//! Defines how the compiler represents types internally. //! //! Two important entities in this module are: //! //! - [`rustc_middle::ty::Ty`], used to represent the semantics of a type. //! - [`rustc_middle::ty::TyCtxt`], the central data structure in the compiler. //! //! For more information, see ["The `ty` module: representing types"] in the rustc-dev-guide. //! //! ["The `ty` module: representing types"]: https://rustc-dev-guide.rust-lang.org/ty.html #![allow(rustc::usage_of_ty_tykind)] use std::assert_matches::assert_matches; use std::fmt::Debug; use std::hash::{Hash, Hasher}; use std::marker::PhantomData; use std::num::NonZero; use std::ptr::NonNull; use std::{fmt, str}; pub use adt::*; pub use assoc::*; pub use generic_args::{GenericArgKind, TermKind, *}; pub use generics::*; pub use intrinsic::IntrinsicDef; use rustc_abi::{Align, FieldIdx, Integer, IntegerType, ReprFlags, ReprOptions, VariantIdx}; use rustc_ast::expand::StrippedCfgItem; use rustc_ast::node_id::NodeMap; pub use rustc_ast_ir::{Movability, Mutability, try_visit}; use rustc_attr_data_structures::AttributeKind; use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap, FxIndexSet}; use rustc_data_structures::intern::Interned; use rustc_data_structures::stable_hasher::{HashStable, StableHasher}; use rustc_data_structures::steal::Steal; use rustc_errors::{Diag, ErrorGuaranteed}; use rustc_hir::LangItem; use rustc_hir::def::{CtorKind, CtorOf, DefKind, DocLinkResMap, LifetimeRes, Res}; use rustc_hir::def_id::{CrateNum, DefId, DefIdMap, LocalDefId, LocalDefIdMap}; use rustc_index::IndexVec; use rustc_macros::{ Decodable, Encodable, HashStable, TyDecodable, TyEncodable, TypeFoldable, TypeVisitable, extension, }; use rustc_query_system::ich::StableHashingContext; use rustc_serialize::{Decodable, Encodable}; use rustc_session::lint::LintBuffer; pub use rustc_session::lint::RegisteredTools; use rustc_span::hygiene::MacroKind; use rustc_span::{ExpnId, ExpnKind, Ident, Span, Symbol, kw, sym}; pub use rustc_type_ir::relate::VarianceDiagInfo; pub use rustc_type_ir::*; use tracing::{debug, instrument}; pub use vtable::*; use {rustc_ast as ast, rustc_attr_data_structures as attr, rustc_hir as hir}; pub use self::closure::{ BorrowKind, CAPTURE_STRUCT_LOCAL, CaptureInfo, CapturedPlace, ClosureTypeInfo, MinCaptureInformationMap, MinCaptureList, RootVariableMinCaptureList, UpvarCapture, UpvarId, UpvarPath, analyze_coroutine_closure_captures, is_ancestor_or_same_capture, place_to_string_for_capture, }; pub use self::consts::{ Const, ConstInt, ConstKind, Expr, ExprKind, ScalarInt, UnevaluatedConst, ValTree, ValTreeKind, Value, }; pub use self::context::{ CtxtInterners, CurrentGcx, DeducedParamAttrs, Feed, FreeRegionInfo, GlobalCtxt, Lift, TyCtxt, TyCtxtFeed, tls, }; pub use self::fold::*; pub use self::instance::{Instance, InstanceKind, ReifyReason, ShortInstance, UnusedGenericParams}; pub use self::list::{List, ListWithCachedTypeInfo}; pub use self::opaque_types::OpaqueTypeKey; pub use self::parameterized::ParameterizedOverTcx; pub use self::pattern::{Pattern, PatternKind}; pub use self::predicate::{ AliasTerm, Clause, ClauseKind, CoercePredicate, ExistentialPredicate, ExistentialPredicateStableCmpExt, ExistentialProjection, ExistentialTraitRef, HostEffectPredicate, NormalizesTo, OutlivesPredicate, PolyCoercePredicate, PolyExistentialPredicate, PolyExistentialProjection, PolyExistentialTraitRef, PolyProjectionPredicate, PolyRegionOutlivesPredicate, PolySubtypePredicate, PolyTraitPredicate, PolyTraitRef, PolyTypeOutlivesPredicate, Predicate, PredicateKind, ProjectionPredicate, RegionOutlivesPredicate, SubtypePredicate, TraitPredicate, TraitRef, TypeOutlivesPredicate, }; pub use self::region::{ BoundRegion, BoundRegionKind, EarlyParamRegion, LateParamRegion, LateParamRegionKind, Region, RegionKind, RegionVid, }; pub use self::rvalue_scopes::RvalueScopes; pub use self::sty::{ AliasTy, Article, Binder, BoundTy, BoundTyKind, BoundVariableKind, CanonicalPolyFnSig, CoroutineArgsExt, EarlyBinder, FnSig, InlineConstArgs, InlineConstArgsParts, ParamConst, ParamTy, PolyFnSig, TyKind, TypeAndMut, TypingMode, UpvarArgs, }; pub use self::trait_def::TraitDef; pub use self::typeck_results::{ CanonicalUserType, CanonicalUserTypeAnnotation, CanonicalUserTypeAnnotations, IsIdentity, Rust2024IncompatiblePatInfo, TypeckResults, UserType, UserTypeAnnotationIndex, UserTypeKind, }; pub use self::visit::*; use crate::error::{OpaqueHiddenTypeMismatch, TypeMismatchReason}; use crate::metadata::ModChild; use crate::middle::privacy::EffectiveVisibilities; use crate::mir::{Body, CoroutineLayout}; use crate::query::{IntoQueryParam, Providers}; use crate::ty; use crate::ty::codec::{TyDecoder, TyEncoder}; pub use crate::ty::diagnostics::*; use crate::ty::fast_reject::SimplifiedType; use crate::ty::util::Discr; pub mod abstract_const; pub mod adjustment; pub mod cast; pub mod codec; pub mod error; pub mod fast_reject; pub mod flags; pub mod inhabitedness; pub mod layout; pub mod normalize_erasing_regions; pub mod pattern; pub mod print; pub mod relate; pub mod significant_drop_order; pub mod trait_def; pub mod util; pub mod vtable; pub mod walk; mod adt; mod assoc; mod closure; mod consts; mod context; mod diagnostics; mod elaborate_impl; mod erase_regions; mod fold; mod generic_args; mod generics; mod impls_ty; mod instance; mod intrinsic; mod list; mod opaque_types; mod parameterized; mod predicate; mod region; mod return_position_impl_trait_in_trait; mod rvalue_scopes; mod structural_impls; #[allow(hidden_glob_reexports)] mod sty; mod typeck_results; mod visit; // Data types pub struct ResolverOutputs { pub global_ctxt: ResolverGlobalCtxt, pub ast_lowering: ResolverAstLowering, } #[derive(Debug)] pub struct ResolverGlobalCtxt { pub visibilities_for_hashing: Vec<(LocalDefId, Visibility)>, /// Item with a given `LocalDefId` was defined during macro expansion with ID `ExpnId`. pub expn_that_defined: FxHashMap, pub effective_visibilities: EffectiveVisibilities, pub extern_crate_map: FxHashMap, pub maybe_unused_trait_imports: FxIndexSet, pub module_children: LocalDefIdMap>, pub glob_map: FxHashMap>, pub main_def: Option, pub trait_impls: FxIndexMap>, /// A list of proc macro LocalDefIds, written out in the order in which /// they are declared in the static array generated by proc_macro_harness. pub proc_macros: Vec, /// Mapping from ident span to path span for paths that don't exist as written, but that /// exist under `std`. For example, wrote `str::from_utf8` instead of `std::str::from_utf8`. pub confused_type_with_std_module: FxIndexMap, pub doc_link_resolutions: FxIndexMap, pub doc_link_traits_in_scope: FxIndexMap>, pub all_macro_rules: FxHashSet, pub stripped_cfg_items: Steal>, } /// Resolutions that should only be used for lowering. /// This struct is meant to be consumed by lowering. #[derive(Debug)] pub struct ResolverAstLowering { pub legacy_const_generic_args: FxHashMap>>, /// Resolutions for nodes that have a single resolution. pub partial_res_map: NodeMap, /// Resolutions for import nodes, which have multiple resolutions in different namespaces. pub import_res_map: NodeMap>>>, /// Resolutions for labels (node IDs of their corresponding blocks or loops). pub label_res_map: NodeMap, /// Resolutions for lifetimes. pub lifetimes_res_map: NodeMap, /// Lifetime parameters that lowering will have to introduce. pub extra_lifetime_params_map: NodeMap>, pub next_node_id: ast::NodeId, pub node_id_to_def_id: NodeMap, pub trait_map: NodeMap>, /// List functions and methods for which lifetime elision was successful. pub lifetime_elision_allowed: FxHashSet, /// Lints that were emitted by the resolver and early lints. pub lint_buffer: Steal, /// Information about functions signatures for delegation items expansion pub delegation_fn_sigs: LocalDefIdMap, } #[derive(Debug)] pub struct DelegationFnSig { pub header: ast::FnHeader, pub param_count: usize, pub has_self: bool, pub c_variadic: bool, pub target_feature: bool, } #[derive(Clone, Copy, Debug)] pub struct MainDefinition { pub res: Res, pub is_import: bool, pub span: Span, } impl MainDefinition { pub fn opt_fn_def_id(self) -> Option { if let Res::Def(DefKind::Fn, def_id) = self.res { Some(def_id) } else { None } } } /// The "header" of an impl is everything outside the body: a Self type, a trait /// ref (in the case of a trait impl), and a set of predicates (from the /// bounds / where-clauses). #[derive(Clone, Debug, TypeFoldable, TypeVisitable)] pub struct ImplHeader<'tcx> { pub impl_def_id: DefId, pub impl_args: ty::GenericArgsRef<'tcx>, pub self_ty: Ty<'tcx>, pub trait_ref: Option>, pub predicates: Vec>, } #[derive(Copy, Clone, Debug, TyEncodable, TyDecodable, HashStable)] pub struct ImplTraitHeader<'tcx> { pub trait_ref: ty::EarlyBinder<'tcx, ty::TraitRef<'tcx>>, pub polarity: ImplPolarity, pub safety: hir::Safety, pub constness: hir::Constness, } #[derive(Copy, Clone, PartialEq, Eq, Debug, TypeFoldable, TypeVisitable)] pub enum ImplSubject<'tcx> { Trait(TraitRef<'tcx>), Inherent(Ty<'tcx>), } #[derive(Copy, Clone, PartialEq, Eq, Hash, TyEncodable, TyDecodable, HashStable, Debug)] #[derive(TypeFoldable, TypeVisitable)] pub enum Asyncness { Yes, No, } impl Asyncness { pub fn is_async(self) -> bool { matches!