diff options
Diffstat (limited to 'compiler/rustc_middle/src/ty/mod.rs')
| -rw-r--r-- | compiler/rustc_middle/src/ty/mod.rs | 324 |
1 files changed, 240 insertions, 84 deletions
diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs index 02da02568..3f9871190 100644 --- a/compiler/rustc_middle/src/ty/mod.rs +++ b/compiler/rustc_middle/src/ty/mod.rs @@ -15,6 +15,7 @@ pub use self::AssocItemContainer::*; pub use self::BorrowKind::*; pub use self::IntVarValue::*; pub use self::Variance::*; +use crate::error::{OpaqueHiddenTypeMismatch, TypeMismatchReason}; use crate::metadata::ModChild; use crate::middle::privacy::AccessLevels; use crate::mir::{Body, GeneratorLayout}; @@ -40,6 +41,7 @@ use rustc_hir::Node; use rustc_index::vec::IndexVec; use rustc_macros::HashStable; use rustc_query_system::ich::StableHashingContext; +use rustc_serialize::{Decodable, Encodable}; use rustc_span::hygiene::MacroKind; use rustc_span::symbol::{kw, sym, Ident, Symbol}; use rustc_span::{ExpnId, Span}; @@ -49,10 +51,14 @@ pub use vtable::*; use std::fmt::Debug; use std::hash::{Hash, Hasher}; +use std::marker::PhantomData; +use std::mem; +use std::num::NonZeroUsize; use std::ops::ControlFlow; use std::{fmt, str}; pub use crate::ty::diagnostics::*; +pub use rustc_type_ir::DynKind::*; pub use rustc_type_ir::InferTy::*; pub use rustc_type_ir::RegionKind::*; pub use rustc_type_ir::TyKind::*; @@ -124,6 +130,7 @@ mod erase_regions; mod generics; mod impls_ty; mod instance; +mod layout_sanity_check; mod list; mod parameterized; mod rvalue_scopes; @@ -177,11 +184,6 @@ pub struct ResolverAstLowering { pub label_res_map: NodeMap<ast::NodeId>, /// Resolutions for lifetimes. pub lifetimes_res_map: NodeMap<LifetimeRes>, - /// Mapping from generics `def_id`s to TAIT generics `def_id`s. - /// For each captured lifetime (e.g., 'a), we create a new lifetime parameter that is a generic - /// defined on the TAIT, so we have type Foo<'a1> = ... and we establish a mapping in this - /// field from the original parameter 'a to the new parameter 'a1. - pub generics_def_id_map: Vec<FxHashMap<LocalDefId, LocalDefId>>, /// Lifetime parameters that lowering will have to introduce. pub extra_lifetime_params_map: NodeMap<Vec<(Ident, ast::NodeId, LifetimeRes)>>, @@ -262,13 +264,11 @@ impl fmt::Display for ImplPolarity { } #[derive(Clone, Debug, PartialEq, Eq, Copy, Hash, Encodable, Decodable, HashStable)] -pub enum Visibility { +pub enum Visibility<Id = LocalDefId> { /// Visible everywhere (including in other crates). Public, /// Visible only in the given crate-local module. - Restricted(DefId), - /// Not visible anywhere in the local crate. This is the visibility of private external items. - Invisible, + Restricted(Id), } #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, HashStable, TyEncodable, TyDecodable)] @@ -359,31 +359,45 @@ impl<'tcx> DefIdTree for TyCtxt<'tcx> { } } -impl Visibility { - /// Returns `true` if an item with this visibility is accessible from the given block. - pub fn is_accessible_from<T: DefIdTree>(self, module: DefId, tree: T) -> bool { - let restriction = match self { - // Public items are visible everywhere. - Visibility::Public => return true, - // Private items from other crates are visible nowhere. - Visibility::Invisible => return false, - // Restricted items are visible in an arbitrary local module. - Visibility::Restricted(other) if other.krate != module.krate => return false, - Visibility::Restricted(module) => module, - }; +impl<Id> Visibility<Id> { + pub fn is_public(self) -> bool { + matches!