diff --git a/compiler/rustc_borrowck/src/def_use.rs b/compiler/rustc_borrowck/src/def_use.rs index 74e6ce37e971a..b775739fed2ae 100644 --- a/compiler/rustc_borrowck/src/def_use.rs +++ b/compiler/rustc_borrowck/src/def_use.rs @@ -55,7 +55,7 @@ pub fn categorize(context: PlaceContext) -> Option { // `PlaceMention` and `AscribeUserType` both evaluate the place, which must not // contain dangling references. PlaceContext::NonMutatingUse(NonMutatingUseContext::PlaceMention) | - PlaceContext::NonUse(NonUseContext::AscribeUserTy) | + PlaceContext::NonUse(NonUseContext::AscribeUserTy(_)) | PlaceContext::MutatingUse(MutatingUseContext::AddressOf) | PlaceContext::NonMutatingUse(NonMutatingUseContext::AddressOf) | diff --git a/compiler/rustc_borrowck/src/type_check/mod.rs b/compiler/rustc_borrowck/src/type_check/mod.rs index dcabeb792be3e..33b24b68f7cfc 100644 --- a/compiler/rustc_borrowck/src/type_check/mod.rs +++ b/compiler/rustc_borrowck/src/type_check/mod.rs @@ -777,7 +777,7 @@ impl<'a, 'b, 'tcx> TypeVerifier<'a, 'b, 'tcx> { Inspect | Copy | Move | PlaceMention | SharedBorrow | ShallowBorrow | UniqueBorrow | AddressOf | Projection, ) => ty::Covariant, - PlaceContext::NonUse(AscribeUserTy) => ty::Covariant, + PlaceContext::NonUse(AscribeUserTy(variance)) => variance, } } diff --git a/compiler/rustc_hir_analysis/src/check/check.rs b/compiler/rustc_hir_analysis/src/check/check.rs index c4d4e0d6d78bc..5187e63f8e3a1 100644 --- a/compiler/rustc_hir_analysis/src/check/check.rs +++ b/compiler/rustc_hir_analysis/src/check/check.rs @@ -31,6 +31,7 @@ use rustc_target::abi::FieldIdx; use rustc_target::spec::abi::Abi; use rustc_trait_selection::traits::error_reporting::on_unimplemented::OnUnimplementedDirective; use rustc_trait_selection::traits::error_reporting::TypeErrCtxtExt as _; +use rustc_trait_selection::traits::outlives_bounds::InferCtxtExt as _; use rustc_trait_selection::traits::{self, ObligationCtxt, TraitEngine, TraitEngineExt as _}; use std::ops::ControlFlow; @@ -222,7 +223,7 @@ fn check_opaque(tcx: TyCtxt<'_>, id: hir::ItemId) { if check_opaque_for_cycles(tcx, item.owner_id.def_id, substs, span, &origin).is_err() { return; } - check_opaque_meets_bounds(tcx, item.owner_id.def_id, substs, span, &origin); + check_opaque_meets_bounds(tcx, item.owner_id.def_id, span, &origin); } /// Checks that an opaque type does not use `Self` or `T::Foo` projections that would result @@ -391,7 +392,6 @@ pub(super) fn check_opaque_for_cycles<'tcx>( fn check_opaque_meets_bounds<'tcx>( tcx: TyCtxt<'tcx>, def_id: LocalDefId, - substs: SubstsRef<'tcx>, span: Span, origin: &hir::OpaqueTyOrigin, ) { @@ -406,6 +406,8 @@ fn check_opaque_meets_bounds<'tcx>( .with_opaque_type_inference(DefiningAnchor::Bind(defining_use_anchor)) .build(); let ocx = ObligationCtxt::new(&infcx); + + let substs = InternalSubsts::identity_for_item(tcx, def_id.to_def_id()); let opaque_ty = tcx.mk_opaque(def_id.to_def_id(), substs); // `ReErased` regions appear in the "parent_substs" of closures/generators. @@ -448,9 +450,18 @@ fn check_opaque_meets_bounds<'tcx>( match origin { // Checked when type checking the function containing them. hir::OpaqueTyOrigin::FnReturn(..) | hir::OpaqueTyOrigin::AsyncFn(..) => {} + // Nested opaque types occur only in associated types: + // ` type Opaque = impl Trait<&'static T, AssocTy = impl Nested>; ` + // They can only be referenced as ` as Trait<&'static T>>::AssocTy`. + // We don't have to check them here because their well-formedness follows from the WF of + // the projection input types in the defining- and use-sites. + hir::OpaqueTyOrigin::TyAlias + if tcx.def_kind(tcx.parent(def_id.to_def_id())) == DefKind::OpaqueTy => {} // Can have different predicates to their defining use hir::OpaqueTyOrigin::TyAlias => { - let outlives_env = OutlivesEnvironment::new(param_env); + let wf_tys = ocx.assumed_wf_types(param_env, span, def_id); + let implied_bounds = infcx.implied_bounds_tys(param_env, def_id, wf_tys); + let outlives_env = OutlivesEnvironment::with_bounds(param_env, implied_bounds); let _ = ocx.resolve_regions_and_report_errors(defining_use_anchor, &outlives_env); } } diff --git a/compiler/rustc_lint/src/nonstandard_style.rs b/compiler/rustc_lint/src/nonstandard_style.rs index 79253cbc8b43c..3fe600ce0468c 100644 --- a/compiler/rustc_lint/src/nonstandard_style.rs +++ b/compiler/rustc_lint/src/nonstandard_style.rs @@ -10,6 +10,7 @@ use rustc_hir::def::{DefKind, Res}; use rustc_hir::intravisit::FnKind; use rustc_hir::{GenericParamKind, PatKind}; use rustc_middle::ty; +use rustc_session::config::CrateType; use rustc_span::def_id::LocalDefId; use rustc_span::symbol::{sym, Ident}; use rustc_span::{BytePos, Span}; @@ -366,7 +367,11 @@ impl<'tcx> LateLintPass<'tcx> for NonSnakeCase { }) }; - if let Some(ident) = &crate_ident { + if let Some(ident) = &crate_ident + && cx.tcx.sess.crate_types().iter().all(|&crate_type| { + crate_type != CrateType::Executable + }) + { self.check_snake_case(cx, "crate", ident); } } diff --git a/compiler/rustc_middle/src/mir/visit.rs