//! This module contains `TyKind` and its major components. #![allow(rustc::usage_of_ty_tykind)] use std::assert_matches::debug_assert_matches; use std::borrow::Cow; use std::ops::{ControlFlow, Range}; use hir::def::{CtorKind, DefKind}; use rustc_abi::{FIRST_VARIANT, FieldIdx, VariantIdx}; use rustc_errors::{ErrorGuaranteed, MultiSpan}; use rustc_hir as hir; use rustc_hir::LangItem; use rustc_hir::def_id::DefId; use rustc_macros::{HashStable, TyDecodable, TyEncodable, TypeFoldable, extension}; use rustc_span::{DUMMY_SP, Span, Symbol, sym}; use rustc_type_ir::TyKind::*; use rustc_type_ir::solve::SizedTraitKind; use rustc_type_ir::walk::TypeWalker; use rustc_type_ir::{self as ir, BoundVar, CollectAndApply, DynKind, TypeVisitableExt, elaborate}; use tracing::instrument; use ty::util::IntTypeExt; use super::GenericParamDefKind; use crate::infer::canonical::Canonical; use crate::ty::InferTy::*; use crate::ty::{ self, AdtDef, BoundRegionKind, Discr, GenericArg, GenericArgs, GenericArgsRef, List, ParamEnv, Region, Ty, TyCtxt, TypeFlags, TypeSuperVisitable, TypeVisitable, TypeVisitor, UintTy, }; // Re-export and re-parameterize some `I = TyCtxt<'tcx>` types here #[rustc_diagnostic_item = "TyKind"] pub type TyKind<'tcx> = ir::TyKind>; pub type TypeAndMut<'tcx> = ir::TypeAndMut>; pub type AliasTy<'tcx> = ir::AliasTy>; pub type FnSig<'tcx> = ir::FnSig>; pub type Binder<'tcx, T> = ir::Binder, T>; pub type EarlyBinder<'tcx, T> = ir::EarlyBinder, T>; pub type TypingMode<'tcx> = ir::TypingMode>; pub trait Article { fn article(&self) -> &'static str; } impl<'tcx> Article for TyKind<'tcx> { /// Get the article ("a" or "an") to use with this type. fn article(&self) -> &'static str { match self { Int(_) | Float(_) | Array(_, _) => "an", Adt(def, _) if def.is_enum() => "an", // This should never happen, but ICEing and causing the user's code // to not compile felt too harsh. Error(_) => "a", _ => "a", } } } #[extension(pub trait CoroutineArgsExt<'tcx>)] impl<'tcx> ty::CoroutineArgs> { /// Coroutine has not been resumed yet. const UNRESUMED: usize = 0; /// Coroutine has returned or is completed. const RETURNED: usize = 1; /// Coroutine has been poisoned. const POISONED: usize = 2; /// Number of variants to reserve in coroutine state. Corresponds to /// `UNRESUMED` (beginning of a coroutine) and `RETURNED`/`POISONED` /// (end of a coroutine) states. const RESERVED_VARIANTS: usize = 3; const UNRESUMED_NAME: &'static str = "Unresumed"; const RETURNED_NAME: &'static str = "Returned"; const POISONED_NAME: &'static str = "Panicked"; /// The valid variant indices of this coroutine. #[inline] fn variant_range(&self, def_id: DefId, tcx: TyCtxt<'tcx>) -> Range { // FIXME requires optimized MIR FIRST_VARIANT..tcx.coroutine_layout(def_id, self.args).unwrap().variant_fields.next_index() } /// The discriminant for the given variant. Panics if the `variant_index` is /// out of range. #[inline] fn discriminant_for_variant( &self, def_id: DefId, tcx: TyCtxt<'tcx>, variant_index: VariantIdx, ) -> Discr<'tcx> { // Coroutines don't support explicit discriminant values, so they are // the same as the variant index. assert!(self.variant_range(def_id, tcx).contains(&variant_index)); Discr { val: variant_index.as_usize() as u128, ty: self.discr_ty(tcx) } } /// The set of all discriminants for the coroutine, enumerated with their /// variant indices. #[inline] fn discriminants( self, def_id: DefId, tcx: TyCtxt<'tcx>, ) -> impl Iterator)> { self.variant_range(def_id, tcx).map(move |index| { (index, Discr { val: index.as_usize() as u128, ty: self.discr_ty(tcx) }) }) } /// Calls `f` with a reference to the name of the enumerator for the given /// variant `v`. fn variant_name(v: VariantIdx) -> Cow<'static, str> { match v.as_usize() { Self::UNRESUMED => Cow::from(Self::UNRESUMED_NAME), Self::RETURNED => Cow::from(Self::RETURNED_NAME), Self::POISONED => Cow::from(Self::POISONED_NAME), _ => Cow::from(format!("Suspend{}", v.as_usize() - Self::RESERVED_VARIANTS)), } } /// The type of the state discriminant used in the coroutine type. #[inline] fn discr_ty(&self, tcx: TyCtxt<'tcx>) -> Ty<'tcx> { tcx.types.u32 } /// This returns the types of the MIR locals which had to be stored across suspension points. /// It is calculated in rustc_mir_transform::coroutine::StateTransform. /// All the types here must be in the tuple in CoroutineInterior. /// /// The locals are grouped by their variant number. Note that some locals may /// be repeated in multiple variants. #[inline] fn state_tys( self, def_id: DefId, tcx: TyCtxt<'tcx>, ) -> impl Iterator>> { let layout = tcx.coroutine_layout(def_id, self.args).unwrap(); layout.variant_fields.iter().map(move |variant| { variant.iter().map(move |field| { if tcx.is_async_drop_in_place_coroutine(def_id) { layout.field_tys[*field].ty } else { ty::EarlyBinder::bind(layout.field_tys[*field].ty).instantiate(tcx, self.args) } }) }) } /// This is the types of the fields of a coroutine which are not stored in a /// variant. #[inline] fn prefix_tys(self) -> &'tcx List> { self.upvar_tys() } } #[derive(Debug, Copy, Clone, HashStable, TypeFoldable, TypeVisitable)] pub enum UpvarArgs<'tcx> { Closure(GenericArgsRef<'tcx>), Coroutine(GenericArgsRef<'tcx>), CoroutineClosure(GenericArgsRef<'tcx>), } impl<'tcx> UpvarArgs<'tcx> { /// Returns an iterator over the list of types of captured paths by the closure/coroutine. /// In case there was a type error in figuring out the types of the captured path, an /// empty iterator is returned. #[inline] pub fn upvar_tys(self) -> &'tcx List> { let tupled_tys = match self { UpvarArgs::Closure(args) => args.as_closure().tupled_upvars_ty(), UpvarArgs::Coroutine(args) => args.as_coroutine().tupled_upvars_ty(), UpvarArgs::CoroutineClosure(args) => args.as_coroutine_closure().tupled_upvars_ty(), }; match tupled_tys.kind() { TyKind::Error(_) => ty::List::empty(), TyKind::Tuple(..) => self.tupled_upvars_ty().tuple_fields(), TyKind::Infer(_) => bug!