diff --git a/compiler/rustc_infer/src/infer/mod.rs b/compiler/rustc_infer/src/infer/mod.rs index fa8dea064daaa..5fc44b8f356b5 100644 --- a/compiler/rustc_infer/src/infer/mod.rs +++ b/compiler/rustc_infer/src/infer/mod.rs @@ -27,6 +27,7 @@ use rustc_middle::bug; use rustc_middle::infer::canonical::{CanonicalQueryInput, CanonicalVarValues}; use rustc_middle::mir::ConstraintCategory; use rustc_middle::traits::select; +use rustc_middle::traits::solve::Goal; use rustc_middle::ty::error::{ExpectedFound, TypeError}; use rustc_middle::ty::{ self, BoundVarReplacerDelegate, ConstVid, FloatVid, GenericArg, GenericArgKind, GenericArgs, @@ -268,7 +269,7 @@ pub struct InferCtxt<'tcx> { /// The set of predicates on which errors have been reported, to /// avoid reporting the same error twice. pub reported_trait_errors: - RefCell>, ErrorGuaranteed)>>, + RefCell>>, ErrorGuaranteed)>>, pub reported_signature_mismatch: RefCell)>>, diff --git a/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs b/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs index 73ae5177c4895..bc45fc11e9bbe 100644 --- a/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs +++ b/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs @@ -14,6 +14,7 @@ use rustc_hir::def_id::{DefId, LOCAL_CRATE, LocalDefId}; use rustc_hir::intravisit::Visitor; use rustc_hir::{self as hir, LangItem, Node}; use rustc_infer::infer::{InferOk, TypeTrace}; +use rustc_infer::traits::solve::Goal; use rustc_middle::traits::SignatureMismatchData; use rustc_middle::traits::select::OverflowError; use rustc_middle::ty::abstract_const::NotConstEvaluatable; @@ -930,7 +931,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> { )) = arg.kind && let Node::Pat(pat) = self.tcx.hir_node(*hir_id) && let Some((preds, guar)) = self.reported_trait_errors.borrow().get(&pat.span) - && preds.contains(&obligation.predicate) + && preds.contains(&obligation.as_goal()) { return Err(*guar); } @@ -1292,6 +1293,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> { impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> { fn can_match_trait( &self, + param_env: ty::ParamEnv<'tcx>, goal: ty::TraitPredicate<'tcx>, assumption: ty::PolyTraitPredicate<'tcx>, ) -> bool { @@ -1306,11 +1308,12 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> { assumption, ); - self.can_eq(ty::ParamEnv::empty(), goal.trait_ref, trait_assumption.trait_ref) + self.can_eq(param_env, goal.trait_ref, trait_assumption.trait_ref) } fn can_match_projection( &self, + param_env: ty::ParamEnv<'tcx>, goal: ty::ProjectionPredicate<'tcx>, assumption: ty::PolyProjectionPredicate<'tcx>, ) -> bool { @@ -1320,7 +1323,6 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> { assumption, ); - let param_env = ty::ParamEnv::empty(); self.can_eq(param_env, goal.projection_term, assumption.projection_term) && self.can_eq(param_env, goal.term, assumption.term) } @@ -1330,24 +1332,32 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> { #[instrument(level = "debug", skip(self), ret)] pub(super) fn error_implies( &self, - cond: ty::Predicate<'tcx>, - error: ty::Predicate<'tcx>, + cond: Goal<'tcx, ty::Predicate<'tcx>>, + error: Goal<'tcx, ty::Predicate<'tcx>>, ) -> bool { if cond == error { return true; } - if let Some(error) = error.as_trait_clause() { + // FIXME: We could be smarter about this, i.e. if cond's param-env is a + // subset of error's param-env. This only matters when binders will carry + // predicates though, and obviously only matters for error reporting. + if cond.param_env != error.param_env { + return false; + } + let param_env = error.param_env; + + if let Some(error) = error.predicate.as_trait_clause() { self.enter_forall(error, |error| { - elaborate(self.tcx, std::iter::once(cond)) + elaborate(self.tcx, std::iter::once(cond.predicate)) .filter_map(|implied| implied.as_trait_clause()) - .any(|implied| self.can_match_trait(error, implied)) + .any(|implied| self.can_match_trait(param_env, error, implied)) }) - } else if let Some(error) = error.as_projection_clause() { + } else if let Some(error) = error.predicate.as_projection_clause() { self.enter_forall(error, |error| { - elaborate(self.tcx, std::iter::once(cond)) + elaborate(self.tcx, std::iter::once(cond.predicate)) .filter_map(|implied| implied.as_projection_clause()) - .any(|implied| self.can_match_projection(error, implied)) + .any(|implied| self.can_match_projection(param_env, error, implied)) }) } else { false diff --git a/compiler/rustc_trait_selection/src/error_reporting/traits/mod.rs b/compiler/rustc_trait_selection/src/error_reporting/traits/mod.rs index efee6e2aa1d45..8ff7030717a8b 100644 --- a/compiler/rustc_trait_selection/src/error_reporting/traits/mod.rs +++ b/compiler/rustc_trait_selection/src/error_reporting/traits/mod.rs @@ -12,6 +12,7 @@ use rustc_errors::{Applicability, Diag, E0038, E0276, MultiSpan, struct_span_cod