b/compiler/rustc_middle/src/mir/visit.rs index 6718605ed0bc4..4b7014e31090b 100644 --- a/compiler/rustc_middle/src/mir/visit.rs +++ b/compiler/rustc_middle/src/mir/visit.rs @@ -64,7 +64,7 @@ use crate::mir::*; use crate::ty::subst::SubstsRef; -use crate::ty::{CanonicalUserTypeAnnotation, Ty}; +use crate::ty::{self, CanonicalUserTypeAnnotation, Ty}; use rustc_span::Span; macro_rules! make_mir_visitor { @@ -782,12 +782,12 @@ macro_rules! make_mir_visitor { fn super_ascribe_user_ty(&mut self, place: & $($mutability)? Place<'tcx>, - _variance: $(& $mutability)? ty::Variance, + variance: $(& $mutability)? ty::Variance, user_ty: & $($mutability)? UserTypeProjection, location: Location) { self.visit_place( place, - PlaceContext::NonUse(NonUseContext::AscribeUserTy), + PlaceContext::NonUse(NonUseContext::AscribeUserTy($(* &$mutability *)? variance)), location ); self.visit_user_type_projection(user_ty); @@ -1320,7 +1320,7 @@ pub enum NonUseContext { /// Ending a storage live range. StorageDead, /// User type annotation assertions for NLL. - AscribeUserTy, + AscribeUserTy(ty::Variance), /// The data of a user variable, for debug info. VarDebugInfo, } diff --git a/compiler/rustc_mir_transform/src/ref_prop.rs b/compiler/rustc_mir_transform/src/ref_prop.rs index dafd2ae23a635..d1bc9ee91538e 100644 --- a/compiler/rustc_mir_transform/src/ref_prop.rs +++ b/compiler/rustc_mir_transform/src/ref_prop.rs @@ -85,7 +85,9 @@ fn propagate_ssa<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { let ssa = SsaLocals::new(body); let mut replacer = compute_replacement(tcx, body, &ssa); - debug!(?replacer.targets, ?replacer.allowed_replacements, ?replacer.storage_to_remove); + debug!(?replacer.targets); + debug!(?replacer.allowed_replacements); + debug!(?replacer.storage_to_remove); replacer.visit_body_preserves_cfg(body); @@ -190,8 +192,11 @@ fn compute_replacement<'tcx>( continue; } + // Whether the current local is subject to the uniqueness rule. + let needs_unique = ty.is_mutable_ptr(); + // If this a mutable reference that we cannot fully replace, mark it as unknown. - if ty.is_mutable_ptr() && !fully_replacable_locals.contains(local) { + if needs_unique && !fully_replacable_locals.contains(local) { debug!("not fully replaceable"); continue; } @@ -203,13 +208,14 @@ fn compute_replacement<'tcx>( // have been visited before. Rvalue::Use(Operand::Copy(place) | Operand::Move(place)) | Rvalue::CopyForDeref(place) => { - if let Some(rhs) = place.as_local() { + if let Some(rhs) = place.as_local() && ssa.is_ssa(rhs) { let target = targets[rhs]; - if matches!(target, Value::Pointer(..)) { + // Only see through immutable reference and pointers, as we do not know yet if + // mutable references are fully replaced. + if !needs_unique && matches!(target, Value::Pointer(..)) { targets[local] = target; - } else if ssa.is_ssa(rhs) { - let refmut = body.local_decls[rhs].ty.is_mutable_ptr(); - targets[local] = Value::Pointer(tcx.mk_place_deref(rhs.into()), refmut); + } else { + targets[local] = Value::Pointer(tcx.mk_place_deref(rhs.into()), needs_unique); } } } @@ -217,10 +223,10 @@ fn compute_replacement<'tcx>( let mut place = *place; // Try to see through `place` in order to collapse reborrow chains. if place.projection.first() == Some(&PlaceElem::Deref) - && let Value::Pointer(target, refmut) = targets[place.local] + && let Value::Pointer(target, inner_needs_unique) = targets[place.local] // Only see through immutable reference and pointers, as we do not know yet if // mutable references are fully replaced. - && !refmut + && !inner_needs_unique // Only collapse chain if the pointee is definitely live. && can_perform_opt(target, location) { @@ -228,7 +234,7 @@ fn compute_replacement<'tcx>( } assert_ne!(place.local, local); if is_constant_place(place) { - targets[local] = Value::Pointer(place, ty.is_mutable_ptr()); + targets[local] = Value::Pointer(place, needs_unique); } } // We do not know what to do, so keep as not-a-pointer. @@ -276,16 +282,35 @@ fn compute_replacement<'tcx>( return; } - if let Value::Pointer(target, refmut) = self.targets[place.local] - && place.projection.first() == Some(&PlaceElem::Deref) - { - let perform_opt = (self.can_perform_opt)(target, loc); - if perform_opt { - self.allowed_replacements.insert((target.local, loc)); - } else if refmut { - // This mutable reference is not fully replacable, so drop it. - self.targets[place.local] = Value::Unknown; + if place.projection.first() != Some(&PlaceElem::Deref) { + // This is not a dereference, nothing to do. + return; + } + + let mut place = place.as_ref(); + loop { + if let Value::Pointer(target, needs_unique) = self.targets[place.local] { + let perform_opt = (self.can_perform_opt)(target, loc); + debug!(?place, ?target, ?needs_unique, ?perform_opt); + + // This a reborrow chain, recursively allow the replacement. + // + // This also allows to detect cases where `target.local` is not replacable, + // and mark it as such. + if let &[PlaceElem::Deref] = &target.projection[..] { + assert!