("upvar_tys called before capture types are inferred"), ty => bug!("Unexpected representation of upvar types tuple {:?}", ty), } } #[inline] pub fn tupled_upvars_ty(self) -> Ty<'tcx> { match self { UpvarArgs::Closure(args) => args.as_closure().tupled_upvars_ty(), UpvarArgs::Coroutine(args) => args.as_coroutine().tupled_upvars_ty(), UpvarArgs::CoroutineClosure(args) => args.as_coroutine_closure().tupled_upvars_ty(), } } } /// An inline const is modeled like /// ```ignore (illustrative) /// const InlineConst<'l0...'li, T0...Tj, R>: R; /// ``` /// where: /// /// - 'l0...'li and T0...Tj are the generic parameters /// inherited from the item that defined the inline const, /// - R represents the type of the constant. /// /// When the inline const is instantiated, `R` is instantiated as the actual inferred /// type of the constant. The reason that `R` is represented as an extra type parameter /// is the same reason that [`ty::ClosureArgs`] have `CS` and `U` as type parameters: /// inline const can reference lifetimes that are internal to the creating function. #[derive(Copy, Clone, Debug)] pub struct InlineConstArgs<'tcx> { /// Generic parameters from the enclosing item, /// concatenated with the inferred type of the constant. pub args: GenericArgsRef<'tcx>, } /// Struct returned by `split()`. pub struct InlineConstArgsParts<'tcx, T> { pub parent_args: &'tcx [GenericArg<'tcx>], pub ty: T, } impl<'tcx> InlineConstArgs<'tcx> { /// Construct `InlineConstArgs` from `InlineConstArgsParts`. pub fn new( tcx: TyCtxt<'tcx>, parts: InlineConstArgsParts<'tcx, Ty<'tcx>>, ) -> InlineConstArgs<'tcx> { InlineConstArgs { args: tcx.mk_args_from_iter( parts.parent_args.iter().copied().chain(std::iter::once(parts.ty.into())), ), } } /// Divides the inline const args into their respective components. /// The ordering assumed here must match that used by `InlineConstArgs::new` above. fn split(self) -> InlineConstArgsParts<'tcx, GenericArg<'tcx>> { match self.args[..] { [ref parent_args @ .., ty] => InlineConstArgsParts { parent_args, ty }, _ => bug!("inline const args missing synthetics"), } } /// Returns the generic parameters of the inline const's parent. pub fn parent_args(self) -> &'tcx [GenericArg<'tcx>] { self.split().parent_args } /// Returns the type of this inline const. pub fn ty(self) -> Ty<'tcx> { self.split().ty.expect_ty() } } #[derive(Copy, Clone, PartialEq, Eq, Hash, Debug, TyEncodable, TyDecodable)] #[derive(HashStable)] pub enum BoundVariableKind { Ty(BoundTyKind), Region(BoundRegionKind), Const, } impl BoundVariableKind { pub fn expect_region(self) -> BoundRegionKind { match self { BoundVariableKind::Region(lt) => lt, _ => bug!("expected a region, but found another kind"), } } pub fn expect_ty(self) -> BoundTyKind { match self { BoundVariableKind::Ty(ty) => ty, _ => bug!("expected a type, but found another kind"), } } pub fn expect_const(self) { match self { BoundVariableKind::Const => (), _ => bug!("expected a const, but found another kind"), } } } pub type PolyFnSig<'tcx> = Binder<'tcx, FnSig<'tcx>>; pub type CanonicalPolyFnSig<'tcx> = Canonical<'tcx, Binder<'tcx, FnSig<'tcx>>>; #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, TyEncodable, TyDecodable)] #[derive(HashStable)] pub struct ParamTy { pub index: u32, pub name: Symbol, } impl rustc_type_ir::inherent::ParamLike for ParamTy { fn index(self) -> u32 { self.index } } impl<'tcx> ParamTy { pub fn new(index: u32, name: Symbol) -> ParamTy { ParamTy { index, name } } pub fn for_def(def: &ty::GenericParamDef) -> ParamTy { ParamTy::new(def.index, def.name) } #[inline] pub fn to_ty(self, tcx: TyCtxt<'tcx>) -> Ty<'tcx> { Ty::new_param(tcx, self.index, self.name) } pub fn span_from_generics(self, tcx: TyCtxt<'tcx>, item_with_generics: DefId) -> Span { let generics = tcx.generics_of(item_with_generics); let type_param = generics.type_param(self, tcx); tcx.def_span(type_param.def_id) } } #[derive(Copy, Clone, Hash, TyEncodable, TyDecodable, Eq, PartialEq, Ord, PartialOrd)] #[derive(HashStable)] pub struct ParamConst { pub index: u32, pub name: Symbol, } impl rustc_type_ir::inherent::ParamLike for ParamConst { fn index(self) -> u32 { self.index } } impl ParamConst { pub fn new(index: u32, name: Symbol) -> ParamConst { ParamConst { index, name } } pub fn for_def(def: &ty::GenericParamDef) -> ParamConst { ParamConst::new(def.index, def.name) } #[instrument(level = "debug")] 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(param_ct, ty) => { assert!(!(param_ct, ty).has_escaping_bound_vars()); match param_ct.kind() { ty::ConstKind::Param(param_ct) if param_ct.index == self.index => Some(ty), _ => None, } } _ => None, } }); // N.B. it may be tempting to fix ICEs by making this function return // `Option>` instead of `Ty<'tcx>`; however, this is generally // considered to be a bandaid solution, since it hides more important // underlying issues with how we construct generics and predicates of // items. It's advised to fix the underlying issue rather than trying // to modify this function. let ty = candidates.next().unwrap_or_else(|| { bug!("cannot find `{self:?}` in param-env: {env:#?}"); }); assert!( candidates.next().is_none(), "did not expect duplicate `ConstParamHasTy` for `{self:?}` in param-env: {env:#?