(self, Visibility::Public) + } + + pub fn map_id<OutId>(self, f: impl FnOnce(Id) -> OutId) -> Visibility<OutId> { + match self { + Visibility::Public => Visibility::Public, + Visibility::Restricted(id) => Visibility::Restricted(f(id)), + } + } +} - tree.is_descendant_of(module, restriction) +impl<Id: Into<DefId>> Visibility<Id> { + pub fn to_def_id(self) -> Visibility<DefId> { + self.map_id(Into::into) + } + + /// Returns `true` if an item with this visibility is accessible from the given module. + pub fn is_accessible_from(self, module: impl Into<DefId>, tree: impl DefIdTree) -> bool { + match self { + // Public items are visible everywhere. + Visibility::Public => true, + Visibility::Restricted(id) => tree.is_descendant_of(module.into(), id.into()), + } } /// Returns `true` if this visibility is at least as accessible as the given visibility - pub fn is_at_least<T: DefIdTree>(self, vis: Visibility, tree: T) -> bool { - let vis_restriction = match vis { - Visibility::Public => return self == Visibility::Public, - Visibility::Invisible => return true, - Visibility::Restricted(module) => module, - }; + pub fn is_at_least(self, vis: Visibility<impl Into<DefId>>, tree: impl DefIdTree) -> bool { + match vis { + Visibility::Public => self.is_public(), + Visibility::Restricted(id) => self.is_accessible_from(id, tree), + } + } +} - self.is_accessible_from(vis_restriction, tree) +impl Visibility<DefId> { + pub fn expect_local(self) -> Visibility { + self.map_id(|id| id.expect_local()) } // Returns `true` if this item is visible anywhere in the local crate. @@ -391,13 +405,8 @@ impl Visibility { match self { Visibility::Public => true, Visibility::Restricted(def_id) => def_id.is_local(), - Visibility::Invisible => false, } } - - pub fn is_public(self) -> bool { - matches!(self, Visibility::Public) - } } /// The crate variances map is computed during typeck and contains the @@ -468,15 +477,6 @@ pub(crate) struct TyS<'tcx> { outer_exclusive_binder: ty::DebruijnIndex, } -// `TyS` is used a lot. Make sure it doesn't unintentionally get bigger. -#[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))] -static_assert_size!(TyS<'_>, 40); - -// We are actually storing a stable hash cache next to the type, so let's -// also check the full size -#[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))] -static_assert_size!(WithStableHash<TyS<'_>>, 56); - /// Use this rather than `TyS`, whenever possible. #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, HashStable)] #[rustc_diagnostic_item = "Ty"] @@ -533,10 +533,6 @@ pub(crate) struct PredicateS<'tcx> { outer_exclusive_binder: ty::DebruijnIndex, } -// This type is used a lot. Make sure it doesn't unintentionally get bigger. -#[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))] -static_assert_size!(PredicateS<'_>, 56); - /// Use this rather than `PredicateS`, whenever possible. #[derive(Clone, Copy, PartialEq, Eq, Hash)] #[rustc_pass_by_value] @@ -593,6 +589,29 @@ impl<'tcx> Predicate<'tcx> { } self } + + /// Whether this projection can be soundly normalized. + /// + /// Wf predicates must not be normalized, as normalization + /// can remove required bounds which would cause us to + /// unsoundly accept some programs. See #91068. + #[inline] + pub fn allow_normalization(self) -> bool { + match self.kind().skip_binder() { + PredicateKind::WellFormed(_) => false, + PredicateKind::Trait(_) + | PredicateKind::RegionOutlives(_) + | PredicateKind::TypeOutlives(_) + | PredicateKind::Projection(_) + | PredicateKind::ObjectSafe(_) + | PredicateKind::ClosureKind(_, _, _) + | PredicateKind::Subtype(_) + | PredicateKind::Coerce(_) + | PredicateKind::ConstEvaluatable(_) + | PredicateKind::ConstEquate(_, _) + | PredicateKind::TypeWellFormedFromEnv(_) => true, + } + } } impl<'a, 'tcx> HashStable<StableHashingContext<'a>> for Predicate<'tcx> { @@ -617,7 +636,7 @@ impl rustc_errors::IntoDiagnosticArg for Predicate<'_> { } #[derive(Clone, Copy, PartialEq, Eq, Hash, TyEncodable, TyDecodable)] -#[derive(HashStable, TypeFoldable, TypeVisitable)] +#[derive(HashStable, TypeFoldable, TypeVisitable, Lift)] pub