(perform_opt); + self.allowed_replacements.insert((target.local, loc)); + place.local = target.local; + continue; + } else if perform_opt { + self.allowed_replacements.insert((target.local, loc)); + } else if needs_unique { + // This mutable reference is not fully replacable, so drop it. + self.targets[place.local] = Value::Unknown; + } } + + break; } } } @@ -326,18 +351,23 @@ impl<'tcx> MutVisitor<'tcx> for Replacer<'tcx> { } fn visit_place(&mut self, place: &mut Place<'tcx>, ctxt: PlaceContext, loc: Location) { - if let Value::Pointer(target, _) = self.targets[place.local] - && place.projection.first() == Some(&PlaceElem::Deref) - { - let perform_opt = matches!(ctxt, PlaceContext::NonUse(_)) - || self.allowed_replacements.contains(&(target.local, loc)); - - if perform_opt { - *place = target.project_deeper(&place.projection[1..], self.tcx); - self.any_replacement = true; + if place.projection.first() != Some(&PlaceElem::Deref) { + return; + } + + loop { + if let Value::Pointer(target, _) = self.targets[place.local] { + let perform_opt = matches!(ctxt, PlaceContext::NonUse(_)) + || self.allowed_replacements.contains(&(target.local, loc)); + + if perform_opt { + *place = target.project_deeper(&place.projection[1..], self.tcx); + self.any_replacement = true; + continue; + } } - } else { - self.super_place(place, ctxt, loc); + + break; } } diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs index 2a8287d5554f8..d7509cbf10e33 100644 --- a/compiler/rustc_resolve/src/late.rs +++ b/compiler/rustc_resolve/src/late.rs @@ -1482,7 +1482,7 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> { if let Some(&(_, res)) = rib.bindings.get(&normalized_ident) { self.record_lifetime_res(lifetime.id, res, LifetimeElisionCandidate::Named); - if let LifetimeRes::Param { param, .. } = res { + if let LifetimeRes::Param { param, binder } = res { match self.lifetime_uses.entry(param) { Entry::Vacant(v) => { debug!("First use of {:?} at {:?}", res, ident.span); @@ -1496,10 +1496,16 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> { LifetimeRibKind::Item | LifetimeRibKind::AnonymousReportError | LifetimeRibKind::ElisionFailure => Some(LifetimeUseSet::Many), - // An anonymous lifetime is legal here, go ahead. - LifetimeRibKind::AnonymousCreateParameter { .. } => { - Some(LifetimeUseSet::One { use_span: ident.span, use_ctxt }) - } + // An anonymous lifetime is legal here, and bound to the right + // place, go ahead. + LifetimeRibKind::AnonymousCreateParameter { + binder: anon_binder, + .. + } => Some(if binder == anon_binder { + LifetimeUseSet::One { use_span: ident.span, use_ctxt } + } else { + LifetimeUseSet::Many + }), // Only report if eliding the lifetime would have the same // semantics. LifetimeRibKind::Elided(r) => Some(if res == r { diff --git a/compiler/rustc_ty_utils/src/implied_bounds.rs b/compiler/rustc_ty_utils/src/implied_bounds.rs index 56d6cc28bc83f..5ca5d14337cf0 100644 --- a/compiler/rustc_ty_utils/src/implied_bounds.rs +++ b/compiler/rustc_ty_utils/src/implied_bounds.rs @@ -31,6 +31,18 @@ fn assumed_wf_types(tcx: TyCtxt<'_>, def_id: DefId) -> &ty::List> { } } DefKind::AssocConst | DefKind::AssocTy => tcx.assumed_wf_types(tcx.parent(def_id)), + DefKind::OpaqueTy => match tcx.def_kind(tcx.parent(def_id)) { + DefKind::TyAlias => ty::List::empty(), + DefKind::AssocTy => tcx.assumed_wf_types(tcx.parent(def_id)), + // Nested opaque types only occur in associated types: + // ` type Opaque = impl Trait<&'static T, AssocTy = impl Nested>; ` + // assumed_wf_types should include those of `Opaque`, `Opaque` itself + // and `&'static T`. + DefKind::OpaqueTy => bug!("unimplemented implied bounds for neseted opaque types"), + def_kind @ _ => { + bug!("unimplemented implied bounds for opaque types with parent {def_kind:?}") + } + }, DefKind::Mod | DefKind::Struct | DefKind::Union @@ -51,7 +63,6 @@ fn assumed_wf_types(tcx: TyCtxt<'_>, def_id: DefId) -> &ty::List> { | DefKind::ForeignMod | DefKind::AnonConst | DefKind::InlineConst - | DefKind::OpaqueTy | DefKind::ImplTraitPlaceholder | DefKind::Field | DefKind::LifetimeParam diff --git a/compiler/rustc_type_ir/src/lib.rs b/compiler/rustc_type_ir/src/lib.rs index 7e5a4d1c73532..f6b44bdf27ef9 100644 --- a/compiler/rustc_type_ir/src/lib.rs +++ b/compiler/rustc_type_ir/src/lib.rs @@ -643,7 +643,7 @@ impl UnifyKey for FloatVid { } } -#[derive(Copy, Clone, PartialEq, Decodable, Encodable, Hash, HashStable_Generic)] +#[derive(Copy, Clone, PartialEq, Eq, Decodable, Encodable, Hash, HashStable_Generic)] #[rustc_pass_by_value] pub enum Variance { Covariant, // T <: T iff A <: B -- e.g., function return type diff --git a/src/tools/cargo b/src/tools/cargo index 26b73d15a68fb..13413c64ff88d 160000 --- a/src/tools/cargo +++ b/src/tools/cargo @@ -1 +1 @@ -Subproject commit 26b73d15a68fb94579f6d3590585ec0e9d81d3d5 +Subproject commit 13413c64ff88dd6c2824e9eb9374fc5f10895d28 diff --git a/tests/mir-opt/reference_prop.mut_raw_then_mut_shr.ReferencePropagation.diff b/tests/mir-opt/reference_prop.mut_raw_then_mut_shr.ReferencePropagation.diff new file