}" ); ty } } #[derive(Clone, Copy, PartialEq, Eq, Hash, TyEncodable, TyDecodable)] #[derive(HashStable)] pub struct BoundTy { pub var: BoundVar, pub kind: BoundTyKind, } impl<'tcx> rustc_type_ir::inherent::BoundVarLike> for BoundTy { fn var(self) -> BoundVar { self.var } fn assert_eq(self, var: ty::BoundVariableKind) { assert_eq!(self.kind, var.expect_ty()) } } #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug, TyEncodable, TyDecodable)] #[derive(HashStable)] pub enum BoundTyKind { Anon, Param(DefId), } /// Constructors for `Ty` impl<'tcx> Ty<'tcx> { /// Avoid using this in favour of more specific `new_*` methods, where possible. /// The more specific methods will often optimize their creation. #[allow(rustc::usage_of_ty_tykind)] #[inline] fn new(tcx: TyCtxt<'tcx>, st: TyKind<'tcx>) -> Ty<'tcx> { tcx.mk_ty_from_kind(st) } #[inline] pub fn new_infer(tcx: TyCtxt<'tcx>, infer: ty::InferTy) -> Ty<'tcx> { Ty::new(tcx, TyKind::Infer(infer)) } #[inline] pub fn new_var(tcx: TyCtxt<'tcx>, v: ty::TyVid) -> Ty<'tcx> { // Use a pre-interned one when possible. tcx.types .ty_vars .get(v.as_usize()) .copied() .unwrap_or_else(|| Ty::new(tcx, Infer(TyVar(v)))) } #[inline] pub fn new_int_var(tcx: TyCtxt<'tcx>, v: ty::IntVid) -> Ty<'tcx> { Ty::new_infer(tcx, IntVar(v)) } #[inline] pub fn new_float_var(tcx: TyCtxt<'tcx>, v: ty::FloatVid) -> Ty<'tcx> { Ty::new_infer(tcx, FloatVar(v)) } #[inline] pub fn new_fresh(tcx: TyCtxt<'tcx>, n: u32) -> Ty<'tcx> { // Use a pre-interned one when possible. tcx.types .fresh_tys .get(n as usize) .copied() .unwrap_or_else(|| Ty::new_infer(tcx, ty::FreshTy(n))) } #[inline] pub fn new_fresh_int(tcx: TyCtxt<'tcx>, n: u32) -> Ty<'tcx> { // Use a pre-interned one when possible. tcx.types .fresh_int_tys .get(n as usize) .copied() .unwrap_or_else(|| Ty::new_infer(tcx, ty::FreshIntTy(n))) } #[inline] pub fn new_fresh_float(tcx: TyCtxt<'tcx>, n: u32) -> Ty<'tcx> { // Use a pre-interned one when possible. tcx.types .fresh_float_tys .get(n as usize) .copied() .unwrap_or_else(|| Ty::new_infer(tcx, ty::FreshFloatTy(n))) } #[inline] pub fn new_param(tcx: TyCtxt<'tcx>, index: u32, name: Symbol) -> Ty<'tcx> { Ty::new(tcx, Param(ParamTy { index, name })) } #[inline] pub fn new_bound( tcx: TyCtxt<'tcx>, index: ty::DebruijnIndex, bound_ty: ty::BoundTy, ) -> Ty<'tcx> { // Use a pre-interned one when possible. if let ty::BoundTy { var, kind: ty::BoundTyKind::Anon } = bound_ty && let Some(inner) = tcx.types.anon_bound_tys.get(index.as_usize()) && let Some(ty) = inner.get(var.as_usize()).copied() { ty } else { Ty::new(tcx, Bound(index, bound_ty)) } } #[inline] pub fn new_placeholder(tcx: TyCtxt<'tcx>, placeholder: ty::PlaceholderType) -> Ty<'tcx> { Ty::new(tcx, Placeholder(placeholder)) } #[inline] pub fn new_alias( tcx: TyCtxt<'tcx>, kind: ty::AliasTyKind, alias_ty: ty::AliasTy<'tcx>, ) -> Ty<'tcx> { debug_assert_matches!( (kind, tcx.def_kind(alias_ty.def_id)), (ty::Opaque, DefKind::OpaqueTy) | (ty::Projection | ty::Inherent, DefKind::AssocTy) | (ty::Free, DefKind::TyAlias) ); Ty::new(tcx, Alias(kind, alias_ty)) } #[inline] pub fn new_pat(tcx: TyCtxt<'tcx>, base: Ty<'tcx>, pat: ty::Pattern<'tcx>) -> Ty<'tcx> { Ty::new(tcx, Pat(base, pat)) } #[inline] #[instrument(level = "debug", skip(tcx))] pub fn new_opaque(tcx: TyCtxt<'tcx>, def_id: DefId, args: GenericArgsRef<'tcx>) -> Ty<'tcx> { Ty::new_alias(tcx, ty::Opaque, AliasTy::new_from_args(tcx, def_id, args)) } /// Constructs a `TyKind::Error` type with current `ErrorGuaranteed` pub fn new_error(tcx: TyCtxt<'tcx>, guar: ErrorGuaranteed) -> Ty<'tcx> { Ty::new(tcx, Error(guar)) } /// Constructs a `TyKind::Error` type and registers a `span_delayed_bug` to ensure it gets used. #[track_caller] pub fn new_misc_error(tcx: TyCtxt<'tcx>) -> Ty<'tcx> { Ty::new_error_with_message(tcx, DUMMY_SP, "TyKind::Error constructed but no error reported") } /// Constructs a `TyKind::Error` type and registers a `span_delayed_bug` with the given `msg` to /// ensure it gets used. #[track_caller] pub fn new_error_with_message>( tcx: TyCtxt<'tcx>, span: S, msg: impl Into>, ) -> Ty<'tcx> { let reported = tcx.dcx().span_delayed_bug(span, msg); Ty::new(tcx, Error(reported)) } #[inline] pub fn new_int(tcx: TyCtxt<'tcx>, i: ty::IntTy) -> Ty<'tcx> { use ty::IntTy::*; match i { Isize => tcx.types.isize, I8 => tcx.types.i8, I16 => tcx.types.i16, I32 => tcx.types.i32, I64 => tcx.types.i64, I128 => tcx.types.i128, } } #[inline] pub fn new_uint(tcx: TyCtxt<'tcx>, ui: ty::UintTy) -> Ty<'tcx> { use ty::UintTy::*; match ui { Usize => tcx.types.usize, U8 => tcx.types.u8, U16 => tcx.types.u16, U32 => tcx.types.u32, U64 => tcx.types.u64, U128 => tcx.types.u128, } } #[inline] pub fn new_float(tcx: TyCtxt<'tcx>, f: ty::FloatTy) -> Ty<'tcx> { use ty::FloatTy::*; match f { F16 => tcx.types.f16, F32 => tcx.types.f32, F64 => tcx.types.f64, F128 => tcx.types.f128, } } #[inline] pub fn new_ref( tcx: TyCtxt<'tcx>, r: Region<'tcx>, ty: Ty<'tcx>, mutbl: ty::Mutability, ) -> Ty<'tcx> { Ty::new(tcx, Ref(r, ty, mutbl)) } #[inline] pub fn new_mut_ref(tcx: TyCtxt<'tcx>, r: Region<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> { Ty::new_ref(tcx, r, ty, hir::Mutability::Mut) } #[inline] pub fn new_imm_ref(tcx: TyCtxt<'tcx>, r: Region<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> { Ty::new_ref(tcx, r, ty, hir::Mutability::Not) } pub fn new_pinned_ref( tcx: TyCtxt<'tcx>, r: Region<'tcx>, ty: Ty<'tcx>, mutbl: ty::Mutability, ) -> Ty<'tcx> { let pin = tcx.adt_def(tcx.require_lang_item(LangItem::Pin, DUMMY_SP)); Ty::new_adt(tcx, pin, tcx.mk_args(&[Ty::new_ref(tcx, r, ty, mutbl).into()])) } #[inline] pub fn new_ptr(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>, mutbl: ty::Mutability) -> Ty<'tcx> { Ty::new(tcx, ty::RawPtr(ty, mutbl)) } #[inline] pub fn new_mut_ptr(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> { Ty::new_ptr(tcx, ty, hir::Mutability::Mut) } #[inline] pub fn new_imm_ptr(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> { Ty::new_ptr(tcx, ty, hir::Mutability::Not) } #[inline] pub fn new_adt(tcx: TyCtxt<'tcx>, def: AdtDef<'tcx>, args: GenericArgsRef<'tcx>) -> Ty<'tcx> { tcx.debug_assert_args_compatible(def.did(), args); if cfg!