use rustc_hir::def_id::{DefId, LocalDefId}; use rustc_hir::intravisit::Visitor; use rustc_hir::{self as hir, AmbigArg, LangItem}; +use rustc_infer::traits::solve::Goal; use rustc_infer::traits::{ DynCompatibilityViolation, Obligation, ObligationCause, ObligationCauseCode, PredicateObligation, SelectionError, @@ -144,7 +145,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> { #[derive(Debug)] struct ErrorDescriptor<'tcx> { - predicate: ty::Predicate<'tcx>, + goal: Goal<'tcx, ty::Predicate<'tcx>>, index: Option, // None if this is an old error } @@ -152,15 +153,8 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> { .reported_trait_errors .borrow() .iter() - .map(|(&span, predicates)| { - ( - span, - predicates - .0 - .iter() - .map(|&predicate| ErrorDescriptor { predicate, index: None }) - .collect(), - ) + .map(|(&span, goals)| { + (span, goals.0.iter().map(|&goal| ErrorDescriptor { goal, index: None }).collect()) }) .collect(); @@ -186,10 +180,10 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> { span = expn_data.call_site; } - error_map.entry(span).or_default().push(ErrorDescriptor { - predicate: error.obligation.predicate, - index: Some(index), - }); + error_map + .entry(span) + .or_default() + .push(ErrorDescriptor { goal: error.obligation.as_goal(), index: Some(index) }); } // We do this in 2 passes because we want to display errors in order, though @@ -210,9 +204,9 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> { continue; } - if self.error_implies(error2.predicate, error.predicate) + if self.error_implies(error2.goal, error.goal) && !(error2.index >= error.index - && self.error_implies(error.predicate, error2.predicate)) + && self.error_implies(error.goal, error2.goal)) { info!("skipping {:?} (implied by {:?})", error, error2); is_suppressed[index] = true; @@ -243,7 +237,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> { .entry(span) .or_insert_with(|| (vec![], guar)) .0 - .push(error.obligation.predicate); + .push(error.obligation.as_goal()); } } } diff --git a/tests/ui/const-generics/const-param-has-ty-goal-in-error-implies.rs b/tests/ui/const-generics/const-param-has-ty-goal-in-error-implies.rs new file mode 100644 index 0000000000000..231bb5252de1a --- /dev/null +++ b/tests/ui/const-generics/const-param-has-ty-goal-in-error-implies.rs @@ -0,0 +1,41 @@ +// compile-flags: -Znext-solver + +// Test for a weird diagnostics corner case. In the error reporting code, when reporting +// fulfillment errors for goals A and B, we try to see if elaborating A will result in +// another goal that can equate with B. That would signal that B is "implied by" A, +// allowing us to skip reporting it, which is beneficial for cutting down on the number +// of diagnostics we report. In the new trait solver especially, but even in the old trait +// solver through things like defining opaque type usages, this `can_equate` call was not +// properly taking the param-env of the goals, resulting in nested obligations that had +// empty param-envs. If one of these nested obligations was a `ConstParamHasTy` goal, then +// we would ICE, since those goals are particularly strict about the param-env they're +// evaluated in. + +// This is morally a fix for , but that +// repro uses details about how defining usages in the `check_opaque_well_formed` code +// can spring out of type equality, and will likely stop failing soon coincidentally once +// we start using `PostBorrowck` mode in that check. + +trait Foo: Baz<()> {} +trait Baz {} + +trait IdentityWithConstArgGoal { + type Assoc; +} +impl IdentityWithConstArgGoal for T { + type Assoc = T; +} + +fn unsatisfied() +where + T: Foo, + T: Baz<>::Assoc>, +{ +} + +fn test() { + unsatisfied::<(), N>(); + //~^ ERROR the trait bound `(): Foo` is not satisfied +} + +fn main() {} diff --git a/tests/ui/const-generics/const-param-has-ty-goal-in-error-implies.stderr b/tests/ui/const-generics/const-param-has-ty-goal-in-error-implies.stderr new file mode 100644 index 0000000000000..77bba4945523a --- /dev/null +++ b/tests/ui/const-generics/const-param-has-ty-goal-in-error-implies.stderr @@ -0,0 +1,23 @@ +error[E0277]: the trait bound `(): Foo` is not satisfied + --> $DIR/const-param-has-ty-goal-in-error-implies.rs:37:19 + | +LL | unsatisfied::<(), N>(); + | ^^ the trait `Foo` is not implemented for `()` + | +help: this trait has no implementations, consider adding one + --> $DIR/const-param-has-ty-goal-in-error-implies.rs:19:1 + | +LL | trait Foo: Baz<()> {} + | ^^^^^^^^^^^^^^^^^^ +note: required by a bound in `unsatisfied` + --> $DIR/const-param-has-ty-goal-in-error-implies.rs:31:8 + | +LL | fn unsatisfied() + | ----------- required by a bound in this function +LL | where +LL | T: Foo, + | ^^^ required by this bound in `unsatisfied` + +error: aborting due to 1 previous error + +For more information about this error, try `rustc --explain E0277`.