diff options
Diffstat (limited to 'compiler/rustc_trait_selection/src')
5 files changed, 16 insertions, 112 deletions
diff --git a/compiler/rustc_trait_selection/src/traits/auto_trait.rs b/compiler/rustc_trait_selection/src/traits/auto_trait.rs index 90ff07cba02..49434ec1428 100644 --- a/compiler/rustc_trait_selection/src/traits/auto_trait.rs +++ b/compiler/rustc_trait_selection/src/traits/auto_trait.rs @@ -212,15 +212,7 @@ impl<'tcx> AutoTraitFinder<'tcx> { panic!("Unable to fulfill trait {:?} for '{:?}': {:?}", trait_did, ty, errors); } - let body_id_map: FxHashMap<_, _> = infcx - .inner - .borrow() - .region_obligations() - .iter() - .map(|&(id, _)| (id, vec![])) - .collect(); - - infcx.process_registered_region_obligations(&body_id_map, full_env); + infcx.process_registered_region_obligations(&Default::default(), full_env); let region_data = infcx .inner diff --git a/compiler/rustc_trait_selection/src/traits/coherence.rs b/compiler/rustc_trait_selection/src/traits/coherence.rs index 2b26b916d32..ae69f2f7eb3 100644 --- a/compiler/rustc_trait_selection/src/traits/coherence.rs +++ b/compiler/rustc_trait_selection/src/traits/coherence.rs @@ -16,7 +16,6 @@ use crate::traits::{ //use rustc_data_structures::fx::FxHashMap; use rustc_errors::Diagnostic; use rustc_hir::def_id::{DefId, LOCAL_CRATE}; -use rustc_hir::CRATE_HIR_ID; use rustc_infer::infer::{InferCtxt, TyCtxtInferExt}; use rustc_infer::traits::{util, TraitEngine}; use rustc_middle::traits::specialization_graph::OverlapMode; @@ -317,14 +316,13 @@ fn negative_impl<'cx, 'tcx>( let (subject2, obligations) = impl_subject_and_oblig(selcx, impl_env, impl2_def_id, impl2_substs); - !equate(&infcx, impl_env, impl1_def_id, subject1, subject2, obligations) + !equate(&infcx, impl_env, subject1, subject2, obligations) }) } fn equate<'cx, 'tcx>( infcx: &InferCtxt<'cx, 'tcx>, impl_env: ty::ParamEnv<'tcx>, - impl1_def_id: DefId, subject1: ImplSubject<'tcx>, subject2: ImplSubject<'tcx>, obligations: impl Iterator<Item = PredicateObligation<'tcx>>, @@ -341,7 +339,7 @@ fn equate<'cx, 'tcx>( let opt_failing_obligation = obligations .into_iter() .chain(more_obligations) - .find(|o| negative_impl_exists(selcx, impl_env, impl1_def_id, o)); + .find(|o| negative_impl_exists(selcx, impl_env, o)); if let Some(failing_obligation) = opt_failing_obligation { debug!("overlap: obligation unsatisfiable {:?}", failing_obligation); @@ -356,18 +354,17 @@ fn equate<'cx, 'tcx>( fn negative_impl_exists<'cx, 'tcx>( selcx: &SelectionContext<'cx, 'tcx>, param_env: ty::ParamEnv<'tcx>, - region_context: DefId, o: &PredicateObligation<'tcx>, ) -> bool { let infcx = &selcx.infcx().fork(); - if resolve_negative_obligation(infcx, param_env, region_context, o) { + if resolve_negative_obligation(infcx, param_env, o) { return true; } // Try to prove a negative obligation exists for super predicates for o in util::elaborate_predicates(infcx.tcx, iter::once(o.predicate)) { - if resolve_negative_obligation(infcx, param_env, region_context, &o) { + if resolve_negative_obligation(infcx, param_env, &o) { return true; } } @@ -379,7 +376,6 @@ fn negative_impl_exists<'cx, 'tcx>( fn resolve_negative_obligation<'cx, 'tcx>( infcx: &InferCtxt<'cx, 'tcx>, param_env: ty::ParamEnv<'tcx>, - region_context: DefId, o: &PredicateObligation<'tcx>, ) -> bool { let tcx = infcx.tcx; @@ -397,19 +393,11 @@ fn resolve_negative_obligation<'cx, 'tcx>( return false; } - let mut outlives_env = OutlivesEnvironment::new(param_env); - // FIXME -- add "assumed to be well formed" types into the `outlives_env` - - // "Save" the accumulated implied bounds into the outlives environment - // (due to the FIXME above, there aren't any, but this step is still needed). - // The "body id" is given as `CRATE_HIR_ID`, which is the same body-id used - // by the "dummy" causes elsewhere (body-id is only relevant when checking - // function bodies with closures). - outlives_env.save_implied_bounds(CRATE_HIR_ID); - - infcx.process_registered_region_obligations(outlives_env.region_bound_pairs_map(), param_env); + // FIXME -- also add "assumed to be well formed" types into the `outlives_env` + let outlives_env = OutlivesEnvironment::new(param_env); + infcx.process_registered_region_obligations(outlives_env.region_bound_pairs(), param_env); - let errors = infcx.resolve_regions(region_context, &outlives_env); + let errors = infcx.resolve_regions(&outlives_env); if !errors.is_empty() { return false; diff --git a/compiler/rustc_trait_selection/src/traits/mod.rs b/compiler/rustc_trait_selection/src/traits/mod.rs index 34b0f431b8e..b45f72e8748 100644 --- a/compiler/rustc_trait_selection/src/traits/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/mod.rs @@ -198,17 +198,13 @@ pub fn type_known_to_meet_bound_modulo_regions<'a, 'tcx>( } } +#[instrument(level = "debug", skip(tcx, elaborated_env))] fn do_normalize_predicates<'tcx>( tcx: TyCtxt<'tcx>, - region_context: DefId, cause: ObligationCause<'tcx>, elaborated_env: ty::ParamEnv<'tcx>, predicates: Vec<ty::Predicate<'tcx>>, ) -> Result<Vec<ty::Predicate<'tcx>>, ErrorGuaranteed> { - debug!( - "do_normalize_predicates(predicates={:?}, region_context={:?}, cause={:?})", - predicates, region_context, cause, - ); let span = cause.span; tcx.infer_ctxt().enter(|infcx| { // FIXME. We should really... do something with these region @@ -240,7 +236,7 @@ fn do_normalize_predicates<'tcx>( // cares about declarations like `'a: 'b`. let outlives_env = OutlivesEnvironment::new(elaborated_env); - infcx.resolve_regions_and_report_errors(region_context, &outlives_env); + infcx.resolve_regions_and_report_errors(&outlives_env); let predicates = match infcx.fully_resolve(predicates) { Ok(predicates) => predicates, @@ -269,9 +265,9 @@ fn do_normalize_predicates<'tcx>( // FIXME: this is gonna need to be removed ... /// Normalizes the parameter environment, reporting errors if they occur. +#[instrument(level = "debug", skip(tcx))] pub fn normalize_param_env_or_error<'tcx>( tcx: TyCtxt<'tcx>, - region_context: DefId, unnormalized_env: ty::ParamEnv<'tcx>, cause: ObligationCause<'tcx>, ) -> ty::ParamEnv<'tcx> { @@ -289,12 +285,6 @@ pub fn normalize_param_env_or_error<'tcx>( // parameter environments once for every fn as it goes, // and errors will get reported then; so outside of type inference we // can be sure that no errors should occur. - - debug!( - "normalize_param_env_or_error(region_context={:?}, unnormalized_env={:?}, cause={:?})", - region_context, unnormalized_env, cause - ); - let mut predicates: Vec<_> = util::elaborate_predicates(tcx, unnormalized_env.caller_bounds().into_iter()) .map(|obligation| obligation.predicate) @@ -338,7 +328,6 @@ pub fn normalize_param_env_or_error<'tcx>( ); let Ok(non_outlives_predicates) = do_normalize_predicates( tcx, - region_context, cause.clone(), elaborated_env, predicates, @@ -362,7 +351,6 @@ pub fn normalize_param_env_or_error<'tcx>( ); let Ok(outlives_predicates) = do_normalize_predicates( tcx, - region_context, cause, outlives_env, outlives_predicates, diff --git a/compiler/rustc_trait_selection/src/traits/query/dropck_outlives.rs b/compiler/rustc_trait_selection/src/traits/query/dropck_outlives.rs index 25cc6e9f9f2..aad3c37f84e 100644 --- a/compiler/rustc_trait_selection/src/traits/query/dropck_outlives.rs +++ b/compiler/rustc_trait_selection/src/traits/query/dropck_outlives.rs @@ -1,73 +1,7 @@ -use crate::infer::at::At; -use crate::infer::canonical::OriginalQueryValues; -use crate::infer::InferOk; - -use rustc_middle::ty::subst::GenericArg; use rustc_middle::ty::{self, Ty, TyCtxt}; pub use rustc_middle::traits::query::{DropckConstraint, DropckOutlivesResult}; -pub trait AtExt<'tcx> { - fn dropck_outlives(&self, ty: Ty<'tcx>) -> InferOk<'tcx, Vec<GenericArg<'tcx>>>; -} - -impl<'cx, 'tcx> AtExt<'tcx> for At<'cx, 'tcx> { - /// Given a type `ty` of some value being dropped, computes a set - /// of "kinds" (types, regions) that must be outlive the execution - /// of the destructor. These basically