(debug_assertions) { match tcx.def_kind(def.did()) { DefKind::Struct | DefKind::Union | DefKind::Enum => {} DefKind::Mod | DefKind::Variant | DefKind::Trait | DefKind::TyAlias | DefKind::ForeignTy | DefKind::TraitAlias | DefKind::AssocTy | DefKind::TyParam | DefKind::Fn | DefKind::Const | DefKind::ConstParam | DefKind::Static { .. } | DefKind::Ctor(..) | DefKind::AssocFn | DefKind::AssocConst | DefKind::Macro(..) | DefKind::ExternCrate | DefKind::Use | DefKind::ForeignMod | DefKind::AnonConst | DefKind::InlineConst | DefKind::OpaqueTy | DefKind::Field | DefKind::LifetimeParam | DefKind::GlobalAsm | DefKind::Impl { .. } | DefKind::Closure | DefKind::SyntheticCoroutineBody => { bug!("not an adt: {def:?} ({:?})", tcx.def_kind(def.did())) } } } Ty::new(tcx, Adt(def, args)) } #[inline] pub fn new_foreign(tcx: TyCtxt<'tcx>, def_id: DefId) -> Ty<'tcx> { Ty::new(tcx, Foreign(def_id)) } #[inline] pub fn new_array(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>, n: u64) -> Ty<'tcx> { Ty::new(tcx, Array(ty, ty::Const::from_target_usize(tcx, n))) } #[inline] pub fn new_array_with_const_len( tcx: TyCtxt<'tcx>, ty: Ty<'tcx>, ct: ty::Const<'tcx>, ) -> Ty<'tcx> { Ty::new(tcx, Array(ty, ct)) } #[inline] pub fn new_slice(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> { Ty::new(tcx, Slice(ty)) } #[inline] pub fn new_tup(tcx: TyCtxt<'tcx>, ts: &[Ty<'tcx>]) -> Ty<'tcx> { if ts.is_empty() { tcx.types.unit } else { Ty::new(tcx, Tuple(tcx.mk_type_list(ts))) } } pub fn new_tup_from_iter(tcx: TyCtxt<'tcx>, iter: I) -> T::Output where I: Iterator, T: CollectAndApply, Ty<'tcx>>, { T::collect_and_apply(iter, |ts| Ty::new_tup(tcx, ts)) } #[inline] pub fn new_fn_def( tcx: TyCtxt<'tcx>, def_id: DefId, args: impl IntoIterator>>, ) -> Ty<'tcx> { debug_assert_matches!( tcx.def_kind(def_id), DefKind::AssocFn | DefKind::Fn | DefKind::Ctor(_, CtorKind::Fn) ); let args = tcx.check_and_mk_args(def_id, args); Ty::new(tcx, FnDef(def_id, args)) } #[inline] pub fn new_fn_ptr(tcx: TyCtxt<'tcx>, fty: PolyFnSig<'tcx>) -> Ty<'tcx> { let (sig_tys, hdr) = fty.split(); Ty::new(tcx, FnPtr(sig_tys, hdr)) } #[inline] pub fn new_unsafe_binder(tcx: TyCtxt<'tcx>, b: Binder<'tcx, Ty<'tcx>>) -> Ty<'tcx> { Ty::new(tcx, UnsafeBinder(b.into())) } #[inline] pub fn new_dynamic( tcx: TyCtxt<'tcx>, obj: &'tcx List>, reg: ty::Region<'tcx>, repr: DynKind, ) -> Ty<'tcx> { if cfg!(debug_assertions) { let projection_count = obj .projection_bounds() .filter(|item| !tcx.generics_require_sized_self(item.item_def_id())) .count(); let expected_count: usize = obj .principal_def_id() .into_iter() .flat_map(|principal_def_id| { // NOTE: This should agree with `needed_associated_types` in // dyn trait lowering, or else we'll have ICEs. elaborate::supertraits( tcx, ty::Binder::dummy(ty::TraitRef::identity(tcx, principal_def_id)), ) .map(|principal| { tcx.associated_items(principal.def_id()) .in_definition_order() .filter(|item| item.is_type()) .filter(|item| !item.is_impl_trait_in_trait()) .filter(|item| !tcx.generics_require_sized_self(item.def_id)) .count() }) }) .sum(); assert_eq!( projection_count, expected_count, "expected {obj:?} to have {expected_count} projections, \ but it has {projection_count}" ); } Ty::new(tcx, Dynamic(obj, reg, repr)) } #[inline] pub fn new_projection_from_args( tcx: TyCtxt<'tcx>, item_def_id: DefId, args: ty::GenericArgsRef<'tcx>, ) -> Ty<'tcx> { Ty::new_alias(tcx, ty::Projection, AliasTy::new_from_args(tcx, item_def_id, args)) } #[inline] pub fn new_projection( tcx: TyCtxt<'tcx>, item_def_id: DefId, args: impl IntoIterator>>, ) -> Ty<'tcx> { Ty::new_alias(tcx, ty::Projection, AliasTy::new(tcx, item_def_id, args)) } #[inline] pub fn new_closure( tcx: TyCtxt<'tcx>, def_id: DefId, closure_args: GenericArgsRef<'tcx>, ) -> Ty<'tcx> { tcx.debug_assert_args_compatible(def_id, closure_args); Ty::new(tcx, Closure(def_id, closure_args)) } #[inline] pub fn new_coroutine_closure( tcx: TyCtxt<'tcx>, def_id: DefId, closure_args: GenericArgsRef<'tcx>, ) -> Ty<'tcx> { tcx.debug_assert_args_compatible(def_id, closure_args); Ty::new(tcx, CoroutineClosure(def_id, closure_args)) } #[inline] pub fn new_coroutine( tcx: TyCtxt<'tcx>, def_id: DefId, coroutine_args: GenericArgsRef<'tcx>, ) -> Ty<'tcx> { tcx.debug_assert_args_compatible(def_id, coroutine_args); Ty::new(tcx, Coroutine(def_id, coroutine_args)) } #[inline] pub fn new_coroutine_witness( tcx: TyCtxt<'tcx>, def_id: DefId, args: GenericArgsRef<'tcx>, ) -> Ty<'tcx> { if cfg!(debug_assertions) { tcx.debug_assert_args_compatible(tcx.typeck_root_def_id(def_id), args); } Ty::new(tcx, CoroutineWitness(def_id, args)) } pub fn new_coroutine_witness_for_coroutine( tcx: TyCtxt<'tcx>, def_id: DefId, coroutine_args: GenericArgsRef<'tcx>, ) -> Ty<'tcx> { tcx.debug_assert_args_compatible(def_id, coroutine_args); // HACK: Coroutine witness types are lifetime erased, so they // never reference any lifetime args from the coroutine. We erase // the regions here since we may get into situations where a // coroutine is recursively contained within itself, leading to // witness types that differ by region args. This means that // cycle detection in fulfillment will not kick in, which leads // to unnecessary overflows in async code. See the issue: // . let args = ty::GenericArgs::for_item(tcx, tcx.typeck_root_def_id(def_id), |def, _| { match