enum PredicateKind<'tcx> { /// Corresponds to `where Foo: Bar<A, B, C>`. `Foo` here would be /// the `Self` type of the trait reference and `A`, `B`, and `C` @@ -789,7 +808,7 @@ impl<'tcx> Predicate<'tcx> { } #[derive(Clone, Copy, PartialEq, Eq, Hash, TyEncodable, TyDecodable)] -#[derive(HashStable, TypeFoldable, TypeVisitable)] +#[derive(HashStable, TypeFoldable, TypeVisitable, Lift)] pub struct TraitPredicate<'tcx> { pub trait_ref: TraitRef<'tcx>, @@ -869,7 +888,7 @@ impl<'tcx> PolyTraitPredicate<'tcx> { } #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug, TyEncodable, TyDecodable)] -#[derive(HashStable, TypeFoldable, TypeVisitable)] +#[derive(HashStable, TypeFoldable, TypeVisitable, Lift)] pub struct OutlivesPredicate<A, B>(pub A, pub B); // `A: B` pub type RegionOutlivesPredicate<'tcx> = OutlivesPredicate<ty::Region<'tcx>, ty::Region<'tcx>>; pub type TypeOutlivesPredicate<'tcx> = OutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>>; @@ -880,7 +899,7 @@ pub type PolyTypeOutlivesPredicate<'tcx> = ty::Binder<'tcx, TypeOutlivesPredicat /// whether the `a` type is the type that we should label as "expected" when /// presenting user diagnostics. #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug, TyEncodable, TyDecodable)] -#[derive(HashStable, TypeFoldable, TypeVisitable)] +#[derive(HashStable, TypeFoldable, TypeVisitable, Lift)] pub struct SubtypePredicate<'tcx> { pub a_is_expected: bool, pub a: Ty<'tcx>, @@ -890,49 +909,142 @@ pub type PolySubtypePredicate<'tcx> = ty::Binder<'tcx, SubtypePredicate<'tcx>>; /// Encodes that we have to coerce *from* the `a` type to the `b` type. #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug, TyEncodable, TyDecodable)] -#[derive(HashStable, TypeFoldable, TypeVisitable)] +#[derive(HashStable, TypeFoldable, TypeVisitable, Lift)] pub struct CoercePredicate<'tcx> { pub a: Ty<'tcx>, pub b: Ty<'tcx>, } pub type PolyCoercePredicate<'tcx> = ty::Binder<'tcx, CoercePredicate<'tcx>>; -#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, PartialOrd, Ord, TyEncodable, TyDecodable)] -#[derive(HashStable, TypeFoldable, TypeVisitable)] -pub enum Term<'tcx> { - Ty(Ty<'tcx>), - Const(Const<'tcx>), +#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)] +pub struct Term<'tcx> { + ptr: NonZeroUsize, + marker: PhantomData<(Ty<'tcx>, Const<'tcx>)>, +} + +impl Debug for Term<'_> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + let data = if let Some(ty) = self.ty() { + format!("Term::Ty({:?})", ty) + } else if let Some(ct) = self.ct() { + format!("Term::Ct({:?})", ct) + } else { + unreachable!() + }; + f.write_str(&data) + } } impl<'tcx> From<Ty<'tcx>> for Term<'tcx> { fn from(ty: Ty<'tcx>) -> Self { - Term::Ty(ty) + TermKind::Ty(ty).pack() } } impl<'tcx> From<Const<'tcx>> for Term<'tcx> { fn from(c: Const<'tcx>) -> Self { - Term::Const(c) + TermKind::Const(c).pack() + } +} + +impl<'a, 'tcx> HashStable<StableHashingContext<'a>> for Term<'tcx> { + fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) { + self.unpack().hash_stable(hcx, hasher); + } +} + +impl<'tcx> TypeFoldable<'tcx> for Term<'tcx> { + fn try_fold_with<F: FallibleTypeFolder<'tcx>>(self, folder: &mut F) -> Result<Self, F::Error> { + Ok(self.unpack().try_fold_with(folder)?.pack()) + } +} + +impl<'tcx> TypeVisitable<'tcx> for Term<'tcx> { + fn visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> { + self.unpack().visit_with(visitor) + } +} + +impl<'tcx, E: TyEncoder<I = TyCtxt<'tcx>>> Encodable<E> for Term<'tcx> { + fn encode(&self, e: &mut E) { + self.unpack().encode(e) + } +} + +impl<'tcx, D: TyDecoder<I = TyCtxt<'tcx>>> Decodable<D> for Term<'tcx> { + fn decode(d: &mut D) -> Self { + let res: TermKind<'tcx> = Decodable::decode(d); + res.pack() } } impl<'tcx> Term<'tcx> { + #[inline] + pub fn unpack(self) -> TermKind<'tcx> { + let