(self, Asyncness::Yes) } } #[derive(Clone, Debug, PartialEq, Eq, Copy, Hash, Encodable, Decodable, HashStable)] pub enum Visibility { /// Visible everywhere (including in other crates). Public, /// Visible only in the given crate-local module. Restricted(Id), } impl Visibility { pub fn to_string(self, def_id: LocalDefId, tcx: TyCtxt<'_>) -> String { match self { ty::Visibility::Restricted(restricted_id) => { if restricted_id.is_top_level_module() { "pub(crate)".to_string() } else if restricted_id == tcx.parent_module_from_def_id(def_id).to_local_def_id() { "pub(self)".to_string() } else { format!("pub({})", tcx.item_name(restricted_id.to_def_id())) } } ty::Visibility::Public => "pub".to_string(), } } } #[derive(Clone, Debug, PartialEq, Eq, Copy, Hash, TyEncodable, TyDecodable, HashStable)] #[derive(TypeFoldable, TypeVisitable)] pub struct ClosureSizeProfileData<'tcx> { /// Tuple containing the types of closure captures before the feature `capture_disjoint_fields` pub before_feature_tys: Ty<'tcx>, /// Tuple containing the types of closure captures after the feature `capture_disjoint_fields` pub after_feature_tys: Ty<'tcx>, } impl TyCtxt<'_> { #[inline] pub fn opt_parent(self, id: DefId) -> Option { self.def_key(id).parent.map(|index| DefId { index, ..id }) } #[inline] #[track_caller] pub fn parent(self, id: DefId) -> DefId { match self.opt_parent(id) { Some(id) => id, // not `unwrap_or_else` to avoid breaking caller tracking None => bug!("{id:?} doesn't have a parent"), } } #[inline] #[track_caller] pub fn opt_local_parent(self, id: LocalDefId) -> Option { self.opt_parent(id.to_def_id()).map(DefId::expect_local) } #[inline] #[track_caller] pub fn local_parent(self, id: impl Into) -> LocalDefId { self.parent(id.into().to_def_id()).expect_local() } pub fn is_descendant_of(self, mut descendant: DefId, ancestor: DefId) -> bool { if descendant.krate != ancestor.krate { return false; } while descendant != ancestor { match self.opt_parent(descendant) { Some(parent) => descendant = parent, None => return false, } } true } } impl Visibility { pub fn is_public(self) -> bool { matches!(self, Visibility::Public) } pub fn map_id(self, f: impl FnOnce(Id) -> OutId) -> Visibility { match self { Visibility::Public => Visibility::Public, Visibility::Restricted(id) => Visibility::Restricted(f(id)), } } } impl> Visibility { pub fn to_def_id(self) -> Visibility { 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, tcx: TyCtxt<'_>) -> bool { match self { // Public items are visible everywhere. Visibility::Public => true, Visibility::Restricted(id) => tcx.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(self, vis: Visibility>, tcx: TyCtxt<'_>) -> bool { match vis { Visibility::Public => self.is_public(), Visibility::Restricted(id) => self.is_accessible_from(id, tcx), } } } impl Visibility { 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. pub fn is_visible_locally(self) -> bool { match self { Visibility::Public => true, Visibility::Restricted(def_id) => def_id.is_local(), } } } /// The crate variances map is computed during typeck and contains the /// variance of every item in the local crate. You should not use it /// directly, because to do so will make your pass dependent on the /// HIR of every item in the local crate. Instead, use /// `tcx.variances_of()` to get the variance for a *particular* /// item. #[derive(HashStable, Debug)] pub struct CrateVariancesMap<'tcx> { /// For each item with generics, maps to a vector of the variance /// of its generics. If an item has no generics, it will have no /// entry. pub variances: DefIdMap<&'tcx [ty::Variance]>, } // Contains information needed to resolve types and (in the future) look up // the types of AST nodes. #[derive(Copy, Clone, PartialEq, Eq, Hash)] pub struct CReaderCacheKey { pub cnum: Option, pub pos: usize, } /// Use this rather than `TyKind`, whenever possible. #[derive(Copy, Clone, PartialEq, Eq, Hash, HashStable)] #[rustc_diagnostic_item = "Ty"] #[rustc_pass_by_value] pub struct Ty<'tcx>(Interned<'tcx, WithCachedTypeInfo>>); impl<'tcx> rustc_type_ir::inherent::IntoKind for Ty<'tcx> { type Kind = TyKind<'tcx>; fn kind(self) -> TyKind<'tcx> { *self.kind() } } impl<'tcx> rustc_type_ir::Flags for Ty<'tcx> { fn flags(&self) -> TypeFlags { self.0.flags } fn outer_exclusive_binder(&self) -> DebruijnIndex { self.0.outer_exclusive_binder } } impl EarlyParamRegion { /// Does this early bound region have a name? Early bound regions normally /// always have names except when using anonymous lifetimes (`'_`). pub fn has_name(&self) -> bool { self.name != kw::UnderscoreLifetime && self.name != kw::Empty } } /// The crate outlives map is computed during typeck and contains the /// outlives of every item in the local crate. You should not use it /// directly, because to do so will make your pass dependent on the /// HIR of every item in the local crate. Instead, use /// `tcx.inferred_outlives_of()` to get the outlives for a *particular* /// item. #[derive(HashStable, Debug)] pub struct CratePredicatesMap<'tcx> { /// For each struct with outlive bounds, maps to a vector of the /// predicate of its outlive bounds. If an item has no outlives /// bounds, it will have no entry. pub predicates: DefIdMap<&'tcx [(Clause<'tcx>, Span)]>, } #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)] pub struct Term<'tcx> { ptr: NonNull<()>, marker: PhantomData<(Ty<'tcx>, Const<'tcx>)>, } impl<'tcx> rustc_type_ir::inherent::Term> for Term<'tcx> {} impl<'tcx> rustc_type_ir::inherent::IntoKind for Term<'tcx> { type Kind = TermKind<'tcx>; fn kind(self) -> Self::Kind { self.unpack() } } unsafe impl<'tcx> rustc_data_structures::sync::DynSend for Term<'tcx> where &'tcx (Ty<'tcx>, Const<'tcx>): rustc_data_structures::sync::DynSend { } unsafe impl<'tcx> rustc_data_structures::sync::DynSync for Term<'tcx> where &'tcx (Ty<'tcx>, Const<'tcx>): rustc_data_structures::sync::DynSync { } unsafe impl<'tcx> Send for Term<'tcx> where &'tcx (Ty<'tcx>, Const<'tcx>): Send {} unsafe impl<'tcx> Sync for Term<'tcx> where &'tcx (Ty<'tcx>, Const<'tcx>): Sync {} impl Debug for Term<'_> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { match self.unpack() { TermKind::Ty(ty) => write!(f, "Term::Ty({ty:?})"), TermKind::Const(ct) => write!(f, "Term::Const({ct:?