def.kind { ty::GenericParamDefKind::Lifetime => tcx.lifetimes.re_erased.into(), ty::GenericParamDefKind::Type { .. } | ty::GenericParamDefKind::Const { .. } => coroutine_args[def.index as usize], } }); Ty::new_coroutine_witness(tcx, def_id, args) } // misc #[inline] pub fn new_static_str(tcx: TyCtxt<'tcx>) -> Ty<'tcx> { Ty::new_imm_ref(tcx, tcx.lifetimes.re_static, tcx.types.str_) } #[inline] pub fn new_diverging_default(tcx: TyCtxt<'tcx>) -> Ty<'tcx> { if tcx.features().never_type_fallback() { tcx.types.never } else { tcx.types.unit } } // lang and diagnostic tys fn new_generic_adt(tcx: TyCtxt<'tcx>, wrapper_def_id: DefId, ty_param: Ty<'tcx>) -> Ty<'tcx> { let adt_def = tcx.adt_def(wrapper_def_id); let args = GenericArgs::for_item(tcx, wrapper_def_id, |param, args| match param.kind { GenericParamDefKind::Lifetime | GenericParamDefKind::Const { .. } => bug!(), GenericParamDefKind::Type { has_default, .. } => { if param.index == 0 { ty_param.into() } else { assert!(has_default); tcx.type_of(param.def_id).instantiate(tcx, args).into() } } }); Ty::new_adt(tcx, adt_def, args) } #[inline] pub fn new_lang_item(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>, item: LangItem) -> Option> { let def_id = tcx.lang_items().get(item)?; Some(Ty::new_generic_adt(tcx, def_id, ty)) } #[inline] pub fn new_diagnostic_item(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>, name: Symbol) -> Option> { let def_id = tcx.get_diagnostic_item(name)?; Some(Ty::new_generic_adt(tcx, def_id, ty)) } #[inline] pub fn new_box(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> { let def_id = tcx.require_lang_item(LangItem::OwnedBox, DUMMY_SP); Ty::new_generic_adt(tcx, def_id, ty) } #[inline] pub fn new_maybe_uninit(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> { let def_id = tcx.require_lang_item(LangItem::MaybeUninit, DUMMY_SP); Ty::new_generic_adt(tcx, def_id, ty) } /// Creates a `&mut Context<'_>` [`Ty`] with erased lifetimes. pub fn new_task_context(tcx: TyCtxt<'tcx>) -> Ty<'tcx> { let context_did = tcx.require_lang_item(LangItem::Context, DUMMY_SP); let context_adt_ref = tcx.adt_def(context_did); let context_args = tcx.mk_args(&[tcx.lifetimes.re_erased.into()]); let context_ty = Ty::new_adt(tcx, context_adt_ref, context_args); Ty::new_mut_ref(tcx, tcx.lifetimes.re_erased, context_ty) } } impl<'tcx> rustc_type_ir::inherent::Ty> for Ty<'tcx> { fn new_bool(tcx: TyCtxt<'tcx>) -> Self { tcx.types.bool } fn new_u8(tcx: TyCtxt<'tcx>) -> Self { tcx.types.u8 } fn new_infer(tcx: TyCtxt<'tcx>, infer: ty::InferTy) -> Self { Ty::new_infer(tcx, infer) } fn new_var(tcx: TyCtxt<'tcx>, vid: ty::TyVid) -> Self { Ty::new_var(tcx, vid) } fn new_param(tcx: TyCtxt<'tcx>, param: ty::ParamTy) -> Self { Ty::new_param(tcx, param.index, param.name) } fn new_placeholder(tcx: TyCtxt<'tcx>, placeholder: ty::PlaceholderType) -> Self { Ty::new_placeholder(tcx, placeholder) } fn new_bound(interner: TyCtxt<'tcx>, debruijn: ty::DebruijnIndex, var: ty::BoundTy) -> Self { Ty::new_bound(interner, debruijn, var) } fn new_anon_bound(tcx: TyCtxt<'tcx>, debruijn: ty::DebruijnIndex, var: ty::BoundVar) -> Self { Ty::new_bound(tcx, debruijn, ty::BoundTy { var, kind: ty::BoundTyKind::Anon }) } fn new_alias( interner: TyCtxt<'tcx>, kind: ty::AliasTyKind, alias_ty: ty::AliasTy<'tcx>, ) -> Self { Ty::new_alias(interner, kind, alias_ty) } fn new_error(interner: TyCtxt<'tcx>, guar: ErrorGuaranteed) -> Self { Ty::new_error(interner, guar) } fn new_adt( interner: TyCtxt<'tcx>, adt_def: ty::AdtDef<'tcx>, args: ty::GenericArgsRef<'tcx>, ) -> Self { Ty::new_adt(interner, adt_def, args) } fn new_foreign(interner: TyCtxt<'tcx>, def_id: DefId) -> Self { Ty::new_foreign(interner, def_id) } fn new_dynamic( interner: TyCtxt<'tcx>, preds: &'tcx List>, region: ty::Region<'tcx>, kind: ty::DynKind, ) -> Self { Ty::new_dynamic(interner, preds, region, kind) } fn new_coroutine( interner: TyCtxt<'tcx>, def_id: DefId, args: ty::GenericArgsRef<'tcx>, ) -> Self { Ty::new_coroutine(interner, def_id, args) } fn new_coroutine_closure( interner: TyCtxt<'tcx>, def_id: DefId, args: ty::GenericArgsRef<'tcx>, ) -> Self { Ty::new_coroutine_closure(interner, def_id, args) } fn new_closure(interner: TyCtxt<'tcx>, def_id: DefId, args: ty::GenericArgsRef<'tcx>) -> Self { Ty::new_closure(interner, def_id, args) } fn new_coroutine_witness( interner: TyCtxt<'tcx>, def_id: DefId, args: ty::GenericArgsRef<'tcx>, ) -> Self { Ty::new_coroutine_witness(interner, def_id, args) } fn new_coroutine_witness_for_coroutine( interner: TyCtxt<'tcx>, def_id: DefId, coroutine_args: ty::GenericArgsRef<'tcx>, ) -> Self { Ty::new_coroutine_witness_for_coroutine(interner, def_id, coroutine_args) } fn new_ptr(interner: TyCtxt<'tcx>, ty: Self, mutbl: hir::Mutability) -> Self { Ty::new_ptr(interner, ty, mutbl) } fn new_ref( interner: TyCtxt<'tcx>, region: ty::Region<'tcx>, ty: Self, mutbl: hir::Mutability, ) -> Self { Ty::new_ref(interner, region, ty, mutbl) } fn new_array_with_const_len(interner: TyCtxt<'tcx>, ty: Self, len: ty::Const<'tcx>) -> Self { Ty::new_array_with_const_len(interner, ty, len) } fn new_slice(interner: TyCtxt<'tcx>, ty: Self) -> Self { Ty::new_slice(interner, ty) } fn new_tup(interner: TyCtxt<'tcx>, tys: &[Ty<'tcx>]) -> Self { Ty::new_tup(interner, tys) } fn new_tup_from_iter(interner: TyCtxt<'tcx>, iter: It) -> T::Output where It: Iterator, T: CollectAndApply, { Ty::new_tup_from_iter(interner, iter) } fn tuple_fields(self) -> &'tcx ty::List> { self.tuple_fields() } fn to_opt_closure_kind(self) -> Option { self.to_opt_closure_kind() } fn from_closure_kind(interner: TyCtxt<'tcx>, kind: ty::ClosureKind) -> Self { Ty::from_closure_kind(interner, kind) } fn