correspond to data that the - /// destructor might access. This is used during regionck to - /// impose "outlives" constraints on any lifetimes referenced - /// within. - /// - /// The rules here are given by the "dropck" RFCs, notably [#1238] - /// and [#1327]. This is a fixed-point computation, where we - /// explore all the data that will be dropped (transitively) when - /// a value of type `ty` is dropped. For each type T that will be - /// dropped and which has a destructor, we must assume that all - /// the types/regions of T are live during the destructor, unless - /// they are marked with a special attribute (`#[may_dangle]`). - /// - /// [#1238]: https://github.com/rust-lang/rfcs/blob/master/text/1238-nonparametric-dropck.md - /// [#1327]: https://github.com/rust-lang/rfcs/blob/master/text/1327-dropck-param-eyepatch.md - fn dropck_outlives(&self, ty: Ty<'tcx>) -> InferOk<'tcx, Vec<GenericArg<'tcx>>> { - debug!("dropck_outlives(ty={:?}, param_env={:?})", ty, self.param_env,); - - // Quick check: there are a number of cases that we know do not require - // any destructor. - let tcx = self.infcx.tcx; - if trivial_dropck_outlives(tcx, ty) { - return InferOk { value: vec![], obligations: vec![] }; - } - - let mut orig_values = OriginalQueryValues::default(); - let c_ty = self.infcx.canonicalize_query(self.param_env.and(ty), &mut orig_values); - let span = self.cause.span; - debug!("c_ty = {:?}", c_ty); - if let Ok(result) = tcx.dropck_outlives(c_ty) - && result.is_proven() - && let Ok(InferOk { value, obligations }) = - self.infcx.instantiate_query_response_and_region_obligations( - self.cause, - self.param_env, - &orig_values, - result, - ) - { - let ty = self.infcx.resolve_vars_if_possible(ty); - let kinds = value.into_kinds_reporting_overflows(tcx, span, ty); - return InferOk { value: kinds, obligations }; - } - - // Errors and ambiguity in dropck occur in two cases: - // - unresolved inference variables at the end of typeck - // - non well-formed types where projections cannot be resolved - // Either of these should have created an error before. - tcx.sess.delay_span_bug(span, "dtorck encountered internal error"); - - InferOk { value: vec![], obligations: vec![] } - } -} - /// This returns true if the type `ty` is "trivial" for /// dropck-outlives -- that is, if it doesn't require any types to /// outlive. This is similar but not *quite* the same as the @@ -79,6 +13,8 @@ impl<'cx, 'tcx> AtExt<'tcx> for At<'cx, 'tcx> { /// /// Note also that `needs_drop` requires a "global" type (i.e., one /// with erased regions), but this function does not. +/// +// FIXME(@lcnr): remove this module and move this function somewhere else. pub fn trivial_dropck_outlives<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> bool { match ty.kind() { // None of these types have a destructor and hence they do not @@ -105,7 +41,7 @@ pub fn trivial_dropck_outlives<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> bool { ty::Array(ty, _) | ty::Slice(ty) => trivial_dropck_outlives(tcx, *ty), // (T1..Tn) and closures have same properties as T1..Tn -- - // check if *any* of those are trivial. + // check if *all* of them are trivial. ty::Tuple(tys) => tys.iter().all(|t| trivial_dropck_outlives(tcx, t)), ty::Closure(_, ref substs) => { trivial_dropck_outlives(tcx, substs.as_closure().tupled_upvars_ty()) diff --git a/compiler/rustc_trait_selection/src/traits/query/type_op/custom.rs b/compiler/rustc_trait_selection/src/traits/query/type_op/custom.rs index 605c9ace5ed..c9d46b2810d 100644 --- a/compiler/rustc_trait_selection/src/traits/query/type_op/custom.rs +++ b/compiler/rustc_trait_selection/src/traits/query/type_op/custom.rs @@ -95,7 +95,7 @@ pub fn scrape_region_constraints<'tcx, Op: super::TypeOp<'tcx, Output = R>, R>( infcx.tcx, region_obligations .iter() - .map(|(_, r_o)| (r_o.sup_type, r_o.sub_region)) + .map(|r_o| (r_o.sup_type, r_o.sub_region)) .map(|(ty, r)| (infcx.resolve_vars_if_possible(ty), r)), ®ion_constraint_data, ); |