mode 100644 index 0000000000000..af8ee2411d36d --- /dev/null +++ b/tests/mir-opt/reference_prop.mut_raw_then_mut_shr.ReferencePropagation.diff @@ -0,0 +1,74 @@ +- // MIR for `mut_raw_then_mut_shr` before ReferencePropagation ++ // MIR for `mut_raw_then_mut_shr` after ReferencePropagation + + fn mut_raw_then_mut_shr() -> (i32, i32) { + let mut _0: (i32, i32); // return place in scope 0 at $DIR/reference_prop.rs:+0:30: +0:40 + let mut _1: i32; // in scope 0 at $DIR/reference_prop.rs:+1:9: +1:14 + let mut _4: *mut i32; // in scope 0 at $DIR/reference_prop.rs:+3:16: +3:36 + let mut _5: &mut i32; // in scope 0 at $DIR/reference_prop.rs:+3:16: +3:26 + let _8: (); // in scope 0 at $DIR/reference_prop.rs:+7:5: +7:26 + let mut _9: i32; // in scope 0 at $DIR/reference_prop.rs:+8:6: +8:7 + let mut _10: i32; // in scope 0 at $DIR/reference_prop.rs:+8:9: +8:10 + scope 1 { + debug x => _1; // in scope 1 at $DIR/reference_prop.rs:+1:9: +1:14 + let _2: &mut i32; // in scope 1 at $DIR/reference_prop.rs:+2:9: +2:13 + scope 2 { + debug xref => _2; // in scope 2 at $DIR/reference_prop.rs:+2:9: +2:13 + let _3: *mut i32; // in scope 2 at $DIR/reference_prop.rs:+3:9: +3:13 + scope 3 { + debug xraw => _3; // in scope 3 at $DIR/reference_prop.rs:+3:9: +3:13 + let _6: &i32; // in scope 3 at $DIR/reference_prop.rs:+4:9: +4:13 + scope 4 { + debug xshr => _6; // in scope 4 at $DIR/reference_prop.rs:+4:9: +4:13 + let _7: i32; // in scope 4 at $DIR/reference_prop.rs:+6:9: +6:10 + scope 5 { + debug a => _7; // in scope 5 at $DIR/reference_prop.rs:+6:9: +6:10 + scope 6 { + } + } + } + } + } + } + + bb0: { + StorageLive(_1); // scope 0 at $DIR/reference_prop.rs:+1:9: +1:14 + _1 = const 2_i32; // scope 0 at $DIR/reference_prop.rs:+1:17: +1:18 +- StorageLive(_2); // scope 1 at $DIR/reference_prop.rs:+2:9: +2:13 + _2 = &mut _1; // scope 1 at $DIR/reference_prop.rs:+2:16: +2:22 + StorageLive(_3); // scope 2 at $DIR/reference_prop.rs:+3:9: +3:13 +- StorageLive(_4); // scope 2 at $DIR/reference_prop.rs:+3:16: +3:36 +- StorageLive(_5); // scope 2 at $DIR/reference_prop.rs:+3:16: +3:26 +- _5 = &mut (*_2); // scope 2 at $DIR/reference_prop.rs:+3:16: +3:26 +- _4 = &raw mut (*_5); // scope 2 at $DIR/reference_prop.rs:+3:16: +3:26 ++ _4 = &raw mut _1; // scope 2 at $DIR/reference_prop.rs:+3:16: +3:26 + _3 = _4; // scope 2 at $DIR/reference_prop.rs:+3:16: +3:36 +- StorageDead(_5); // scope 2 at $DIR/reference_prop.rs:+3:36: +3:37 +- StorageDead(_4); // scope 2 at $DIR/reference_prop.rs:+3:36: +3:37 + StorageLive(_6); // scope 3 at $DIR/reference_prop.rs:+4:9: +4:13 +- _6 = &(*_2); // scope 3 at $DIR/reference_prop.rs:+4:16: +4:22 ++ _6 = &_1; // scope 3 at $DIR/reference_prop.rs:+4:16: +4:22 + StorageLive(_7); // scope 4 at $DIR/reference_prop.rs:+6:9: +6:10 +- _7 = (*_6); // scope 4 at $DIR/reference_prop.rs:+6:13: +6:18 +- StorageLive(_8); // scope 5 at $DIR/reference_prop.rs:+7:5: +7:26 +- (*_3) = const 4_i32; // scope 6 at $DIR/reference_prop.rs:+7:14: +7:23 +- _8 = const (); // scope 6 at $DIR/reference_prop.rs:+7:5: +7:26 +- StorageDead(_8); // scope 5 at $DIR/reference_prop.rs:+7:25: +7:26 ++ _7 = _1; // scope 4 at $DIR/reference_prop.rs:+6:13: +6:18 ++ _1 = const 4_i32; // scope 6 at $DIR/reference_prop.rs:+7:14: +7:23 + StorageLive(_9); // scope 5 at $DIR/reference_prop.rs:+8:6: +8:7 + _9 = _7; // scope 5 at $DIR/reference_prop.rs:+8:6: +8:7 + StorageLive(_10); // scope 5 at $DIR/reference_prop.rs:+8:9: +8:10 + _10 = _1; // scope 5 at $DIR/reference_prop.rs:+8:9: +8:10 + _0 = (move _9, move _10); // scope 5 at $DIR/reference_prop.rs:+8:5: +8:11 + StorageDead(_10); // scope 5 at $DIR/reference_prop.rs:+8:10: +8:11 + StorageDead(_9); // scope 5 at $DIR/reference_prop.rs:+8:10: +8:11 + StorageDead(_7); // scope 4 at $DIR/reference_prop.rs:+9:1: +9:2 + StorageDead(_6); // scope 3 at $DIR/reference_prop.rs:+9:1: +9:2 + StorageDead(_3); // scope 2 at $DIR/reference_prop.rs:+9:1: +9:2 +- StorageDead(_2); // scope 1 at $DIR/reference_prop.rs:+9:1: +9:2 + StorageDead(_1); // scope 0 at $DIR/reference_prop.rs:+9:1: +9:2 + return; // scope 0 at $DIR/reference_prop.rs:+9:2: +9:2 + } + } + diff --git a/tests/mir-opt/reference_prop.read_through_raw.ReferencePropagation.diff b/tests/mir-opt/reference_prop.read_through_raw.ReferencePropagation.diff index a7d505c69066b..75c1f8f57ccae 100644 --- a/tests/mir-opt/reference_prop.read_through_raw.ReferencePropagation.diff +++ b/tests/mir-opt/reference_prop.read_through_raw.ReferencePropagation.diff @@ -9,15 +9,14 @@ let mut _5: *mut usize; // in scope 0 at $SRC_DIR/core/src/intrinsics/mir.rs:LL:COL bb0: { - _2 = &mut (*_1); // scope 0 at $DIR/reference_prop.rs:+10:13: +10:25 +- _2 = &mut (*_1); // scope 0 at $DIR/reference_prop.rs:+10:13: +10:25 - _3 = &mut (*_2); // scope 0 at $DIR/reference_prop.rs:+11:13: +11:26 - _4 = &raw mut (*_2); // scope 0 at $DIR/reference_prop.rs:+12:13: +12:30 - _5 = &raw mut (*_3); // scope 0 at $DIR/reference_prop.rs:+13:13: +13:30 - _0 = (*_4); // scope 0 at $DIR/reference_prop.rs:+15:13: +15:22 - _0 = (*_5); // scope 