from_coroutine_closure_kind( interner: TyCtxt<'tcx>, kind: rustc_type_ir::ClosureKind, ) -> Self { Ty::from_coroutine_closure_kind(interner, kind) } fn new_fn_def(interner: TyCtxt<'tcx>, def_id: DefId, args: ty::GenericArgsRef<'tcx>) -> Self { Ty::new_fn_def(interner, def_id, args) } fn new_fn_ptr(interner: TyCtxt<'tcx>, sig: ty::Binder<'tcx, ty::FnSig<'tcx>>) -> Self { Ty::new_fn_ptr(interner, sig) } fn new_pat(interner: TyCtxt<'tcx>, ty: Self, pat: ty::Pattern<'tcx>) -> Self { Ty::new_pat(interner, ty, pat) } fn new_unsafe_binder(interner: TyCtxt<'tcx>, ty: ty::Binder<'tcx, Ty<'tcx>>) -> Self { Ty::new_unsafe_binder(interner, ty) } fn new_unit(interner: TyCtxt<'tcx>) -> Self { interner.types.unit } fn new_usize(interner: TyCtxt<'tcx>) -> Self { interner.types.usize } fn discriminant_ty(self, interner: TyCtxt<'tcx>) -> Ty<'tcx> { self.discriminant_ty(interner) } fn has_unsafe_fields(self) -> bool { Ty::has_unsafe_fields(self) } } /// Type utilities impl<'tcx> Ty<'tcx> { // It would be nicer if this returned the value instead of a reference, // like how `Predicate::kind` and `Region::kind` do. (It would result in // many fewer subsequent dereferences.) But that gives a small but // noticeable performance hit. See #126069 for details. #[inline(always)] pub fn kind(self) -> &'tcx TyKind<'tcx> { self.0.0 } // FIXME(compiler-errors): Think about removing this. #[inline(always)] pub fn flags(self) -> TypeFlags { self.0.0.flags } #[inline] pub fn is_unit(self) -> bool { match self.kind() { Tuple(tys) => tys.is_empty(), _ => false, } } /// Check if type is an `usize`. #[inline] pub fn is_usize(self) -> bool { matches!(self.kind(), Uint(UintTy::Usize)) } /// Check if type is an `usize` or an integral type variable. #[inline] pub fn is_usize_like(self) -> bool { matches!(self.kind(), Uint(UintTy::Usize) | Infer(IntVar(_))) } #[inline] pub fn is_never(self) -> bool { matches!(self.kind(), Never) } #[inline] pub fn is_primitive(self) -> bool { matches!(self.kind(), Bool | Char | Int(_) | Uint(_) | Float(_)) } #[inline] pub fn is_adt(self) -> bool { matches!(self.kind(), Adt(..)) } #[inline] pub fn is_ref(self) -> bool { matches!(self.kind(), Ref(..)) } #[inline] pub fn is_ty_var(self) -> bool { matches!(self.kind(), Infer(TyVar(_))) } #[inline] pub fn ty_vid(self) -> Option { match self.kind() { &Infer(TyVar(vid)) => Some(vid), _ => None, } } #[inline] pub fn is_ty_or_numeric_infer(self) -> bool { matches!(self.kind(), Infer(_)) } #[inline] pub fn is_phantom_data(self) -> bool { if let Adt(def, _) = self.kind() { def.is_phantom_data() } else { false } } #[inline] pub fn is_bool(self) -> bool { *self.kind() == Bool } /// Returns `true` if this type is a `str`. #[inline] pub fn is_str(self) -> bool { *self.kind() == Str } #[inline] pub fn is_param(self, index: u32) -> bool { match self.kind() { ty::Param(data) => data.index == index, _ => false, } } #[inline] pub fn is_slice(self) -> bool { matches!(self.kind(), Slice(_)) } #[inline] pub fn is_array_slice(self) -> bool { match self.kind() { Slice(_) => true, ty::RawPtr(ty, _) | Ref(_, ty, _) => matches!(ty.kind(), Slice(_)), _ => false, } } #[inline] pub fn is_array(self) -> bool { matches!(self.kind(), Array(..)) } #[inline] pub fn is_simd(self) -> bool { match self.kind() { Adt(def, _) => def.repr().simd(), _ => false, } } pub fn sequence_element_type(self, tcx: TyCtxt<'tcx>) -> Ty<'tcx> { match self.kind() { Array(ty, _) | Slice(ty) => *ty, Str => tcx.types.u8, _ => bug!("`sequence_element_type` called on non-sequence value: {}", self), } } pub fn simd_size_and_type(self, tcx: TyCtxt<'tcx>) -> (u64, Ty<'tcx>) { let Adt(def, args) = self.kind() else { bug!("`simd_size_and_type` called on invalid type") }; assert!(def.repr().simd(), "`simd_size_and_type` called on non-SIMD type"); let variant = def.non_enum_variant(); assert_eq!(variant.fields.len(), 1); let field_ty = variant.fields[FieldIdx::ZERO].ty(tcx, args); let Array(f0_elem_ty, f0_len) = field_ty.kind() else { bug!("Simd type has non-array field type {field_ty:?}") }; // FIXME(repr_simd): https://github.com/rust-lang/rust/pull/78863#discussion_r522784112 // The way we evaluate the `N` in `[T; N]` here only works since we use // `simd_size_and_type` post-monomorphization. It will probably start to ICE // if we use it in generic code. See the `simd-array-trait` ui test. ( f0_len .try_to_target_usize(tcx) .expect("expected SIMD field to have definite array size"), *f0_elem_ty, ) } #[inline] pub fn is_mutable_ptr(self) -> bool { matches!(self.kind(), RawPtr(_, hir::Mutability::Mut) | Ref(_, _, hir::Mutability::Mut)) } /// Get the mutability of the reference or `None` when not a reference #[inline] pub fn ref_mutability(self) -> Option { match self.kind() { Ref(_, _, mutability) => Some(*mutability), _ => None, } } #[inline] pub fn is_raw_ptr(self) -> bool { matches!(self.kind(), RawPtr(_, _)) } /// Tests if this is any kind of primitive pointer type (reference, raw pointer, fn pointer). /// `Box` is *not* considered a pointer here! #[inline] pub fn is_any_ptr(self) -> bool { self.is_ref() || self.is_raw_ptr() || self.is_fn_ptr() } #[inline] pub fn is_box(self) -> bool { match self.kind() { Adt(def, _) => def.is_box(), _ => false, } } /// Tests whether this is a Box definitely using the global allocator. /// /// If the allocator is still generic, the answer is `false`, but it may /// later turn out that it does use the global allocator. #[inline] pub fn is_box_global(self, tcx: TyCtxt<'tcx>) -> bool { match self.kind() { Adt(def, args) if def.is_box() => { let Some(alloc) = args.get(1) else { // Single-argument Box is always global. (for "minicore" tests) return true; }; alloc.expect_ty().ty_adt_def().is_some_and(|alloc_adt| { tcx.is_lang_item(alloc_adt.did(), LangItem::GlobalAlloc) }) } _ => false, } } pub fn boxed_ty(self) -> Option> { match self.kind() { Adt(def, args) if def.is_box() => Some(args.type_at(0)), _ => None, } } /// Panics if called on any type other than `Box`. pub fn expect_boxed_ty(self) -> Ty<'tcx> { self.boxed_ty() .unwrap_or_else(|| bug!