed_bug(span, "already_reported"));
}
let mut not_tupled = false;
@ -3485,7 +3496,7 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
// This shouldn't be common unless manually implementing one of the
// traits manually, but don't make it more confusing when it does
// happen.
Some(
Ok(
if Some(expected_trait_ref.def_id()) != self.tcx.lang_items().coroutine_trait()
&& not_tupled
{
@ -3534,9 +3545,10 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
&self,
obligation: &PredicateObligation<'tcx>,
span: Span,
) -> Option<DiagnosticBuilder<'tcx>> {
) -> Result<DiagnosticBuilder<'tcx>, ErrorGuaranteed> {
if !self.tcx.features().generic_const_exprs {
self.dcx()
let guar = self
.dcx()
.struct_span_err(span, "constant expression depends on a generic parameter")
// FIXME(const_generics): we should suggest to the user how they can resolve this
// issue. However, this is currently not actually possible
@ -3546,7 +3558,7 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
// be reachable.
.with_note("this may fail depending on what value the parameter takes")
.emit();
return None;
return Err(guar);
}
match obligation.predicate.kind().skip_binder() {
@ -3561,13 +3573,13 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
)),
_ => err.help("consider adding a `where` bound using this expression"),
};
Some(err)
Ok(err)
}
ty::ConstKind::Expr(_) => {
let err = self
.dcx()
.struct_span_err(span, format!("unconstrained generic constant `{ct}`"));
Some(err)
Ok(err)
}
_ => {
bug!("const evaluatable failed for non-unevaluated const `{ct:?}`");

View File

@ -6,6 +6,5 @@ fn main() {}
fn f() -> impl Foo {
//~^ ERROR the trait bound `i32: Foo` is not satisfied
//~| ERROR `report_selection_error` did not emit an error
1i32
}

View File

@ -1,9 +1,3 @@
error: `report_selection_error` did not emit an error
--> $DIR/eagerly-emit.rs:7:11
|
LL | fn f() -> impl Foo {
| ^^^^^^^^
error: trimmed_def_paths constructed but no error emitted; use `DelayDm` for lints or `with_no_trimmed_paths` for debugging
error[E0277]: the trait bound `i32: Foo` is not satisfied
@ -11,7 +5,7 @@ error[E0277]: the trait bound `i32: Foo` is not satisfied
|
LL | fn f() -> impl Foo {
| ^^^^^^^^ the trait `Foo` is not implemented for `i32`
...
LL |
LL | 1i32
| ---- return type was inferred to be `i32` here
|
@ -21,8 +15,6 @@ help: this trait has no implementations, consider adding one
LL | trait Foo {}
| ^^^^^^^^^
error: expected fulfillment errors
error: aborting due to 4 previous errors
error: aborting due to 2 previous errors
For more information about this error, try `rustc --explain E0277`.