})"), } } } impl<'tcx> From> for Term<'tcx> { fn from(ty: Ty<'tcx>) -> Self { TermKind::Ty(ty).pack() } } impl<'tcx> From> for Term<'tcx> { fn from(c: Const<'tcx>) -> Self { TermKind::Const(c).pack() } } impl<'a, 'tcx> HashStable> for Term<'tcx> { fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) { self.unpack().hash_stable(hcx, hasher); } } impl<'tcx> TypeFoldable> for Term<'tcx> { fn try_fold_with>>( self, folder: &mut F, ) -> Result { match self.unpack() { ty::TermKind::Ty(ty) => ty.try_fold_with(folder).map(Into::into), ty::TermKind::Const(ct) => ct.try_fold_with(folder).map(Into::into), } } } impl<'tcx> TypeVisitable> for Term<'tcx> { fn visit_with>>(&self, visitor: &mut V) -> V::Result { match self.unpack() { ty::TermKind::Ty(ty) => ty.visit_with(visitor), ty::TermKind::Const(ct) => ct.visit_with(visitor), } } } impl<'tcx, E: TyEncoder<'tcx>> Encodable for Term<'tcx> { fn encode(&self, e: &mut E) { self.unpack().encode(e) } } impl<'tcx, D: TyDecoder<'tcx>> Decodable 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 = unsafe { self.ptr.map_addr(|addr| NonZero::new_unchecked(addr.get() & !TAG_MASK)) }; // 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 self.ptr.addr().get() & TAG_MASK { TYPE_TAG => TermKind::Ty(Ty(Interned::new_unchecked( ptr.cast::>>().as_ref(), ))), CONST_TAG => TermKind::Const(ty::Const(Interned::new_unchecked( ptr.cast::>>().as_ref(), ))), _ => core::intrinsics::unreachable(), } } } pub fn as_type(&self) -> Option> { if let TermKind::Ty(ty) = self.unpack() { Some(ty) } else { None } } pub fn expect_type(&self) -> Ty<'tcx> { self.as_type().expect("expected a type, but found a const") } pub fn as_const(&self) -> Option> { if let TermKind::Const(c) = self.unpack() { Some(c) } else { None } } pub fn expect_const(&self) -> Const<'tcx> { self.as_const().expect("expected a const, but found a type") } pub fn into_arg(self) -> GenericArg<'tcx> { match self.unpack() { TermKind::Ty(ty) => ty.into(), TermKind::Const(c) => c.into(), } } pub fn to_alias_term(self) -> Option> { match self.unpack() { TermKind::Ty(ty) => match *ty.kind() { ty::Alias(_kind, alias_ty) => Some(alias_ty.into()), _ => None, }, TermKind::Const(ct) => match ct.kind() { ConstKind::Unevaluated(uv) => Some(uv.into()), _ => None, }, } } pub fn is_infer(&self) -> bool { match self.unpack() { TermKind::Ty(ty) => ty.is_ty_var(), TermKind::Const(ct) => ct.is_ct_infer(), } } } const TAG_MASK: usize = 0b11; const TYPE_TAG: usize = 0b00; const CONST_TAG: usize = 0b01; #[extension(pub trait TermKindPackExt<'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!(align_of_val(&*ty.0.0) & TAG_MASK, 0); (TYPE_TAG, NonNull::from(ty.0.0).cast()) } TermKind::Const(ct) => { // Ensure we can use the tag bits. assert_eq!(align_of_val(&*ct.0.0) & TAG_MASK, 0); (CONST_TAG, NonNull::from(ct.0.0).cast()) } }; Term { ptr: ptr.map_addr(|addr| addr | tag), marker: PhantomData } } } #[derive(Copy, Clone, PartialEq, Eq, Debug)] pub enum ParamTerm { Ty(ParamTy), Const(ParamConst), } impl ParamTerm { pub fn index(self) -> usize { match self { ParamTerm::Ty(ty) => ty.index as usize, ParamTerm::Const(ct) => ct.index as usize, } } } #[derive(Copy, Clone, Eq, PartialEq, Debug)] pub enum TermVid { Ty(ty::TyVid), Const(ty::ConstVid), } impl From for TermVid { fn from(value: ty::TyVid) -> Self { TermVid::Ty(value) } } impl From for TermVid { fn from(value: ty::ConstVid) -> Self { TermVid::Const(value) } } /// Represents the bounds declared on a particular set of type /// parameters. Should eventually be generalized into a flag list of /// where-clauses. You can obtain an `InstantiatedPredicates` list from a /// `GenericPredicates` by using the `instantiate` method. Note that this method /// reflects an important semantic invariant of `InstantiatedPredicates`: while /// the `GenericPredicates` are expressed in terms of the bound type /// parameters of the impl/trait/whatever, an `InstantiatedPredicates` instance /// represented a set of bounds for some particular instantiation, /// meaning that the generic parameters have been instantiated with /// their values. /// /// Example: /// ```ignore (illustrative) /// struct Foo> { ... } /// ``` /// Here, the `GenericPredicates` for `Foo` would contain a list of bounds like /// `[[], [U:Bar]]`. Now if there were some particular reference /// like `Foo`, then the `InstantiatedPredicates` would be `[[], /// [usize:Bar]]`. #[derive(Clone, Debug, TypeFoldable, TypeVisitable)] pub struct InstantiatedPredicates<'tcx> { pub predicates: Vec>, pub spans: Vec, } impl<'tcx> InstantiatedPredicates<'tcx> { pub fn empty() -> InstantiatedPredicates<'tcx> { InstantiatedPredicates { predicates: vec![], spans: vec![] } } pub fn is_empty(&self) -> bool { self.predicates.is_empty() } pub fn iter(&self) -> <&Self as IntoIterator>::IntoIter { self.into_iter() } } impl<'tcx> IntoIterator for InstantiatedPredicates<'tcx> { type Item = (Clause<'tcx>, Span); type IntoIter = std::iter::Zip>, std::vec::IntoIter>; fn into_iter(self) -> Self::IntoIter { debug_assert_eq!(self.predicates.len(), self.spans.len()); std::iter::zip(self.predicates, self.spans) } } impl<'a, 'tcx> IntoIterator for &'a InstantiatedPredicates<'tcx> { type Item = (Clause<'tcx>, Span); type IntoIter = std::iter::Zip< std::iter::Copied>>, std::iter::Copied>, >; fn into_iter(self) -> Self::IntoIter { debug_assert_eq!(self.predicates.len(), self.spans.len()); std::iter::zip(self.predicates.iter().copied(), self.spans.iter().copied()) } } #[derive(Copy, Clone, Debug, TypeFoldable, TypeVisitable, HashStable, TyEncodable, TyDecodable)] pub struct OpaqueHiddenType<'tcx> { /// The span of this particular definition of the opaque type. So /// for example: /// /// ```ignore (incomplete snippet) /// type Foo = impl Baz; /// fn bar() -> Foo { /// // ^^^ This is the span we are looking for! /// } /// ``` /// /// In cases where the fn returns `(impl Trait, impl Trait)` or /// other such combinations, the result is currently /// over-approximated, but better than nothing. pub span: Span, /// The type variable that represents the value of the opaque type /// that we require. In other words, after we compile this function, /// we will be created a constraint like: /// ```ignore (pseudo-rust) /// Foo<'a, T> = ?C /// ``` /// where `?C` is the value of this type variable. =) It may /// naturally refer to the type and lifetime parameters in scope /// in this function, though ultimately it should only reference /// those that are arguments to `Foo` in the constraint above. (In /// other words, `?C` should not include `'b`, even though it's a /// lifetime parameter on `foo`.) pub ty: Ty<'tcx>, } impl<'tcx> OpaqueHiddenType<'tcx> { pub fn build_mismatch_error( &self, other: &Self, tcx: TyCtxt<'tcx>, ) -> Result, ErrorGuaranteed> { (self.ty, other.ty).error_reported()?; // Found different concrete types for the opaque type. let sub_diag = if self.span == other.span { TypeMismatchReason::ConflictType { span: self.span } } else { TypeMismatchReason::PreviousUse { span: self.span } }; Ok(tcx.dcx().create_err(OpaqueHiddenTypeMismatch { self_ty: self.ty, other_ty: other.ty, other_span: other.span, sub: sub_diag, })) } #[instrument(level = "debug", skip(tcx), ret)] pub fn remap_generic_params_to_declaration_params( self, opaque_type_key: OpaqueTypeKey<'tcx>, tcx: TyCtxt<'tcx>, // typeck errors have subpar spans for opaque types, so delay error reporting until borrowck. ignore_errors: bool, ) -> Self { let OpaqueTypeKey { def_id, args } = opaque_type_key; // Use args to build up a reverse map from regions to their // identity mappings. This is necessary because of `impl // Trait` lifetimes are computed by replacing existing // lifetimes with 'static and remapping only those used in the // `impl Trait` return type, resulting in the parameters // shifting. let id_args = GenericArgs::identity_for_item(tcx, def_id); debug!(?id_args); // This zip may have several times the same lifetime in `args` paired with a different // lifetime from `id_args`. Simply `collect`ing the iterator is the correct behaviour: // it will pick the last one, which is the one we introduced in the impl-trait desugaring. let map = args.iter().zip(id_args).collect(); debug!("map = {:#?}", map); // Convert the type from the function into a type valid outside // the function, by replacing invalid regions with 'static, // after producing an error for each of them. self.fold_with(&mut opaque_types::ReverseMapper::new(tcx, map, self.span, ignore_errors)) } } /// The "placeholder index" fully defines a placeholder region, type, or const. Placeholders are /// identified by both a universe, as well as a name residing within that universe. Distinct bound /// regions/types/consts within the same universe simply have an unknown relationship to one /// another. #[derive(Copy, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)] #[derive(HashStable, TyEncodable, TyDecodable)] pub struct Placeholder { pub universe: UniverseIndex, pub bound: T, } impl Placeholder { pub fn find_const_ty_from_env<'tcx>(self, env: ParamEnv<'tcx>) -> Ty<'tcx> { let mut candidates = env.caller_bounds().iter().filter_map(|clause| { // `ConstArgHasType` are never desugared to be higher ranked. match clause.kind().skip_binder() { ty::ClauseKind::ConstArgHasType(placeholder_ct, ty) => { assert!(!