0 at $DIR/reference_prop.rs:+16:13: +16:22 -+ _3 = &mut (*_1); // scope 0 at $DIR/reference_prop.rs:+11:13: +11:26 -+ _0 = (*_2); // scope 0 at $DIR/reference_prop.rs:+15:13: +15:22 -+ _0 = (*_3); // scope 0 at $DIR/reference_prop.rs:+16:13: +16:22 ++ _0 = (*_1); // scope 0 at $DIR/reference_prop.rs:+15:13: +15:22 ++ _0 = (*_1); // scope 0 at $DIR/reference_prop.rs:+16:13: +16:22 return; // scope 0 at $DIR/reference_prop.rs:+17:13: +17:21 } } diff --git a/tests/mir-opt/reference_prop.rs b/tests/mir-opt/reference_prop.rs index e3e5d791464eb..93f8d1df8e85a 100644 --- a/tests/mir-opt/reference_prop.rs +++ b/tests/mir-opt/reference_prop.rs @@ -433,6 +433,29 @@ fn maybe_dead(m: bool) { ) } +fn mut_raw_then_mut_shr() -> (i32, i32) { + let mut x = 2; + let xref = &mut x; + let xraw = &mut *xref as *mut _; + let xshr = &*xref; + // Verify that we completely replace with `x` in both cases. + let a = *xshr; + unsafe { *xraw = 4; } + (a, x) +} + +fn unique_with_copies() { + let y = { + let mut a = 0; + let x = &raw mut a; + // `*y` is not replacable below, so we must not replace `*x`. + unsafe { opaque(*x) }; + x + }; + // But rewriting as `*x` is ok. + unsafe { opaque(*y) }; +} + fn main() { let mut x = 5_usize; let mut y = 7_usize; @@ -444,6 +467,8 @@ fn main() { multiple_storage(); dominate_storage(); maybe_dead(true); + mut_raw_then_mut_shr(); + unique_with_copies(); } // EMIT_MIR reference_prop.reference_propagation.ReferencePropagation.diff @@ -454,3 +479,5 @@ fn main() { // EMIT_MIR reference_prop.multiple_storage.ReferencePropagation.diff // EMIT_MIR reference_prop.dominate_storage.ReferencePropagation.diff // EMIT_MIR reference_prop.maybe_dead.ReferencePropagation.diff +// EMIT_MIR reference_prop.mut_raw_then_mut_shr.ReferencePropagation.diff +// EMIT_MIR reference_prop.unique_with_copies.ReferencePropagation.diff diff --git a/tests/mir-opt/reference_prop.unique_with_copies.ReferencePropagation.diff b/tests/mir-opt/reference_prop.unique_with_copies.ReferencePropagation.diff new file mode 100644 index 0000000000000..2cda2409e8093 --- /dev/null +++ b/tests/mir-opt/reference_prop.unique_with_copies.ReferencePropagation.diff @@ -0,0 +1,66 @@ +- // MIR for `unique_with_copies` before ReferencePropagation ++ // MIR for `unique_with_copies` after ReferencePropagation + + fn unique_with_copies() -> () { + let mut _0: (); // return place in scope 0 at $DIR/reference_prop.rs:+0:25: +0:25 + let _1: *mut i32; // in scope 0 at $DIR/reference_prop.rs:+1:9: +1:10 + let mut _2: i32; // in scope 0 at $DIR/reference_prop.rs:+2:13: +2:18 + let _4: (); // in scope 0 at $DIR/reference_prop.rs:+5:18: +5:28 + let mut _5: i32; // in scope 0 at $DIR/reference_prop.rs:+5:25: +5:27 + let _6: (); // in scope 0 at $DIR/reference_prop.rs:+9:14: +9:24 + let mut _7: i32; // in scope 0 at $DIR/reference_prop.rs:+9:21: +9:23 + scope 1 { + debug y => _1; // in scope 1 at $DIR/reference_prop.rs:+1:9: +1:10 + scope 5 { + } + } + scope 2 { + debug a => _2; // in scope 2 at $DIR/reference_prop.rs:+2:13: +2:18 + let _3: *mut i32; // in scope 2 at $DIR/reference_prop.rs:+3:13: +3:14 + scope 3 { + debug x => _3; // in scope 3 at $DIR/reference_prop.rs:+3:13: +3:14 + scope 4 { + } + } + } + + bb0: { + StorageLive(_1); // scope 0 at $DIR/reference_prop.rs:+1:9: +1:10 + StorageLive(_2); // scope 0 at $DIR/reference_prop.rs:+2:13: +2:18 + _2 = const 0_i32; // scope 0 at $DIR/reference_prop.rs:+2:21: +2:22 +- StorageLive(_3); // scope 2 at $DIR/reference_prop.rs:+3:13: +3:14 + _3 = &raw mut _2; // scope 2 at $DIR/reference_prop.rs:+3:17: +3:27 + StorageLive(_4); // scope 3 at $DIR/reference_prop.rs:+5:9: +5:30 + StorageLive(_5); // scope 4 at $DIR/reference_prop.rs:+5:25: +5:27 + _5 = (*_3); // scope 4 at $DIR/reference_prop.rs:+5:25: +5:27 + _4 = opaque::(move _5) -> bb1; // scope 4 at $DIR/reference_prop.rs:+5:18: +5:28 + // mir::Constant + // + span: $DIR/reference_prop.rs:452:18: 452:24 + // + literal: Const { ty: fn(i32) {opaque::}, val: Value() } + } + + bb1: { + StorageDead(_5); // scope 4 at $DIR/reference_prop.rs:+5:27: +5:28 + StorageDead(_4); // scope 3 at $DIR/reference_prop.rs:+5:30: +5:31 + _1 = _3; // scope 3 at $DIR/reference_prop.rs:+6:9: +6:10 +- StorageDead(_3); // scope 2 at $DIR/reference_prop.rs:+7:5: +7:6 + StorageDead(_2); // scope 0 at $DIR/reference_prop.rs:+7:5: +7:6 + StorageLive(_6); // scope 1 at $DIR/reference_prop.rs:+9:5: +9:26 + StorageLive(_7); // scope 5 at $DIR/reference_prop.rs:+9:21: +9:23 +- _7 = (*_1); // scope 5 at $DIR/reference_prop.rs:+9:21: +9:23 ++ _7 = (*_3); // scope 5 at $DIR/reference_prop.rs:+9:21: +9:23 + _6 = opaque::(move _7) -> bb2; // scope 5 at $DIR/reference_prop.rs:+9:14: +9:24 + // mir::Constant + // + span: $DIR/reference_prop.rs:456:14: 456:20 + // + literal: Const { ty: fn(i32) {opaque::}, val: Value() } + } + + bb2: { + StorageDead(_7); // scope 5 at $DIR/reference_prop.rs:+9:23: +9:24 + StorageDead(_6); // scope 1 at $DIR/reference_prop.rs:+9:26: +9:27 + _0 = const (); // scope 0 at $DIR/reference_prop.rs:+0:25: +10:2 + StorageDead(_1); // scope 0 at $DIR/reference_prop.rs:+10:1: +10:2 + return; // scope 0 at $DIR/reference_prop.rs:+10:2: +10:2 + } + } + diff --git a/tests/ui/associated-inherent-types/issue-109790.rs b/tests/ui/associated-inherent-types/issue-109790.rs index b2be19a28f442..88327f864237a 100644 --- a/tests/ui/associated-inherent-types/issue-109790.rs +++ b/tests/ui/associated-inherent-types/issue-109790.rs @@ -2,6 +2,7 @@ #![feature(inherent_associated_types)] #![allow(incomplete_features)] +#![deny(single_use_lifetimes)] struct Foo(T); diff --git a/tests/ui/lint/lint-non-snake-case-crate-2.stderr b/tests/ui/lint/lint-non-snake-case-crate-2.stderr deleted file mode 100644 index 4b42145bbed8b..0000000000000 --- a/tests/ui/lint/lint-non-snake-case-crate-2.stderr +++ /dev/null @@ -1,11 +0,0 @@ -error: crate `NonSnakeCase` should have a snake case name - | - = help: convert the identifier to snake case: `non_snake_case` -note: the lint level is defined here - --> $DIR/lint-non-snake-case-crate-2.rs:4:9 - | -LL | #![deny(non_snake_case)] - | ^^^^^^^^^^^^^^ - -error: aborting due to previous error - diff --git a/tests/ui/lint/lint-non-snake-case-crate-bin.rs b/tests/ui/lint/lint-non-snake-case-crate-bin.rs new file mode 100644 index 0000000000000..ef4ec35d2b927 --- /dev/null +++ b/tests/ui/lint/lint-non-snake-case-crate-bin.rs @@ -0,0 +1,6 @@ +// check-pass +#![crate_name = "NonSnakeCase"] + +#![deny(non_snake_case)] + +fn main() {} diff --git a/tests/ui/lint/lint-non-snake-case-crate-2.rs b/tests/ui/lint/lint-non-snake-case-crate-bin2.rs similarity index 54% rename from tests/ui/lint/lint-non-snake-case-crate-2.rs rename to tests/ui/lint/lint-non-snake-case-crate-bin2.rs index 1b763a9d868d9..fc80142aec83d 100644 --- a/tests/ui/lint/lint-non-snake-case-crate-2.rs +++ b/tests/ui/lint/lint-non-snake-case-crate-bin2.rs @@ -1,5 +1,5 @@ +// check-pass // compile-flags: --crate-name NonSnakeCase -// error-pattern: crate `NonSnakeCase` should have a snake case name #![deny(non_snake_case)] diff --git a/tests/ui/lint/lint-non-snake-case-crate-bin3.rs b/tests/ui/lint/lint-non-snake-case-crate-bin3.rs new file mode 100644 index 0000000000000..0327dbb07f7d5 --- /dev/null +++ b/tests/ui/lint/lint-non-snake-case-crate-bin3.rs @@ -0,0 +1,7 @@ +// check-pass +#![crate_type = "bin"] +#![crate_name = "NonSnakeCase"] + +#![deny(non_snake_case)] + +fn main() {} diff --git a/tests/ui/lint/lint-non-snake-case-crate-cdylib.rs b/tests/ui/lint/lint-non-snake-case-crate-cdylib.rs new file mode 100644 index 0000000000000..d2cd62fd68a8d --- /dev/null +++ b/tests/ui/lint/lint-non-snake-case-crate-cdylib.rs @@ -0,0 +1,6 @@ +#![crate_type = "cdylib"] +#![crate_name = "NonSnakeCase"] +//~^ ERROR crate `NonSnakeCase` should have a snake case name +#![deny(non_snake_case)] + +fn main() {} diff --git a/tests/ui/lint/lint-non-snake-case-crate-cdylib.stderr b/tests/ui/lint/lint-non-snake-case-crate-cdylib.stderr new file mode 100644 index 0000000000000..e98747f9aadc1 --- /dev/null +++ b/tests/ui/lint/lint-non-snake-case-crate-cdylib.stderr @@ -0,0 +1,14 @@ +error: crate `NonSnakeCase` should have a snake case name + --> $DIR/lint-non-snake-case-crate-cdylib.rs:2:18 + | +LL | #![crate_name = "NonSnakeCase"] + | ^^^^^^^^^^^^ help: convert the identifier to snake case: `non_snake_case` + | +note: the lint level is defined here + --> $DIR/lint-non-snake-case-crate-cdylib.rs:4:9 + | +LL | #![deny(non_snake_case)] + | ^^^^^^^^^^^^^^ + +error: aborting due to previous error + diff --git a/tests/ui/lint/lint-non-snake-case-crate-dylib.rs b/tests/ui/lint/lint-non-snake-case-crate-dylib.rs new file mode 100644 index 0000000000000..1ab974c54f6e3 --- /dev/null +++ b/tests/ui/lint/lint-non-snake-case-crate-dylib.rs @@ -0,0 +1,6 @@ +#![crate_type = "dylib"] +#![crate_name = "NonSnakeCase"] +//~^ ERROR crate `NonSnakeCase` should have a snake case name +#![deny(non_snake_case)] + +fn main() {} diff --git a/tests/ui/lint/lint-non-snake-case-crate-dylib.stderr b/tests/ui/lint/lint-non-snake-case-crate-dylib.stderr new file mode 100644 index 0000000000000..162373819aed9 --- /dev/null +++ b/tests/ui/lint/lint-non-snake-case-crate-dylib.stderr @@ -0,0 +1,14 @@ +error: crate `NonSnakeCase` should have a snake case name + --> $DIR/lint-non-snake-case-crate-dylib.rs:2:18 + | +LL | #![crate_name = "NonSnakeCase"] + | ^^^^^^^^^^^^ help: convert the identifier to snake case: `non_snake_case` + | +note: the lint level is defined here + --> $DIR/lint-non-snake-case-crate-dylib.rs:4:9 + | +LL | #![deny(non_snake_case)] + | ^^^^^^^^^^^^^^ + +error: aborting due to previous error + diff --git a/tests/ui/lint/lint-non-snake-case-crate.rs b/tests/ui/lint/lint-non-snake-case-crate-lib.rs similarity index 85% rename from tests/ui/lint/lint-non-snake-case-crate.rs rename to tests/ui/lint/lint-non-snake-case-crate-lib.rs index e4e84261a4ee9..79e020f07ba2a 100644 --- a/tests/ui/lint/lint-non-snake-case-crate.rs +++ b/tests/ui/lint/lint-non-snake-case-crate-lib.rs @@ -1,3 +1,4 @@ +#![crate_type = "lib"] #![crate_name = "NonSnakeCase"] //~^ ERROR crate `NonSnakeCase` should have a snake case name #![deny(non_snake_case)] diff --git a/tests/ui/lint/lint-non-snake-case-crate.stderr b/tests/ui/lint/lint-non-snake-case-crate-lib.stderr similarity index 77% rename from tests/ui/lint/lint-non-snake-case-crate.stderr rename to tests/ui/lint/lint-non-snake-case-crate-lib.stderr index da6b89c1e0499..4030925b16e4a 100644 --- a/tests/ui/lint/lint-non-snake-case-crate.stderr +++ b/tests/ui/lint/lint-non-snake-case-crate-lib.stderr @@ -1,11 +1,11 @@ error: crate `NonSnakeCase` should have a snake case name - --> $DIR/lint-non-snake-case-crate.rs:1:18 + --> $DIR/lint-non-snake-case-crate-lib.rs:2:18 | LL | #![crate_name = "NonSnakeCase"] | ^^^^^^^^^^^^ help: convert the identifier to snake case: `non_snake_case` | note: the lint level is defined here - --> $DIR/lint-non-snake-case-crate.rs:3:9 + --> $DIR/lint-non-snake-case-crate-lib.rs:4:9 | LL | #![deny(non_snake_case)] | ^^^^^^^^^^^^^^ diff --git a/tests/ui/lint/lint-non-snake-case-crate-proc-macro.rs b/tests/ui/lint/lint-non-snake-case-crate-proc-macro.rs new file mode 100644 index 0000000000000..949abe5573c79 --- /dev/null +++ b/tests/ui/lint/lint-non-snake-case-crate-proc-macro.rs @@ -0,0 +1,6 @@ +#![crate_type = "proc-macro"] +#![crate_name = "NonSnakeCase"] +//~^ ERROR crate `NonSnakeCase` should have a snake case name +#![deny(non_snake_case)] + +fn main() {} diff --git a/tests/ui/lint/lint-non-snake-case-crate-proc-macro.stderr b/tests/ui/lint/lint-non-snake-case-crate-proc-macro.stderr new file mode 100644 index 0000000000000..4848c4abf8207 --- /dev/null +++ b/tests/ui/lint/lint-non-snake-case-crate-proc-macro.stderr @@ -0,0 +1,14 @@ +error: crate `NonSnakeCase` should have a snake case name + --> $DIR/lint-non-snake-case-crate-proc-macro.rs:2:18 + | +LL | #![crate_name = "NonSnakeCase"] + | ^^^^^^^^^^^^ help: convert the identifier to snake case: `non_snake_case` + | +note: the lint level is defined here + --> $DIR/lint-non-snake-case-crate-proc-macro.rs:4:9 + | +LL | #![deny(non_snake_case)] + | ^^^^^^^^^^^^^^ + +error: aborting due to previous error + diff --git a/tests/ui/lint/lint-non-snake-case-crate-rlib.rs b/tests/ui/lint/lint-non-snake-case-crate-rlib.rs new file mode 100644 index 0000000000000..1d5334d81f303 --- /dev/null +++ b/tests/ui/lint/lint-non-snake-case-crate-rlib.rs @@ -0,0 +1,6 @@ +#![crate_type = "rlib"] +#![crate_name = "NonSnakeCase"] +//~^ ERROR crate `NonSnakeCase` should have a snake case name +#![deny(non_snake_case)] + +fn main() {} diff --git a/tests/ui/lint/lint-non-snake-case-crate-rlib.stderr b/tests/ui/lint/lint-non-snake-case-crate-rlib.stderr new file mode 100644 index 0000000000000..4d47c13f7d6d8 --- /dev/null +++ b/tests/ui/lint/lint-non-snake-case-crate-rlib.stderr @@ -0,0 +1,14 @@ +error: crate `NonSnakeCase` should have a snake case name + --> $DIR/lint-non-snake-case-crate-rlib.rs:2:18 + | +LL | #![crate_name = "NonSnakeCase"] + | ^^^^^^^^^^^^ help: convert the identifier to snake case: `non_snake_case` + | +note: the lint level is defined here + --> $DIR/lint-non-snake-case-crate-rlib.rs:4:9 + | +LL | #![deny(non_snake_case)] + | ^^^^^^^^^^^^^^ + +error: aborting due to previous error + diff --git a/tests/ui/lint/lint-non-snake-case-crate-staticlib.rs b/tests/ui/lint/lint-non-snake-case-crate-staticlib.rs new file mode 100644 index 0000000000000..d28fc9118aca8 --- /dev/null +++ b/tests/ui/lint/lint-non-snake-case-crate-staticlib.rs @@ -0,0 +1,6 @@ +#![crate_type = "staticlib"] +#![crate_name = "NonSnakeCase"] +//~^ ERROR crate `NonSnakeCase` should have a snake case name +#![deny(non_snake_case)] + +fn main() {} diff --git a/tests/ui/lint/lint-non-snake-case-crate-staticlib.stderr b/tests/ui/lint/lint-non-snake-case-crate-staticlib.stderr new file mode 100644 index 0000000000000..adc4b77d8beaa --- /dev/null +++ b/tests/ui/lint/lint-non-snake-case-crate-staticlib.stderr @@ -0,0 +1,14 @@ +error: crate `NonSnakeCase` should have a snake case name + --> $DIR/lint-non-snake-case-crate-staticlib.rs:2:18 + | +LL | #![crate_name = "NonSnakeCase"] + | ^^^^^^^^^^^^ help: convert the identifier to snake case: `non_snake_case` + | +note: the lint level is defined here + --> $DIR/lint-non-snake-case-crate-staticlib.rs:4:9 + | +LL | #![deny(non_snake_case)] + | ^^^^^^^^^^^^^^ + +error: aborting due to previous error + diff --git a/tests/ui/type-alias-impl-trait/wf-in-associated-type.fail.stderr b/tests/ui/type-alias-impl-trait/wf-in-associated-type.fail.stderr new file mode 100644 index 0000000000000..9e96323ab54bb --- /dev/null +++ b/tests/ui/type-alias-impl-trait/wf-in-associated-type.fail.stderr @@ -0,0 +1,25 @@ +error[E0309]: the parameter type `T` may not live long enough + --> $DIR/wf-in-associated-type.rs:36:23 + | +LL | type Opaque = impl Sized + 'a; + | ^^^^^^^^^^^^^^^ ...so that the type `&'a T` will meet its required lifetime bounds + | +help: consider adding an explicit lifetime bound... + | +LL | impl<'a, T: 'a> Trait<'a, T> for () { + | ++++ + +error[E0309]: the parameter