ptr = self.ptr.get(); + // SAFETY: use of `Interned::new_unchecked` here is ok because these + // pointers were originally created from `Interned` types in `pack()`, + // and this is just going in the other direction. + unsafe { + match ptr & TAG_MASK { + TYPE_TAG => TermKind::Ty(Ty(Interned::new_unchecked( + &*((ptr & !TAG_MASK) as *const WithStableHash<ty::TyS<'tcx>>), + ))), + CONST_TAG => TermKind::Const(ty::Const(Interned::new_unchecked( + &*((ptr & !TAG_MASK) as *const ty::ConstS<'tcx>), + ))), + _ => core::intrinsics::unreachable(), + } + } + } + pub fn ty(&self) -> Option<Ty<'tcx>> { - if let Term::Ty(ty) = self { Some(*ty) } else { None } + if let TermKind::Ty(ty) = self.unpack() { Some(ty) } else { None } } pub fn ct(&self) -> Option<Const<'tcx>> { - if let Term::Const(c) = self { Some(*c) } else { None } + if let TermKind::Const(c) = self.unpack() { Some(c) } else { None } } pub fn into_arg(self) -> GenericArg<'tcx> { - match self { - Term::Ty(ty) => ty.into(), - Term::Const(c) => c.into(), + match self.unpack() { + TermKind::Ty(ty) => ty.into(), + TermKind::Const(c) => c.into(), } } } +const TAG_MASK: usize = 0b11; +const TYPE_TAG: usize = 0b00; +const CONST_TAG: usize = 0b01; + +#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, PartialOrd, Ord, TyEncodable, TyDecodable)] +#[derive(HashStable, TypeFoldable, TypeVisitable)] +pub enum TermKind<'tcx> { + Ty(Ty<'tcx>), + Const(Const<'tcx>), +} + +impl<'tcx> TermKind<'tcx> { + #[inline] + fn pack(self) -> Term<'tcx> { + let (tag, ptr) = match self { + TermKind::Ty(ty) => { + // Ensure we can use the tag bits. + assert_eq!(mem::align_of_val(&*ty.0.0) & TAG_MASK, 0); + (TYPE_TAG, ty.0.0 as *const WithStableHash<ty::TyS<'tcx>> as usize) + } + TermKind::Const(ct) => { + // Ensure we can use the tag bits. + assert_eq!(mem::align_of_val(&*ct.0.0) & TAG_MASK, 0); + (CONST_TAG, ct.0.0 as *const ty::ConstS<'tcx> as usize) + } + }; + + Term { ptr: unsafe { NonZeroUsize::new_unchecked(ptr | tag) }, marker: PhantomData } + } +} + /// This kind of predicate has no *direct* correspondent in the /// syntax, but it roughly corresponds to the syntactic forms: /// @@ -946,7 +1058,7 @@ impl<'tcx> Term<'tcx> { /// Form #2 eventually yields one of these `ProjectionPredicate` /// instances to normalize the LHS. #[derive(Copy, Clone, PartialEq, Eq, Hash, TyEncodable, TyDecodable)] -#[derive(HashStable, TypeFoldable, TypeVisitable)] +#[derive(HashStable, TypeFoldable, TypeVisitable, Lift)] pub struct ProjectionPredicate<'tcx> { pub projection_ty: ProjectionTy<'tcx>, pub term: Term<'tcx>, @@ -1002,6 +1114,12 @@ pub trait ToPredicate<'tcx> { fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx>; } +impl<'tcx> ToPredicate<'tcx> for Predicate<'tcx> { + fn to_predicate(self, _tcx: TyCtxt<'tcx>) -> Predicate<'tcx> { + self + } +} + impl<'tcx> ToPredicate<'tcx> for Binder<'tcx, PredicateKind<'tcx>> { #[inline(always)] fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> { @@ -1166,20 +1284,17 @@ pub struct OpaqueHiddenType<'tcx> { impl<'tcx> OpaqueHiddenType<'tcx> { pub fn report_mismatch(&self, other: &Self, tcx: TyCtxt<'tcx>) { // Found different concrete types for the opaque type. - let mut err = tcx.sess.struct_span_err( - other.span, - "concrete type differs from previous defining opaque type use", - ); - err.span_label(other.span, format!