(placeholder_ct, ty).has_escaping_bound_vars()); match placeholder_ct.kind() { ty::ConstKind::Placeholder(placeholder_ct) if placeholder_ct == self => { Some(ty) } _ => None, } } _ => None, } }); let ty = candidates.next().unwrap(); assert!(candidates.next().is_none()); ty } } pub type PlaceholderRegion = Placeholder; impl rustc_type_ir::inherent::PlaceholderLike for PlaceholderRegion { fn universe(self) -> UniverseIndex { self.universe } fn var(self) -> BoundVar { self.bound.var } fn with_updated_universe(self, ui: UniverseIndex) -> Self { Placeholder { universe: ui, ..self } } fn new(ui: UniverseIndex, var: BoundVar) -> Self { Placeholder { universe: ui, bound: BoundRegion { var, kind: BoundRegionKind::Anon } } } } pub type PlaceholderType = Placeholder; impl rustc_type_ir::inherent::PlaceholderLike for PlaceholderType { fn universe(self) -> UniverseIndex { self.universe } fn var(self) -> BoundVar { self.bound.var } fn with_updated_universe(self, ui: UniverseIndex) -> Self { Placeholder { universe: ui, ..self } } fn new(ui: UniverseIndex, var: BoundVar) -> Self { Placeholder { universe: ui, bound: BoundTy { var, kind: BoundTyKind::Anon } } } } #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, HashStable)] #[derive(TyEncodable, TyDecodable)] pub struct BoundConst<'tcx> { pub var: BoundVar, pub ty: Ty<'tcx>, } pub type PlaceholderConst = Placeholder; impl rustc_type_ir::inherent::PlaceholderLike for PlaceholderConst { fn universe(self) -> UniverseIndex { self.universe } fn var(self) -> BoundVar { self.bound } fn with_updated_universe(self, ui: UniverseIndex) -> Self { Placeholder { universe: ui, ..self } } fn new(ui: UniverseIndex, var: BoundVar) -> Self { Placeholder { universe: ui, bound: var } } } pub type Clauses<'tcx> = &'tcx ListWithCachedTypeInfo>; impl<'tcx> rustc_type_ir::Flags for Clauses<'tcx> { fn flags(&self) -> TypeFlags { (**self).flags() } fn outer_exclusive_binder(&self) -> DebruijnIndex { (**self).outer_exclusive_binder() } } /// When interacting with the type system we must provide information about the /// environment. `ParamEnv` is the type that represents this information. See the /// [dev guide chapter][param_env_guide] for more information. /// /// [param_env_guide]: https://rustc-dev-guide.rust-lang.org/param_env/param_env_summary.html #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)] #[derive(HashStable, TypeVisitable, TypeFoldable)] pub struct ParamEnv<'tcx> { /// Caller bounds are `Obligation`s that the caller must satisfy. This is /// basically the set of bounds on the in-scope type parameters, translated /// into `Obligation`s, and elaborated and normalized. /// /// Use the `caller_bounds()` method to access. caller_bounds: Clauses<'tcx>, } impl<'tcx> rustc_type_ir::inherent::ParamEnv> for ParamEnv<'tcx> { fn caller_bounds(self) -> impl inherent::SliceLike> { self.caller_bounds() } } impl<'tcx> ParamEnv<'tcx> { /// Construct a trait environment suitable for contexts where there are /// no where-clauses in scope. In the majority of cases it is incorrect /// to use an empty environment. See the [dev guide section][param_env_guide] /// for information on what a `ParamEnv` is and how to acquire one. /// /// [param_env_guide]: https://rustc-dev-guide.rust-lang.org/param_env/param_env_summary.html #[inline] pub fn empty() -> Self { Self::new(ListWithCachedTypeInfo::empty()) } #[inline] pub fn caller_bounds(self) -> Clauses<'tcx> { self.caller_bounds } /// Construct a trait environment with the given set of predicates. #[inline] pub fn new(caller_bounds: Clauses<'tcx>) -> Self { ParamEnv { caller_bounds } } /// Creates a pair of param-env and value for use in queries. pub fn and>>(self, value: T) -> ParamEnvAnd<'tcx, T> { ParamEnvAnd { param_env: self, value } } } #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, TypeFoldable, TypeVisitable)] #[derive(HashStable)] pub struct ParamEnvAnd<'tcx, T> { pub param_env: ParamEnv<'tcx>, pub value: T, } impl<'tcx, T> ParamEnvAnd<'tcx, T> { pub fn into_parts(self) -> (ParamEnv<'tcx>, T) { (self.param_env, self.value) } } /// The environment in which to do trait solving. /// /// Most of the time you only need to care about the `ParamEnv` /// as the `TypingMode` is simply stored in the `InferCtxt`. /// /// However, there are some places which rely on trait solving /// without using an `InferCtxt` themselves. For these to be /// able to use the trait system they have to be able to initialize /// such an `InferCtxt` with the right `typing_mode`, so they need /// to track both. #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, HashStable)] #[derive(TypeVisitable, TypeFoldable)] pub struct TypingEnv<'tcx> { pub typing_mode: TypingMode<'tcx>, pub param_env: ParamEnv<'tcx>, } impl<'tcx> TypingEnv<'tcx> { /// Create a typing environment with no where-clauses in scope /// where all opaque types and default associated items are revealed. /// /// This is only suitable for monomorphized, post-typeck environments. /// Do not use this for MIR optimizations, as even though they also /// use `TypingMode::PostAnalysis`, they may still have where-clauses /// in scope. pub fn fully_monomorphized() -> TypingEnv<'tcx> { TypingEnv { typing_mode: TypingMode::PostAnalysis, param_env: ParamEnv::empty() } } /// Create a typing environment for use during analysis outside of a body. /// /// Using a typing environment inside of bodies is not supported as the body /// may define opaque types. In this case the used functions have to be /// converted to use proper canonical inputs instead. pub fn non_body_analysis( tcx: TyCtxt<'tcx>, def_id: impl IntoQueryParam, ) -> TypingEnv<'tcx> { TypingEnv { typing_mode: TypingMode::non_body_analysis(), param_env: tcx.param_env(def_id) } } pub fn post_analysis(tcx: TyCtxt<'tcx>, def_id: impl IntoQueryParam) -> TypingEnv<'tcx> { TypingEnv { typing_mode: TypingMode::PostAnalysis, param_env: tcx.param_env_normalized_for_post_analysis(def_id), } } /// Modify the `typing_mode` to `PostAnalysis` and eagerly reveal all /// opaque types in the `param_env`. pub fn with_post_analysis_normalized(self, tcx: TyCtxt<'tcx>) -> TypingEnv<'tcx> { let TypingEnv { typing_mode, param_env } = self; if let TypingMode::PostAnalysis = typing_mode { return self; } // No need to reveal opaques with the new solver enabled, // since we have lazy norm. let param_env = if tcx.next_trait_solver_globally() { ParamEnv::new(param_env.caller_bounds()) } else { ParamEnv::new(tcx.reveal_opaque_types_in_bounds(param_env.caller_bounds())) }; TypingEnv { typing_mode: TypingMode::PostAnalysis, param_env } } /// Combine this typing environment with the given `value` to be used by /// not (yet) canonicalized queries. This only works if the value does not /// contain anything local to some `InferCtxt`, i.e. inference variables or /// placeholders. pub fn as_query_input(self, value: T) -> PseudoCanonicalInput<'tcx, T> where T: TypeVisitable>, { // FIXME(#132279): We should assert that the value does not contain any placeholders // as these placeholders are also local to the current inference context. However, we // currently use pseudo-canonical queries in the trait solver which replaces params with // placeholders. We should also simply not use pseudo-canonical queries in the trait // solver, at which point we can readd this assert. As of writing this comment, this is // only used by `fn layout_is_pointer_like` when calling `layout_of`. // // debug_assert!