("`expect_boxed_ty` is called on non-box type {:?}", self)) } /// A scalar type is one that denotes an atomic datum, with no sub-components. /// (A RawPtr is scalar because it represents a non-managed pointer, so its /// contents are abstract to rustc.) #[inline] pub fn is_scalar(self) -> bool { matches!( self.kind(), Bool | Char | Int(_) | Float(_) | Uint(_) | FnDef(..) | FnPtr(..) | RawPtr(_, _) | Infer(IntVar(_) | FloatVar(_)) ) } /// Returns `true` if this type is a floating point type. #[inline] pub fn is_floating_point(self) -> bool { matches!(self.kind(), Float(_) | Infer(FloatVar(_))) } #[inline] pub fn is_trait(self) -> bool { matches!(self.kind(), Dynamic(_, _, ty::Dyn)) } #[inline] pub fn is_enum(self) -> bool { matches!(self.kind(), Adt(adt_def, _) if adt_def.is_enum()) } #[inline] pub fn is_union(self) -> bool { matches!(self.kind(), Adt(adt_def, _) if adt_def.is_union()) } #[inline] pub fn is_closure(self) -> bool { matches!(self.kind(), Closure(..)) } #[inline] pub fn is_coroutine(self) -> bool { matches!(self.kind(), Coroutine(..)) } #[inline] pub fn is_coroutine_closure(self) -> bool { matches!(self.kind(), CoroutineClosure(..)) } #[inline] pub fn is_integral(self) -> bool { matches!(self.kind(), Infer(IntVar(_)) | Int(_) | Uint(_)) } #[inline] pub fn is_fresh_ty(self) -> bool { matches!(self.kind(), Infer(FreshTy(_))) } #[inline] pub fn is_fresh(self) -> bool { matches!(self.kind(), Infer(FreshTy(_) | FreshIntTy(_) | FreshFloatTy(_))) } #[inline] pub fn is_char(self) -> bool { matches!(self.kind(), Char) } #[inline] pub fn is_numeric(self) -> bool { self.is_integral() || self.is_floating_point() } #[inline] pub fn is_signed(self) -> bool { matches!(self.kind(), Int(_)) } #[inline] pub fn is_ptr_sized_integral(self) -> bool { matches!(self.kind(), Int(ty::IntTy::Isize) | Uint(ty::UintTy::Usize)) } #[inline] pub fn has_concrete_skeleton(self) -> bool { !matches!(self.kind(), Param(_) | Infer(_) | Error(_)) } /// Checks whether a type recursively contains another type /// /// Example: `Option<()>` contains `()` pub fn contains(self, other: Ty<'tcx>) -> bool { struct ContainsTyVisitor<'tcx>(Ty<'tcx>); impl<'tcx> TypeVisitor> for ContainsTyVisitor<'tcx> { type Result = ControlFlow<()>; fn visit_ty(&mut self, t: Ty<'tcx>) -> Self::Result { if self.0 == t { ControlFlow::Break(()) } else { t.super_visit_with(self) } } } let cf = self.visit_with(&mut ContainsTyVisitor(other)); cf.is_break() } /// Checks whether a type recursively contains any closure /// /// Example: `Option<{closure@file.rs:4:20}>` returns true pub fn contains_closure(self) -> bool { struct ContainsClosureVisitor; impl<'tcx> TypeVisitor> for ContainsClosureVisitor { type Result = ControlFlow<()>; fn visit_ty(&mut self, t: Ty<'tcx>) -> Self::Result { if let ty::Closure(..) = t.kind() { ControlFlow::Break(()) } else { t.super_visit_with(self) } } } let cf = self.visit_with(&mut ContainsClosureVisitor); cf.is_break() } /// Returns the deepest `async_drop_in_place::{closure}` implementation. /// /// `async_drop_in_place::{closure}`, when T is a coroutine, is a proxy-impl /// to call async drop poll from impl coroutine. pub fn find_async_drop_impl_coroutine)>( self, tcx: TyCtxt<'tcx>, mut f: F, ) -> Ty<'tcx> { assert!(self.is_coroutine()); let mut cor_ty = self; let mut ty = cor_ty; loop { if let ty::Coroutine(def_id, args) = ty.kind() { cor_ty = ty; f(ty); if tcx.is_async_drop_in_place_coroutine(*def_id) { ty = args.first().unwrap().expect_ty(); continue; } else { return cor_ty; } } else { return cor_ty; } } } /// Returns the type of `*ty`. /// /// The parameter `explicit` indicates if this is an *explicit* dereference. /// Some types -- notably raw ptrs -- can only be dereferenced explicitly. pub fn builtin_deref(self, explicit: bool) -> Option> { match *self.kind() { _ if let Some(boxed) = self.boxed_ty() => Some(boxed), Ref(_, ty, _) => Some(ty), RawPtr(ty, _) if explicit => Some(ty), _ => None, } } /// Returns the type of `ty[i]`. pub fn builtin_index(self) -> Option> { match self.kind() { Array(ty, _) | Slice(ty) => Some(*ty), _ => None, } } #[tracing::instrument(level = "trace", skip(tcx))] pub fn fn_sig(self, tcx: TyCtxt<'tcx>) -> PolyFnSig<'tcx> { self.kind().fn_sig(tcx) } #[inline] pub fn is_fn(self) -> bool { matches!(self.kind(), FnDef(..) | FnPtr(..)) } #[inline] pub fn is_fn_ptr(self) -> bool { matches!(self.kind(), FnPtr(..)) } #[inline] pub fn is_impl_trait(self) -> bool { matches!(self.kind(), Alias(ty::Opaque, ..)) } #[inline] pub fn ty_adt_def(self) -> Option> { match self.kind() { Adt(adt, _) => Some(*adt), _ => None, } } /// Iterates over tuple fields. /// Panics when called on anything but a tuple. #[inline] pub fn tuple_fields(self) -> &'tcx List> { match self.kind() { Tuple(args) => args, _ => bug!("tuple_fields called on non-tuple: {self:?