("expected `{}`, got `{}`", self.ty, other.ty)); - if self.span == other.span { - err.span_label( - self.span, - "this expression supplies two conflicting concrete types for the same opaque type", - ); + let sub_diag = if self.span == other.span { + TypeMismatchReason::ConflictType { span: self.span } } else { - err.span_note(self.span, "previous use here"); - } - err.emit(); + TypeMismatchReason::PreviousUse { span: self.span } + }; + tcx.sess.emit_err(OpaqueHiddenTypeMismatch { + self_ty: self.ty, + other_ty: other.ty, + other_span: other.span, + sub: sub_diag, + }); } } @@ -1411,7 +1526,7 @@ impl<'tcx> TypeFoldable<'tcx> for ParamEnv<'tcx> { Ok(ParamEnv::new( self.caller_bounds().try_fold_with(folder)?, self.reveal().try_fold_with(folder)?, - self.constness().try_fold_with(folder)?, + self.constness(), )) } } @@ -1419,8 +1534,7 @@ impl<'tcx> TypeFoldable<'tcx> for ParamEnv<'tcx> { impl<'tcx> TypeVisitable<'tcx> for ParamEnv<'tcx> { fn visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> { self.caller_bounds().visit_with(visitor)?; - self.reveal().visit_with(visitor)?; - self.constness().visit_with(visitor) + self.reveal().visit_with(visitor) } } @@ -1577,7 +1691,7 @@ impl<'tcx> PolyTraitRef<'tcx> { } #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, TypeFoldable, TypeVisitable)] -#[derive(HashStable)] +#[derive(HashStable, Lift)] pub struct ParamEnvAnd<'tcx, T> { pub param_env: ParamEnv<'tcx>, pub value: T, @@ -1779,7 +1893,7 @@ pub enum VariantDiscr { pub struct FieldDef { pub did: DefId, pub name: Symbol, - pub vis: Visibility, + pub vis: Visibility<DefId>, } impl PartialEq for FieldDef { @@ -2256,7 +2370,11 @@ impl<'tcx> TyCtxt<'tcx> { } pub fn get_attr(self, did: DefId, attr: Symbol) -> Option<&'tcx ast::Attribute> { - self.get_attrs(did, attr).next() + if cfg!(debug_assertions) && !rustc_feature::is_valid_for_get_attr(attr) { + bug!("get_attr: unexpected called with DefId `{:?}`, attr `{:?}`", did, attr); + } else { + self.get_attrs(did, attr).next() + } } /// Determines whether an item is annotated with an attribute. @@ -2358,6 +2476,25 @@ impl<'tcx> TyCtxt<'tcx> { (ident, scope) } + /// Returns `true` if the debuginfo for `span` should be collapsed to the outermost expansion + /// site. Only applies when `Span` is the result of macro expansion. + /// + /// - If the `collapse_debuginfo` feature is enabled then debuginfo is not collapsed by default + /// and only when a macro definition is annotated with `#[collapse_debuginfo]`. + /// - If `collapse_debuginfo` is not enabled, then debuginfo is collapsed by default. + /// + /// When `-Zdebug-macros` is provided then debuginfo will never be collapsed. + pub fn should_collapse_debuginfo(self, span: Span) -> bool { + !self.sess.opts.unstable_opts.debug_macros + && if self.features().collapse_debuginfo { + span.in_macro_expansion_with_collapse_debuginfo() + } else { + // Inlined spans should not be collapsed as that leads to all of the + // inlined code being attributed to the inline callsite. + span.from_expansion() && !span.is_inlined() + } + } + pub fn is_object_safe(self, key: DefId) -> bool { self.object_safety_violations(key).is_empty() } @@ -2372,6 +2509,14 @@ impl<'tcx> TyCtxt<'tcx> { pub fn is_const_default_method(self, def_id: DefId) -> bool { matches!(self.trait_of_item(def_id), Some(trait_id) if self.has_attr(trait_id, sym::const_trait)) } + + pub fn impl_trait_in_trait_parent(self, mut def_id: DefId) -> DefId { + while let def_kind = self.def_kind(def_id) && def_kind != DefKind::AssocFn { + debug_assert_eq!(def_kind, DefKind::ImplTraitPlaceholder); + def_id = self.parent(def_id); + } + def_id + } } /// Yields the parent function's `LocalDefId` if `def_id` is an `impl Trait` definition. @@ -2516,3 +2661,14 @@ pub struct DestructuredConst<'tcx> { pub variant: Option<VariantIdx>, pub fields: &'tcx [ty::Const<'tcx>], } + +// Some types are used a lot. Make sure they don't unintentionally get bigger. +#[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))] +mod size_asserts { + use super::*; + use rustc_data_structures::static_assert_size; + // These are in alphabetical order, which is easy to maintain. + static_assert_size!(PredicateS<'_>, 48); + static_assert_size!(TyS<'_>, 40); + static_assert_size!(WithStableHash<TyS<'_>>, 56); +} |