(!value.has_placeholders()); PseudoCanonicalInput { typing_env: self, value } } } /// Similar to `CanonicalInput`, this carries the `typing_mode` and the environment /// necessary to do any kind of trait solving inside of nested queries. /// /// Unlike proper canonicalization, this requires the `param_env` and the `value` to not /// contain anything local to the `infcx` of the caller, so we don't actually canonicalize /// anything. /// /// This should be created by using `infcx.pseudo_canonicalize_query(param_env, value)` /// or by using `typing_env.as_query_input(value)`. #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)] #[derive(HashStable, TypeVisitable, TypeFoldable)] pub struct PseudoCanonicalInput<'tcx, T> { pub typing_env: TypingEnv<'tcx>, pub value: T, } #[derive(Copy, Clone, Debug, HashStable, Encodable, Decodable)] pub struct Destructor { /// The `DefId` of the destructor method pub did: DefId, /// The constness of the destructor method pub constness: hir::Constness, } // FIXME: consider combining this definition with regular `Destructor` #[derive(Copy, Clone, Debug, HashStable, Encodable, Decodable)] pub struct AsyncDestructor { /// The `DefId` of the async destructor future constructor pub ctor: DefId, /// The `DefId` of the async destructor future type pub future: DefId, } #[derive(Clone, Copy, PartialEq, Eq, HashStable, TyEncodable, TyDecodable)] pub struct VariantFlags(u8); bitflags::bitflags! { impl VariantFlags: u8 { const NO_VARIANT_FLAGS = 0; /// Indicates whether the field list of this variant is `#[non_exhaustive]`. const IS_FIELD_LIST_NON_EXHAUSTIVE = 1 << 0; } } rustc_data_structures::external_bitflags_debug! { VariantFlags } /// Definition of a variant -- a struct's fields or an enum variant. #[derive(Debug, HashStable, TyEncodable, TyDecodable)] pub struct VariantDef { /// `DefId` that identifies the variant itself. /// If this variant belongs to a struct or union, then this is a copy of its `DefId`. pub def_id: DefId, /// `DefId` that identifies the variant's constructor. /// If this variant is a struct variant, then this is `None`. pub ctor: Option<(CtorKind, DefId)>, /// Variant or struct name. pub name: Symbol, /// Discriminant of this variant. pub discr: VariantDiscr, /// Fields of this variant. pub fields: IndexVec, /// The error guarantees from parser, if any. tainted: Option, /// Flags of the variant (e.g. is field list non-exhaustive)? flags: VariantFlags, } impl VariantDef { /// Creates a new `VariantDef`. /// /// `variant_did` is the `DefId` that identifies the enum variant (if this `VariantDef` /// represents an enum variant). /// /// `ctor_did` is the `DefId` that identifies the constructor of unit or /// tuple-variants/structs. If this is a `struct`-variant then this should be `None`. /// /// `parent_did` is the `DefId` of the `AdtDef` representing the enum or struct that /// owns this variant. It is used for checking if a struct has `#[non_exhaustive]` w/out having /// to go through the redirect of checking the ctor's attributes - but compiling a small crate /// requires loading the `AdtDef`s for all the structs in the universe (e.g., coherence for any /// built-in trait), and we do not want to load attributes twice. /// /// If someone speeds up attribute loading to not be a performance concern, they can /// remove this hack and use the constructor `DefId` everywhere. #[instrument(level = "debug")] pub fn new( name: Symbol, variant_did: Option, ctor: Option<(CtorKind, DefId)>, discr: VariantDiscr, fields: IndexVec, parent_did: DefId, recover_tainted: Option, is_field_list_non_exhaustive: bool, ) -> Self { let mut flags = VariantFlags::NO_VARIANT_FLAGS; if is_field_list_non_exhaustive { flags |= VariantFlags::IS_FIELD_LIST_NON_EXHAUSTIVE; } VariantDef { def_id: variant_did.unwrap_or(parent_did), ctor, name, discr, fields, flags, tainted: recover_tainted, } } /// Is this field list non-exhaustive? #[inline] pub fn is_field_list_non_exhaustive(&self) -> bool { self.flags.intersects(VariantFlags::IS_FIELD_LIST_NON_EXHAUSTIVE) } /// Computes the `Ident` of this variant by looking up the `Span` pub fn ident(&self, tcx: TyCtxt<'_>) -> Ident { Ident::new(self.name, tcx.def_ident_span(self.def_id).unwrap()) } /// Was this variant obtained as part of recovering from a syntactic error? #[inline] pub fn has_errors(&self) -> Result<(), ErrorGuaranteed> { self.tainted.map_or(Ok(()), Err) } #[inline] pub fn ctor_kind(&self) -> Option { self.ctor.map(|(kind, _)| kind) } #[inline] pub fn ctor_def_id(&self) -> Option { self.ctor.map(|(_, def_id)| def_id) } /// Returns the one field in this variant. /// /// `panic!`s if there are no fields or multiple fields. #[inline] pub fn single_field(&self) -> &FieldDef { assert!(self.fields.len() == 1); &self.fields[FieldIdx::ZERO] } /// Returns the last field in this variant, if present. #[inline] pub fn tail_opt(&self) -> Option<&FieldDef> { self.fields.raw.last() } /// Returns the last field in this variant. /// /// # Panics /// /// Panics, if the variant has no fields. #[inline] pub fn tail(&self) -> &FieldDef { self.tail_opt().expect("expected unsized ADT to have a tail field") } /// Returns whether this variant has unsafe fields. pub fn has_unsafe_fields(&self) -> bool { self.fields.iter().any(|x| x.safety.is_unsafe()) } } impl PartialEq for VariantDef { #[inline] fn eq(&self, other: &Self) -> bool { // There should be only one `VariantDef` for each `def_id`, therefore // it is fine to implement `PartialEq` only based on `def_id`. // // Below, we exhaustively destructure `self` and `other` so that if the // definition of `VariantDef` changes, a compile-error will be produced, // reminding us to revisit this assumption. let Self { def_id: lhs_def_id, ctor: _, name: _, discr: _, fields: _, flags: _, tainted: _, } = &self; let Self { def_id: rhs_def_id, ctor: _, name: _, discr: _, fields: _, flags: _, tainted: _, } = other; let res = lhs_def_id == rhs_def_id; // Double check that implicit assumption detailed above. if cfg!(debug_assertions) && res { let deep = self.ctor == other.ctor && self.name == other.name && self.discr == other.discr && self.fields == other.fields && self.flags == other.flags; assert!(deep, "VariantDef for the same def-id has differing data"); } res } } impl Eq for VariantDef {} impl Hash for VariantDef { #[inline] fn hash(&self, s: &mut H) { // There should be only one `VariantDef` for each `def_id`, therefore // it is fine to implement `Hash` only based on `def_id`. // // Below, we exhaustively destructure `self` so that if the definition // of `VariantDef` changes, a compile-error will be produced, reminding // us to revisit this assumption. let Self { def_id, ctor: _, name: _, discr: _, fields: _, flags: _, tainted: _ } = &self; def_id.hash(s) } } #[derive(Copy, Clone, Debug, PartialEq, Eq, TyEncodable, TyDecodable, HashStable)] pub enum VariantDiscr { /// Explicit value for this variant, i.e., `X = 123`. /// The `DefId` corresponds to the embedded constant. Explicit(DefId), /// The previous variant's discriminant plus one. /// For efficiency reasons, the distance from the /// last `Explicit` discriminant is being stored, /// or `0` for the first variant, if it has none. Relative(u32), } #[derive(Debug, HashStable, TyEncodable, TyDecodable)] pub struct FieldDef { pub did: DefId, pub name: Symbol, pub vis: Visibility, pub safety: hir::Safety, pub value: Option, } impl PartialEq for FieldDef { #[inline] fn eq(&self, other: &Self) -> bool { // There should be only one `FieldDef` for each `did`, therefore it is // fine to implement `PartialEq` only based on `did`. // // Below, we exhaustively destructure `self` so that if the definition // of `FieldDef` changes, a compile-error will be produced, reminding // us to revisit this assumption. let Self { did: lhs_did, name: _, vis: _, safety: _, value: _ } = &self; let Self { did: rhs_did, name: _, vis: _, safety: _, value: _ } = other; let res = lhs_did == rhs_did; // Double check that implicit assumption detailed above. if cfg!(debug_assertions) && res { let deep = self.name == other.name && self.vis == other.vis && self.safety == other.safety; assert!