diff options
Diffstat (limited to 'compiler/rustc_trait_selection/src/traits/query')
4 files changed, 26 insertions, 19 deletions
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 9484a50e3..620b992ee 100644 --- a/compiler/rustc_trait_selection/src/traits/query/dropck_outlives.rs +++ b/compiler/rustc_trait_selection/src/traits/query/dropck_outlives.rs @@ -36,7 +36,6 @@ pub fn trivial_dropck_outlives<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> bool { | ty::FnPtr(_) | ty::Char | ty::GeneratorWitness(..) - | ty::GeneratorWitnessMIR(..) | ty::RawPtr(_) | ty::Ref(..) | ty::Str @@ -134,7 +133,7 @@ pub fn compute_dropck_outlives_inner<'tcx>( result.overflows.len(), ty_stack.len() ); - dtorck_constraint_for_ty_inner(tcx, DUMMY_SP, for_ty, depth, ty, &mut constraints)?; + dtorck_constraint_for_ty_inner(tcx, param_env, DUMMY_SP, depth, ty, &mut constraints)?; // "outlives" represent types/regions that may be touched // by a destructor. @@ -186,16 +185,15 @@ pub fn compute_dropck_outlives_inner<'tcx>( /// Returns a set of constraints that needs to be satisfied in /// order for `ty` to be valid for destruction. +#[instrument(level = "debug", skip(tcx, param_env, span, constraints))] pub fn dtorck_constraint_for_ty_inner<'tcx>( tcx: TyCtxt<'tcx>, + param_env: ty::ParamEnv<'tcx>, span: Span, - for_ty: Ty<'tcx>, depth: usize, ty: Ty<'tcx>, constraints: &mut DropckConstraint<'tcx>, ) -> Result<(), NoSolution> { - debug!("dtorck_constraint_for_ty_inner({:?}, {:?}, {:?}, {:?})", span, for_ty, depth, ty); - if !tcx.recursion_limit().value_within_limit(depth) { constraints.overflows.push(ty); return Ok(()); @@ -218,21 +216,20 @@ pub fn dtorck_constraint_for_ty_inner<'tcx>( | ty::Ref(..) | ty::FnDef(..) | ty::FnPtr(_) - | ty::GeneratorWitness(..) - | ty::GeneratorWitnessMIR(..) => { + | ty::GeneratorWitness(..) => { // these types never have a destructor } ty::Array(ety, _) | ty::Slice(ety) => { // single-element containers, behave like their element rustc_data_structures::stack::ensure_sufficient_stack(|| { - dtorck_constraint_for_ty_inner(tcx, span, for_ty, depth + 1, *ety, constraints) + dtorck_constraint_for_ty_inner(tcx, param_env, span, depth + 1, *ety, constraints) })?; } ty::Tuple(tys) => rustc_data_structures::stack::ensure_sufficient_stack(|| { for ty in tys.iter() { - dtorck_constraint_for_ty_inner(tcx, span, for_ty, depth + 1, ty, constraints)?; + dtorck_constraint_for_ty_inner(tcx, param_env, span, depth + 1, ty, constraints)?; } Ok::<_, NoSolution>(()) })?, @@ -251,7 +248,14 @@ pub fn dtorck_constraint_for_ty_inner<'tcx>( rustc_data_structures::stack::ensure_sufficient_stack(|| { for ty in args.as_closure().upvar_tys() { - dtorck_constraint_for_ty_inner(tcx, span, for_ty, depth + 1, ty, constraints)?; + dtorck_constraint_for_ty_inner( + tcx, + param_env, + span, + depth + 1, + ty, + constraints, + )?; } Ok::<_, NoSolution>(()) })? @@ -280,8 +284,8 @@ pub fn dtorck_constraint_for_ty_inner<'tcx>( // only take place through references with lifetimes // derived from lifetimes attached to the upvars and resume // argument, and we *do* incorporate those here. - - if !args.as_generator().is_valid() { + let args = args.as_generator(); + if !args.is_valid() { // By the time this code runs, all type variables ought to // be fully resolved. tcx.sess.delay_span_bug( @@ -291,10 +295,13 @@ pub fn dtorck_constraint_for_ty_inner<'tcx>( return Err(NoSolution); } - constraints - .outlives - .extend(args.as_generator().upvar_tys().iter().map(ty::GenericArg::from)); - constraints.outlives.push(args.as_generator().resume_ty().into()); + // While we conservatively assume that all coroutines require drop + // to avoid query cycles during MIR building, we can check the actual + // witness during borrowck to avoid unnecessary liveness constraints. + if args.witness().needs_drop(tcx, tcx.erase_regions(param_env)) { + constraints.outlives.extend(args.upvar_tys().iter().map(ty::GenericArg::from)); + constraints.outlives.push(args.resume_ty().into()); + } } ty::Adt(def, args) => { diff --git a/compiler/rustc_trait_selection/src/traits/query/normalize.rs b/compiler/rustc_trait_selection/src/traits/query/normalize.rs index 87beaddc6..f785211c5 100644 --- a/compiler/rustc_trait_selection/src/traits/query/normalize.rs +++ b/compiler/rustc_trait_selection/src/traits/query/normalize.rs @@ -358,7 +358,7 @@ impl<'cx, 'tcx> FallibleTypeFolder<TyCtxt<'tcx>> for QueryNormalizer<'cx, 'tcx> self.infcx, &mut self.universes, constant, - |constant| constant.eval(self.infcx.tcx, self.param_env), + |constant| constant.normalize(self.infcx.tcx, self.param_env), )) } diff --git a/compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs b/compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs index 979498fb6..e415d7047 100644 --- a/compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs +++ b/compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs @@ -13,7 +13,7 @@ use rustc_span::def_id::CRATE_DEF_ID; use rustc_span::source_map::DUMMY_SP; use smallvec::{smallvec, SmallVec}; -#[derive(Copy, Clone, Debug, HashStable, TypeFoldable, TypeVisitable, Lift)] +#[derive(Copy, Clone, Debug, HashStable, TypeFoldable, TypeVisitable)] pub struct ImpliedOutlivesBounds<'tcx> { pub ty: Ty<'tcx>, } diff --git a/compiler/rustc_trait_selection/src/traits/query/type_op/outlives.rs b/compiler/rustc_trait_selection/src/traits/query/type_op/outlives.rs index 59f4a22ac..f2c1243f9 100644 --- a/compiler/rustc_trait_selection/src/traits/query/type_op/outlives.rs +++ b/compiler/rustc_trait_selection/src/traits/query/type_op/outlives.rs @@ -6,7 +6,7 @@ use crate::traits::ObligationCtxt; use rustc_middle::traits::query::{DropckOutlivesResult, NoSolution}; use rustc_middle::ty::{ParamEnvAnd, Ty, TyCtxt}; -#[derive(Copy, Clone, Debug, HashStable, TypeFoldable, TypeVisitable, Lift)] +#[derive(Copy, Clone, Debug, HashStable, TypeFoldable, TypeVisitable)] pub struct DropckOutlives<'tcx> { dropped_ty: Ty<'tcx>, } |