type `T` may not live long enough + --> $DIR/wf-in-associated-type.rs:36:23 + | +LL | type Opaque = impl Sized + 'a; + | ^^^^^^^^^^^^^^^ ...so that the reference type `&'a T` does not outlive the data it points at + | +help: consider adding an explicit lifetime bound... + | +LL | impl<'a, T: 'a> Trait<'a, T> for () { + | ++++ + +error: aborting due to 2 previous errors + +For more information about this error, try `rustc --explain E0309`. diff --git a/tests/ui/type-alias-impl-trait/wf-in-associated-type.rs b/tests/ui/type-alias-impl-trait/wf-in-associated-type.rs new file mode 100644 index 0000000000000..31fbef9f78f83 --- /dev/null +++ b/tests/ui/type-alias-impl-trait/wf-in-associated-type.rs @@ -0,0 +1,45 @@ +// WF check for impl Trait in associated type position. +// +// revisions: pass fail +// [pass] check-pass +// [fail] check-fail + +#![feature(impl_trait_in_assoc_type)] + +// The hidden type here (`&'a T`) requires proving `T: 'a`. +// We know it holds because of implied bounds from the impl header. +#[cfg(pass)] +mod pass { + trait Trait { + type Opaque1; + fn constrain_opaque1(req: Req) -> Self::Opaque1; + } + + impl<'a, T> Trait<&'a T> for () { + type Opaque1 = impl IntoIterator; + fn constrain_opaque1(req: &'a T) -> Self::Opaque1 { + [req] + } + } +} + +// The hidden type here (`&'a T`) requires proving `T: 'a`, +// but that is not known to hold in the impl. +#[cfg(fail)] +mod fail { + trait Trait<'a, T> { + type Opaque; + fn constrain_opaque(req: &'a T) -> Self::Opaque; + } + + impl<'a, T> Trait<'a, T> for () { + type Opaque = impl Sized + 'a; + //[fail]~^ ERROR the parameter type `T` may not live long enough + //[fail]~| ERROR the parameter type `T` may not live long enough + fn constrain_opaque(req: &'a T) -> Self::Opaque { + req + } + } +} + +fn main() {} diff --git a/tests/ui/type-alias-impl-trait/wf-nested.fail.stderr b/tests/ui/type-alias-impl-trait/wf-nested.fail.stderr new file mode 100644 index 0000000000000..753a46e882eda --- /dev/null +++ b/tests/ui/type-alias-impl-trait/wf-nested.fail.stderr @@ -0,0 +1,19 @@ +error[E0310]: the parameter type `T` may not live long enough + --> $DIR/wf-nested.rs:55:27 + | +LL | type InnerOpaque = impl Sized; + | ^^^^^^^^^^ ...so that the type `T` will meet its required lifetime bounds... + | +note: ...that is required by this bound + --> $DIR/wf-nested.rs:12:20 + | +LL | struct IsStatic(T); + | ^^^^^^^ +help: consider adding an explicit lifetime bound... + | +LL | type InnerOpaque = impl Sized; + | +++++++++ + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0310`. diff --git a/tests/ui/type-alias-impl-trait/wf-nested.pass_sound.stderr b/tests/ui/type-alias-impl-trait/wf-nested.pass_sound.stderr new file mode 100644 index 0000000000000..9ab6685a7f73f --- /dev/null +++ b/tests/ui/type-alias-impl-trait/wf-nested.pass_sound.stderr @@ -0,0 +1,14 @@ +error[E0310]: the parameter type `T` may not live long enough + --> $DIR/wf-nested.rs:46:17 + | +LL | let _ = outer.get(); + | ^^^^^^^^^^^ ...so that the type `T` will meet its required lifetime bounds + | +help: consider adding an explicit lifetime bound... + | +LL | fn test() { + | +++++++++ + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0310`. diff --git a/tests/ui/type-alias-impl-trait/wf-nested.rs b/tests/ui/type-alias-impl-trait/wf-nested.rs new file mode 100644 index 0000000000000..de38832948918 --- /dev/null +++ b/tests/ui/type-alias-impl-trait/wf-nested.rs @@ -0,0 +1,60 @@ +// Well-formedness of nested opaque types, i.e. `impl Sized` in +// `type Outer = impl Trait`. +// See the comments below. +// +// revisions: pass pass_sound fail +// [pass] check-pass +// [pass_sound] check-fail +// [fail] check-fail + +#![feature(type_alias_impl_trait)] + +struct IsStatic(T); + +trait Trait { + type Out; + + fn get(&self) -> Result { + Err(()) + } +} + +impl Trait<&'static T> for () { + type Out = IsStatic; +} + +// The hidden type for `impl Sized` is `IsStatic`, which requires `T: 'static`. +// We know it is well-formed because it can *only* be referenced as a projection: +// as Trait<&'static T>>::Out`. +// So any instantiation of the type already requires proving `T: 'static`. +#[cfg(pass)] +mod pass { + use super::*; + type OuterOpaque = impl Trait<&'static T, Out = impl Sized>; + fn define() -> OuterOpaque {} +} + +// Test the soundness of `pass` - We should require `T: 'static` at the use site. +#[cfg(pass_sound)] +mod pass_sound { + use super::*; + type OuterOpaque = impl Trait<&'static T, Out = impl Sized>; + fn define() -> OuterOpaque {} + + fn test() { + let outer = define::(); + let _ = outer.get(); //[pass_sound]~ ERROR `T` may not live long enough + } +} + +// Similar to `pass` but here `impl Sized` can be referenced directly as +// InnerOpaque, so we require an explicit bound `T: 'static`. +#[cfg(fail)] +mod fail { + use super::*; + type InnerOpaque = impl Sized; //[fail]~ ERROR `T` may not live long enough + type OuterOpaque = impl Trait<&'static T, Out = InnerOpaque>; + fn define() -> OuterOpaque {} +} + +fn main() {}