(deep, "FieldDef for the same def-id has differing data"); } res } } impl Eq for FieldDef {} impl Hash for FieldDef { #[inline] fn hash(&self, s: &mut H) { // There should be only one `FieldDef` for each `did`, therefore it is // fine to implement `Hash` only based on `did`. // // Below, we exhaustively destructure `self` so that if the definition // of `FieldDef` changes, a compile-error will be produced, reminding // us to revisit this assumption. let Self { did, name: _, vis: _, safety: _, value: _ } = &self; did.hash(s) } } impl<'tcx> FieldDef { /// Returns the type of this field. The resulting type is not normalized. The `arg` is /// typically obtained via the second field of [`TyKind::Adt`]. pub fn ty(&self, tcx: TyCtxt<'tcx>, args: GenericArgsRef<'tcx>) -> Ty<'tcx> { tcx.type_of(self.did).instantiate(tcx, args) } /// Computes the `Ident` of this variant by looking up the `Span` pub fn ident(&self, tcx: TyCtxt<'_>) -> Ident { Ident::new(self.name, tcx.def_ident_span(self.did).unwrap()) } } #[derive(Debug, PartialEq, Eq)] pub enum ImplOverlapKind { /// These impls are always allowed to overlap. Permitted { /// Whether or not the impl is permitted due to the trait being a `#[marker]` trait marker: bool, }, } /// Useful source information about where a desugared associated type for an /// RPITIT originated from. #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, Encodable, Decodable, HashStable)] pub enum ImplTraitInTraitData { Trait { fn_def_id: DefId, opaque_def_id: DefId }, Impl { fn_def_id: DefId }, } impl<'tcx> TyCtxt<'tcx> { pub fn typeck_body(self, body: hir::BodyId) -> &'tcx TypeckResults<'tcx> { self.typeck(self.hir_body_owner_def_id(body)) } pub fn provided_trait_methods(self, id: DefId) -> impl 'tcx + Iterator { self.associated_items(id) .in_definition_order() .filter(move |item| item.kind == AssocKind::Fn && item.defaultness(self).has_value()) } pub fn repr_options_of_def(self, did: LocalDefId) -> ReprOptions { let mut flags = ReprFlags::empty(); let mut size = None; let mut max_align: Option = None; let mut min_pack: Option = None; // Generate a deterministically-derived seed from the item's path hash // to allow for cross-crate compilation to actually work let mut field_shuffle_seed = self.def_path_hash(did.to_def_id()).0.to_smaller_hash(); // If the user defined a custom seed for layout randomization, xor the item's // path hash with the user defined seed, this will allowing determinism while // still allowing users to further randomize layout generation for e.g. fuzzing if let Some(user_seed) = self.sess.opts.unstable_opts.layout_seed { field_shuffle_seed ^= user_seed; } if let Some(reprs) = attr::find_attr!(self.get_all_attrs(did), AttributeKind::Repr(r) => r) { for (r, _) in reprs { flags.insert(match *r { attr::ReprRust => ReprFlags::empty(), attr::ReprC => ReprFlags::IS_C, attr::ReprPacked(pack) => { min_pack = Some(if let Some(min_pack) = min_pack { min_pack.min(pack) } else { pack }); ReprFlags::empty() } attr::ReprTransparent => ReprFlags::IS_TRANSPARENT, attr::ReprSimd => ReprFlags::IS_SIMD, attr::ReprInt(i) => { size = Some(match i { attr::IntType::SignedInt(x) => match x { ast::IntTy::Isize => IntegerType::Pointer(true), ast::IntTy::I8 => IntegerType::Fixed(Integer::I8, true), ast::IntTy::I16 => IntegerType::Fixed(Integer::I16, true), ast::IntTy::I32 => IntegerType::Fixed(Integer::I32, true), ast::IntTy::I64 => IntegerType::Fixed(Integer::I64, true), ast::IntTy::I128 => IntegerType::Fixed(Integer::I128, true), }, attr::IntType::UnsignedInt(x) => match x { ast::UintTy::Usize => IntegerType::Pointer(false), ast::UintTy::U8 => IntegerType::Fixed(Integer::I8, false), ast::UintTy::U16 => IntegerType::Fixed(Integer::I16, false), ast::UintTy::U32 => IntegerType::Fixed(Integer::I32, false), ast::UintTy::U64 => IntegerType::Fixed(Integer::I64, false), ast::UintTy::U128 => IntegerType::Fixed(Integer::I128, false), }, }); ReprFlags::empty() } attr::ReprAlign(align) => { max_align = max_align.max(Some(align)); ReprFlags::empty() } attr::ReprEmpty => { /* skip these, they're just for diagnostics */ ReprFlags::empty() } }); } } // If `-Z randomize-layout` was enabled for the type definition then we can // consider performing layout randomization if self.sess.opts.unstable_opts.randomize_layout { flags.insert(ReprFlags::RANDOMIZE_LAYOUT); } // box is special, on the one hand the compiler assumes an ordered layout, with the pointer // always at offset zero. On the other hand we want scalar abi optimizations. let is_box = self.is_lang_item(did.to_def_id(), LangItem::OwnedBox); // This is here instead of layout because the choice must make it into metadata. if is_box { flags.insert(ReprFlags::IS_LINEAR); } ReprOptions { int: size, align: max_align, pack: min_pack, flags, field_shuffle_seed } } /// Look up the name of a definition across crates. This does not look at HIR. pub fn opt_item_name(self, def_id: DefId) -> Option { if let Some(cnum) = def_id.as_crate_root() { Some(self.crate_name(cnum)) } else { let def_key = self.def_key(def_id); match def_key.disambiguated_data.data { // The name of a constructor is that of its parent. rustc_hir::definitions::DefPathData::Ctor => self .opt_item_name(DefId { krate: def_id.krate, index: def_key.parent.unwrap() }), _ => def_key.get_opt_name(), } } } /// Look up the name of a definition across crates. This does not look at HIR. /// /// This method will ICE if the corresponding item does not have a name. In these cases, use /// [`opt_item_name`] instead. /// /// [`opt_item_name`]: Self::opt_item_name pub fn item_name(self, id: DefId) -> Symbol { self.opt_item_name(id).unwrap_or_else(|| { bug!("item_name: no name for {:?}", self.def_path(id)); }) } /// Look up the name and span of a definition. /// /// See [`item_name`][Self::item_name] for more information. pub fn opt_item_ident(self, def_id: DefId) -> Option { let def = self.opt_item_name(def_id)?; let span = self .def_ident_span(def_id) .unwrap_or_else(|| bug!("missing ident span for {def_id:?}")); Some(Ident::new(def, span)) } /// Look up the name and span of a definition. /// /// See [`item_name`][Self::item_name] for more information. pub fn item_ident(self, def_id: DefId) -> Ident { self.opt_item_ident(def_id).unwrap_or_else(|| { bug!("item_ident: no name for {:?}", self.def_path(def_id)); }) } pub fn opt_associated_item(self, def_id: DefId) -> Option { if let DefKind::AssocConst | DefKind::AssocFn | DefKind::AssocTy = self.def_kind(def_id) { Some(self.associated_item(def_id)) } else { None } } /// If the `def_id` is an associated type that was desugared from a /// return-position `impl Trait` from a trait, then provide the source info /// about where that RPITIT came from. pub fn opt_rpitit_info(self, def_id: DefId) -> Option { if let DefKind::AssocTy = self.def_kind(def_id) { self.associated_item(def_id).opt_rpitit_info } else { None } } pub fn find_field_index(self, ident: Ident, variant: &VariantDef) -> Option { variant.fields.iter_enumerated().find_map(|(i, field)| { self.hygienic_eq(ident, field.ident(self), variant.def_id).then_some(i) }) } /// Returns `Some` if the impls are the same polarity and the trait either /// has no items or is annotated `#[marker]` and prevents item overrides. #[instrument(level = "debug", skip(self), ret)] pub fn impls_are_allowed_to_overlap( self, def_id1: DefId, def_id2: DefId, ) -> Option { let impl1 = self.impl_trait_header(def_id1).unwrap(); let impl2 = self.impl_trait_header(def_id2).unwrap(); let trait_ref1 = impl1.trait_ref.skip_binder(); let trait_ref2 = impl2.trait_ref.skip_binder(); // If either trait impl references an error, they're allowed to overlap, // as one of them essentially doesn't exist. if trait_ref1.references_error() || trait_ref2.references_error() { return Some(ImplOverlapKind::Permitted { marker: false }); } match (impl1.polarity, impl2.polarity) { (ImplPolarity::Reservation, _) | (_, ImplPolarity::Reservation) => { // `#[rustc_reservation_impl]` impls don't overlap with anything return Some(ImplOverlapKind::Permitted { marker: false }); } (ImplPolarity::Positive, ImplPolarity::Negative) | (ImplPolarity::Negative, ImplPolarity::Positive) => { // `impl AutoTrait for Type` + `impl !AutoTrait for Type` return None; } (ImplPolarity::Positive, ImplPolarity::Positive) | (ImplPolarity::Negative, ImplPolarity::Negative) => {} }; let is_marker_impl = |trait_ref: TraitRef<'_>| self.trait_def(trait_ref.def_id).is_marker; let is_marker_overlap = is_marker_impl(trait_ref1) && is_marker_impl(trait_ref2); if is_marker_overlap { return Some(ImplOverlapKind::Permitted { marker: true }); } None } /// Returns `ty::VariantDef` if `res` refers to a struct, /// or variant or their constructors, panics otherwise. pub fn expect_variant_res(self, res: Res) -> &'tcx VariantDef { match res { Res::Def(DefKind::Variant, did) => { let enum_did = self.parent(did); self.adt_def(enum_did).variant_with_id(did) } Res::Def(DefKind::Struct | DefKind::Union, did) => self.adt_def(did).non_enum_variant(), Res::Def(DefKind::Ctor(CtorOf::Variant, ..), variant_ctor_did) => { let variant_did = self.parent(variant_ctor_did); let enum_did = self.parent(variant_did); self.adt_def(enum_did).variant_with_ctor_id(variant_ctor_did) } Res::Def(DefKind::Ctor(CtorOf::Struct, ..), ctor_did) => { let struct_did = self.parent(ctor_did); self.adt_def(struct_did).non_enum_variant() } _ => bug!("expect_variant_res used with unexpected res {:?}", res), } } /// Returns the possibly-auto-generated MIR of a [`ty::InstanceKind`]. #[instrument(skip(self), level = "debug")] pub fn instance_mir(self, instance: ty::InstanceKind<'tcx>) -> &'tcx Body<'tcx> { match instance { ty::InstanceKind::Item(def) => { debug!("calling def_kind on def: {:?}", def); let def_kind = self.def_kind(def); debug!("returned from def_kind: {:?}", def_kind); match def_kind { DefKind::Const | DefKind::Static { .. } | DefKind::AssocConst | DefKind::Ctor(..) | DefKind::AnonConst | DefKind::InlineConst => self.mir_for_ctfe(def), // If the caller wants `mir_for_ctfe` of a function they should not be using // `instance_mir`, so we'll assume const fn also wants the optimized version. _ => self.optimized_mir(def), } } ty::InstanceKind::VTableShim(..) | ty::InstanceKind::ReifyShim(..) | ty::InstanceKind::Intrinsic(..) | ty::InstanceKind::FnPtrShim(..) | ty::InstanceKind::Virtual(..) | ty::InstanceKind::ClosureOnceShim { .. } | ty::InstanceKind::ConstructCoroutineInClosureShim { .. } | ty::InstanceKind::DropGlue(..) | ty::InstanceKind::CloneShim(..) | ty::InstanceKind::ThreadLocalShim(..) | ty::InstanceKind::FnPtrAddrShim(..) | ty::InstanceKind::AsyncDropGlueCtorShim(..) => self.mir_shims(instance), } } // FIXME(@lcnr): Remove this function. pub fn get_attrs_unchecked(self, did: DefId) -> &'tcx [hir::Attribute] { if let Some(did) = did.as_local() { self.hir_attrs(self.local_def_id_to_hir_id(did)) } else { self.attrs_for_def(did) } } /// Gets all attributes with the given name. pub fn get_attrs( self, did: impl Into, attr: Symbol, ) -> impl Iterator { self.get_all_attrs(did).filter(move |a: &&hir::Attribute| a.has_name(attr)) } /// Gets all attributes. /// /// To see if an item has a specific attribute, you should use [`rustc_attr_data_structures::find_attr!`] so you can use matching. pub fn get_all_attrs( self, did: impl Into, ) -> impl Iterator { let did: DefId = did.into(); if let Some(did) = did.as_local() { self.hir_attrs(self.local_def_id_to_hir_id(did)).iter() } else { self.attrs_for_def(did).iter() } } /// Get an attribute from the diagnostic attribute namespace /// /// This function requests an attribute with the following structure: /// /// `#[diagnostic::$attr]` /// /// This function performs feature checking, so if an attribute is returned /// it can be used by the consumer pub fn get_diagnostic_attr( self, did: impl Into, attr: Symbol, ) -> Option<&'tcx hir::Attribute> { let did: DefId = did.into(); if did.as_local().is_some() { // it's a crate local item, we need to check feature flags if rustc_feature::is_stable_diagnostic_attribute(attr, self.features()) { self.get_attrs_by_path(did, &[sym::diagnostic, sym::do_not_recommend]).next() } else { None } } else { // we filter out unstable diagnostic attributes before // encoding attributes debug_assert!(rustc_feature::encode_cross_crate(attr)); self.attrs_for_def(did) .iter() .find(|a| matches!(a.path().as_ref(), [sym::diagnostic, a] if *a == attr)) } } pub fn get_attrs_by_path( self, did: DefId, attr: &[Symbol], ) -> impl Iterator { let filter_fn = move |a: &&hir::Attribute| a.path_matches(attr); if let Some(did) = did.as_local() { self.hir_attrs(self.local_def_id_to_hir_id(did)).iter().filter(filter_fn) } else { self.attrs_for_def(did).iter().filter(filter_fn) } } pub fn get_attr(self, did: impl Into, attr: Symbol) -> Option<&'tcx hir::Attribute> { if cfg!(debug_assertions) && !rustc_feature::is_valid_for_get_attr(attr) { let did: DefId = did.into(); 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. pub fn has_attr(self, did: impl Into, attr: Symbol) -> bool { self.get_attrs(did, attr).next().is_some() } /// Determines whether an item is annotated with a multi-segment attribute pub fn has_attrs_with_path(self, did: impl Into, attrs: &[Symbol]) -> bool { self.get_attrs_by_path(did.into(), attrs).next().is_some() } /// Returns `true` if this is an `auto trait`. pub fn trait_is_auto(self, trait_def_id: DefId) -> bool { self.trait_def(trait_def_id).has_auto_impl } /// Returns `true` if this is coinductive, either because it is /// an auto trait or because it has the `#[rustc_coinductive]` attribute. pub fn trait_is_coinductive(self, trait_def_id: DefId) -> bool { self.trait_def(trait_def_id).is_coinductive } /// Returns `true` if this is a trait alias. pub fn trait_is_alias(self, trait_def_id: DefId) -> bool { self.def_kind(trait_def_id) == DefKind::TraitAlias } /// Returns layout of a coroutine. Layout might be unavailable if the /// coroutine is tainted by errors. /// /// Takes `coroutine_kind` which can be acquired from the `CoroutineArgs::kind_ty`, /// e.g. `args.as_coroutine().kind_ty()`. pub fn coroutine_layout( self, def_id: DefId, coroutine_kind_ty: Ty<'tcx>, ) -> Option<&'tcx CoroutineLayout<'tcx>> { let mir = self.optimized_mir(def_id); // Regular coroutine if coroutine_kind_ty.is_unit() { mir.coroutine_layout_raw() } else { // If we have a `Coroutine` that comes from an coroutine-closure, // then it may be a by-move or by-ref body. let ty::Coroutine(_, identity_args) = *self.type_of(def_id).instantiate_identity().kind() else { unreachable!(); }; let identity_kind_ty = identity_args.as_coroutine().kind_ty(); // If the types differ, then we must be getting the by-move body of // a by-ref coroutine. if identity_kind_ty == coroutine_kind_ty { mir.coroutine_layout_raw() } else { assert_matches!(coroutine_kind_ty.to_opt_closure_kind(), Some(ClosureKind::FnOnce)); assert_matches!( identity_kind_ty.to_opt_closure_kind(), Some(ClosureKind::Fn | ClosureKind::FnMut) ); self.optimized_mir(self.coroutine_by_move_body_def_id(def_id)) .coroutine_layout_raw() } } } /// Given the `DefId` of an impl, returns the `DefId` of the trait it implements. /// If it implements no trait, returns `None`. pub fn trait_id_of_impl(self, def_id: DefId) -> Option { self.impl_trait_ref(def_id).map(|tr| tr.skip_binder().def_id) } /// If the given `DefId` describes an item belonging to a trait, /// returns the `DefId` of the trait that the trait item belongs to; /// otherwise, returns `None`. pub fn trait_of_item(self, def_id: DefId) -> Option { if let DefKind::AssocConst | DefKind::AssocFn | DefKind::AssocTy = self.def_kind(def_id) { let parent = self.parent(def_id); if let DefKind::Trait | DefKind::TraitAlias = self.def_kind(parent) { return Some(parent); } } None } /// If the given `DefId` describes a method belonging to an impl, returns the /// `DefId` of the impl that the method belongs to; otherwise, returns `None`. pub fn impl_of_method(self, def_id: DefId) -> Option { if let DefKind::AssocConst | DefKind::AssocFn | DefKind::AssocTy = self.def_kind(def_id) { let parent = self.parent(def_id); if let DefKind::Impl { .. } = self.def_kind(parent) { return Some(parent); } } None } /// Check if the given `DefId` is `#\[automatically_derived\]`, *and* /// whether it was produced by expanding a builtin derive macro. pub fn is_builtin_derived(self, def_id: DefId) -> bool { if self.is_automatically_derived(def_id) && let Some(def_id) = def_id.as_local() && let outer = self.def_span(def_id).ctxt().outer_expn_data() && matches!(outer.kind, ExpnKind::Macro(MacroKind::Derive, _)) && self.has_attr(outer.macro_def_id.unwrap(), sym::rustc_builtin_macro) { true } else { false } } /// Check if the given `DefId` is `#\[automatically_derived\]`. pub fn is_automatically_derived(self, def_id: DefId) -> bool { self.has_attr(def_id, sym::automatically_derived) } /// Looks up the span of `impl_did` if the impl is local; otherwise returns `Err` /// with the name of the crate containing the impl. pub fn span_of_impl(self, impl_def_id: DefId) -> Result { if let Some(impl_def_id) = impl_def_id.as_local() { Ok(self.def_span(impl_def_id)) } else { Err(self.crate_name(impl_def_id.krate)) } } /// Hygienically compares a use-site name (`use_name`) for a field or an associated item with /// its supposed definition name (`def_name`). The method also needs `DefId` of the supposed /// definition's parent/scope to perform comparison. pub fn hygienic_eq(self, use_name: Ident, def_name: Ident, def_parent_def_id: DefId) -> bool { // We could use `Ident::eq` here, but we deliberately don't. The name // comparison fails frequently, and we want to avoid the expensive // `normalize_to_macros_2_0()` calls required for the span comparison whenever possible. use_name.name == def_name.name && use_name .span .ctxt() .hygienic_eq(def_name.span.ctxt(), self.expn_that_defined(def_parent_def_id)) } pub fn adjust_ident(self, mut ident: Ident, scope: DefId) -> Ident { ident.span.normalize_to_macros_2_0_and_adjust(self.expn_that_defined(scope)); ident } // FIXME(vincenzopalazzo): move the HirId to a LocalDefId pub fn adjust_ident_and_get_scope( self, mut ident: Ident, scope: DefId, block: hir::HirId, ) -> (Ident, DefId) { let scope = ident .span .normalize_to_macros_2_0_and_adjust(self.expn_that_defined(scope)) .and_then(|actual_expansion| actual_expansion.expn_data().parent_module) .unwrap_or_else(|| self.parent_module(block).to_def_id()); (ident, scope) } /// Checks whether this is a `const fn`. Returns `false` for non-functions. /// /// Even if this returns `true`, constness may still be unstable! #[inline] pub fn is_const_fn(self, def_id: DefId) -> bool { matches!( self.def_kind(def_id), DefKind::Fn | DefKind::AssocFn | DefKind::Ctor(_, CtorKind::Fn) | DefKind::Closure ) && self.constness(def_id) == hir::Constness::Const } /// Whether this item is conditionally constant for the purposes of the /// effects implementation. /// /// This roughly corresponds to all const functions and other callable /// items, along with const impls and traits, and associated types within /// those impls and traits. pub fn is_conditionally_const(self, def_id: impl Into) -> bool { let def_id: DefId = def_id.into(); match self.def_kind(def_id) { DefKind::Impl { of_trait: true } => { let header = self.impl_trait_header(def_id).unwrap(); header.constness == hir::Constness::Const && self.is_const_trait(header.trait_ref.skip_binder().def_id) } DefKind::Fn | DefKind::Ctor(_, CtorKind::Fn) => { self.constness(def_id) == hir::Constness::Const } DefKind::Trait => self.is_const_trait(def_id), DefKind::AssocTy => { let parent_def_id = self.parent(def_id); match self.def_kind(parent_def_id) { DefKind::Impl { of_trait: false } => false, DefKind::Impl { of_trait: true } | DefKind::Trait => { self.is_conditionally_const(parent_def_id) } _ => bug!("unexpected parent item of associated type: {parent_def_id:?}"), } } DefKind::AssocFn => { let parent_def_id = self.parent(def_id); match self.def_kind(parent_def_id) { DefKind::Impl { of_trait: false } => { self.constness(def_id) == hir::Constness::Const } DefKind::Impl { of_trait: true } | DefKind::Trait => { self.is_conditionally_const(parent_def_id) } _ => bug!("unexpected parent item of associated fn: {parent_def_id:?}"), } } DefKind::OpaqueTy => match self.opaque_ty_origin(def_id) { hir::OpaqueTyOrigin::FnReturn { parent, .. } => self.is_conditionally_const(parent), hir::OpaqueTyOrigin::AsyncFn { .. } => false, // FIXME(const_trait_impl): ATPITs could be conditionally const? hir::OpaqueTyOrigin::TyAlias { .. } => false, }, DefKind::Closure => { // Closures and RPITs will eventually have const conditions // for `~const` bounds. false } DefKind::Ctor(_, CtorKind::Const) | DefKind::Impl { of_trait: false } | DefKind::Mod | DefKind::Struct | DefKind::Union | DefKind::Enum | DefKind::Variant | DefKind::TyAlias | DefKind::ForeignTy | DefKind::TraitAlias | DefKind::TyParam | DefKind::Const | DefKind::ConstParam | DefKind::Static { .. } | DefKind::AssocConst | DefKind::Macro(_) | DefKind::ExternCrate | DefKind::Use | DefKind::ForeignMod | DefKind::AnonConst | DefKind::InlineConst | DefKind::Field | DefKind::LifetimeParam | DefKind::GlobalAsm | DefKind::SyntheticCoroutineBody => false, } } #[inline] pub fn is_const_trait(self, def_id: DefId) -> bool { self.trait_def(def_id).constness == hir::Constness::Const } #[inline] pub fn is_const_default_method(self, def_id: DefId) -> bool { matches!(self.trait_of_item(def_id), Some(trait_id) if self.is_const_trait(trait_id)) } pub fn impl_method_has_trait_impl_trait_tys(self, def_id: DefId) -> bool { if self.def_kind(def_id) != DefKind::AssocFn { return false; } let Some(item) = self.opt_associated_item(def_id) else { return false; }; if item.container != ty::AssocItemContainer::Impl { return false; } let Some(trait_item_def_id) = item.trait_item_def_id else { return false; }; return !self .associated_types_for_impl_traits_in_associated_fn(trait_item_def_id) .is_empty(); } } pub fn int_ty(ity: ast::IntTy) -> IntTy { match ity { ast::IntTy::Isize => IntTy::Isize, ast::IntTy::I8 => IntTy::I8, ast::IntTy::I16 => IntTy::I16, ast::IntTy::I32 => IntTy::I32, ast::IntTy::I64 => IntTy::I64, ast::IntTy::I128 => IntTy::I128, } } pub fn uint_ty(uty: ast::UintTy) -> UintTy { match uty { ast::UintTy::Usize => UintTy::Usize, ast::UintTy::U8 => UintTy::U8, ast::UintTy::U16 => UintTy::U16, ast::UintTy::U32 => UintTy::U32, ast::UintTy::U64 => UintTy::U64, ast::UintTy::U128 => UintTy::U128, } } pub fn float_ty(fty: ast::FloatTy) -> FloatTy { match fty { ast::FloatTy::F16 => FloatTy::F16, ast::FloatTy::F32 => FloatTy::F32, ast::FloatTy::F64 => FloatTy::F64, ast::FloatTy::F128 => FloatTy::F128, } } pub fn ast_int_ty(ity: IntTy) -> ast::IntTy { match ity { IntTy::Isize => ast::IntTy::Isize, IntTy::I8 => ast::IntTy::I8, IntTy::I16 => ast::IntTy::I16, IntTy::I32 => ast::IntTy::I32, IntTy::I64 => ast::IntTy::I64, IntTy::I128 => ast::IntTy::I128, } } pub fn ast_uint_ty(uty: UintTy) -> ast::UintTy { match uty { UintTy::Usize => ast::UintTy::Usize, UintTy::U8 => ast::UintTy::U8, UintTy::U16 => ast::UintTy::U16, UintTy::U32 => ast::UintTy::U32, UintTy::U64 => ast::UintTy::U64, UintTy::U128 => ast::UintTy::U128, } } pub fn provide(providers: &mut Providers) { closure::provide(providers); context::provide(providers); erase_regions::provide(providers); inhabitedness::provide(providers); util::provide(providers); print::provide(providers); super::util::bug::provide(providers); *providers = Providers { trait_impls_of: trait_def::trait_impls_of_provider, incoherent_impls: trait_def::incoherent_impls_provider, trait_impls_in_crate: trait_def::trait_impls_in_crate_provider, traits: trait_def::traits_provider, vtable_allocation: vtable::vtable_allocation_provider, ..*providers }; } /// A map for the local crate mapping each type to a vector of its /// inherent impls. This is not meant to be used outside of coherence; /// rather, you should request the vector for a specific type via /// `tcx.inherent_impls(def_id)` so as to minimize your dependencies /// (constructing this map requires touching the entire crate). #[derive(Clone, Debug, Default, HashStable)] pub struct CrateInherentImpls { pub inherent_impls: FxIndexMap>, pub incoherent_impls: FxIndexMap>, } #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, TyEncodable, HashStable)] pub struct SymbolName<'tcx> { /// `&str` gives a consistent ordering, which ensures reproducible builds. pub name: &'tcx str, } impl<'tcx> SymbolName<'tcx> { pub fn new(tcx: TyCtxt<'tcx>, name: &str) -> SymbolName<'tcx> { SymbolName { name: tcx.arena.alloc_str(name) } } } impl<'tcx> fmt::Display for SymbolName<'tcx> { fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { fmt::Display::fmt(&self.name, fmt) } } impl<'tcx> fmt::Debug for SymbolName<'tcx> { fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { fmt::Display::fmt(&self.name, fmt) } } #[derive(Debug, Default, Copy, Clone)] pub struct InferVarInfo { /// This is true if we identified that this Ty (`?T`) is found in a `?T: Foo` /// obligation, where: /// /// * `Foo` is not `Sized` /// * `(): Foo` may be satisfied pub self_in_trait: bool, /// This is true if we identified that this Ty (`?T`) is found in a `<_ as /// _>::AssocType = ?T` pub output: bool, } /// The constituent parts of a type level constant of kind ADT or array. #[derive(Copy, Clone, Debug, HashStable)] pub struct DestructuredConst<'tcx> { pub variant: Option, pub fields: &'tcx [ty::Const<'tcx>], } // Some types are used a lot. Make sure they don't unintentionally get bigger. #[cfg(target_pointer_width = "64")] mod size_asserts { use rustc_data_structures::static_assert_size; use super::*; // tidy-alphabetical-start static_assert_size!(PredicateKind<'_>, 32); static_assert_size!(WithCachedTypeInfo>, 48); // tidy-alphabetical-end }