}"), } } /// If the type contains variants, returns the valid range of variant indices. // // FIXME: This requires the optimized MIR in the case of coroutines. #[inline] pub fn variant_range(self, tcx: TyCtxt<'tcx>) -> Option> { match self.kind() { TyKind::Adt(adt, _) => Some(adt.variant_range()), TyKind::Coroutine(def_id, args) => { Some(args.as_coroutine().variant_range(*def_id, tcx)) } _ => None, } } /// If the type contains variants, returns the variant for `variant_index`. /// Panics if `variant_index` is out of range. // // FIXME: This requires the optimized MIR in the case of coroutines. #[inline] pub fn discriminant_for_variant( self, tcx: TyCtxt<'tcx>, variant_index: VariantIdx, ) -> Option> { match self.kind() { TyKind::Adt(adt, _) if adt.is_enum() => { Some(adt.discriminant_for_variant(tcx, variant_index)) } TyKind::Coroutine(def_id, args) => { Some(args.as_coroutine().discriminant_for_variant(*def_id, tcx, variant_index)) } _ => None, } } /// Returns the type of the discriminant of this type. pub fn discriminant_ty(self, tcx: TyCtxt<'tcx>) -> Ty<'tcx> { match self.kind() { ty::Adt(adt, _) if adt.is_enum() => adt.repr().discr_type().to_ty(tcx), ty::Coroutine(_, args) => args.as_coroutine().discr_ty(tcx), ty::Param(_) | ty::Alias(..) | ty::Infer(ty::TyVar(_)) => { let assoc_items = tcx.associated_item_def_ids( tcx.require_lang_item(hir::LangItem::DiscriminantKind, DUMMY_SP), ); Ty::new_projection_from_args(tcx, assoc_items[0], tcx.mk_args(&[self.into()])) } ty::Pat(ty, _) => ty.discriminant_ty(tcx), ty::Bool | ty::Char | ty::Int(_) | ty::Uint(_) | ty::Float(_) | ty::Adt(..) | ty::Foreign(_) | ty::Str | ty::Array(..) | ty::Slice(_) | ty::RawPtr(_, _) | ty::Ref(..) | ty::FnDef(..) | ty::FnPtr(..) | ty::Dynamic(..) | ty::Closure(..) | ty::CoroutineClosure(..) | ty::CoroutineWitness(..) | ty::Never | ty::Tuple(_) | ty::UnsafeBinder(_) | ty::Error(_) | ty::Infer(IntVar(_) | FloatVar(_)) => tcx.types.u8, ty::Bound(..) | ty::Placeholder(_) | ty::Infer(FreshTy(_) | ty::FreshIntTy(_) | ty::FreshFloatTy(_)) => { bug!("`discriminant_ty` applied to unexpected type: {:?}", self) } } } /// Returns the type of metadata for (potentially wide) pointers to this type, /// or the struct tail if the metadata type cannot be determined. pub fn ptr_metadata_ty_or_tail( self, tcx: TyCtxt<'tcx>, normalize: impl FnMut(Ty<'tcx>) -> Ty<'tcx>, ) -> Result, Ty<'tcx>> { let tail = tcx.struct_tail_raw(self, normalize, || {}); match tail.kind() { // Sized types ty::Infer(ty::IntVar(_) | ty::FloatVar(_)) | ty::Uint(_) | ty::Int(_) | ty::Bool | ty::Float(_) | ty::FnDef(..) | ty::FnPtr(..) | ty::RawPtr(..) | ty::Char | ty::Ref(..) | ty::Coroutine(..) | ty::CoroutineWitness(..) | ty::Array(..) | ty::Closure(..) | ty::CoroutineClosure(..) | ty::Never | ty::Error(_) // Extern types have metadata = (). | ty::Foreign(..) // If returned by `struct_tail_raw` this is a unit struct // without any fields, or not a struct, and therefore is Sized. | ty::Adt(..) // If returned by `struct_tail_raw` this is the empty tuple, // a.k.a. unit type, which is Sized | ty::Tuple(..) => Ok(tcx.types.unit), ty::Str | ty::Slice(_) => Ok(tcx.types.usize), ty::Dynamic(_, _, ty::Dyn) => { let dyn_metadata = tcx.require_lang_item(LangItem::DynMetadata, DUMMY_SP); Ok(tcx.type_of(dyn_metadata).instantiate(tcx, &[tail.into()])) } // We don't know the metadata of `self`, but it must be equal to the // metadata of `tail`. ty::Param(_) | ty::Alias(..) => Err(tail), | ty::UnsafeBinder(_) => todo!("FIXME(unsafe_binder)"), ty::Infer(ty::TyVar(_)) | ty::Pat(..) | ty::Bound(..) | ty::Placeholder(..) | ty::Infer(ty::FreshTy(_) | ty::FreshIntTy(_) | ty::FreshFloatTy(_)) => bug!( "`ptr_metadata_ty_or_tail` applied to unexpected type: {self:?} (tail = {tail:?})" ), } } /// Returns the type of metadata for (potentially wide) pointers to this type. /// Causes an ICE if the metadata type cannot be determined. pub fn ptr_metadata_ty( self, tcx: TyCtxt<'tcx>, normalize: impl FnMut(Ty<'tcx>) -> Ty<'tcx>, ) -> Ty<'tcx> { match self.ptr_metadata_ty_or_tail(tcx, normalize) { Ok(metadata) => metadata, Err(tail) => bug!( "`ptr_metadata_ty` failed to get metadata for type: {self:?} (tail = {tail:?})" ), } } /// Given a pointer or reference type, returns the type of the *pointee*'s /// metadata. If it can't be determined exactly (perhaps due to still /// being generic) then a projection through `ptr::Pointee` will be returned. /// /// This is particularly useful for getting the type of the result of /// [`UnOp::PtrMetadata`](crate::mir::UnOp::PtrMetadata). /// /// Panics if `self` is not dereferenceable. #[track_caller] pub fn pointee_metadata_ty_or_projection(self, tcx: TyCtxt<'tcx>) -> Ty<'tcx> { let Some(pointee_ty) = self.builtin_deref(true) else { bug!("Type {self:?} is not a pointer or reference type") }; if pointee_ty.has_trivial_sizedness(tcx, SizedTraitKind::Sized) { tcx.types.unit } else { match pointee_ty.ptr_metadata_ty_or_tail(tcx, |x| x) { Ok(metadata_ty) => metadata_ty, Err(tail_ty) => { let metadata_def_id = tcx.require_lang_item(LangItem::Metadata, DUMMY_SP); Ty::new_projection(tcx, metadata_def_id, [tail_ty]) } } } } /// When we create a closure, we record its kind (i.e., what trait /// it implements, constrained by how it uses its borrows) into its /// [`ty::ClosureArgs`] or [`ty::CoroutineClosureArgs`] using a type /// parameter. This is kind of a phantom type, except that the /// most convenient thing for us to are the integral types. This /// function converts such a special type into the closure /// kind. To go the other way, use [`Ty::from_closure_kind`]. /// /// Note that during type checking, we use an inference variable /// to represent the closure kind, because it has not yet been /// inferred. Once upvar inference (in `rustc_hir_analysis/src/check/upvar.rs`) /// is complete, that type variable will be unified with one of /// the integral types. /// /// ```rust,ignore (snippet of compiler code) /// if let TyKind::Closure(def_id, args) = closure_ty.kind() /// && let Some(closure_kind) = args.as_closure().kind_ty().to_opt_closure_kind() /// { /// println!("{closure_kind:?}"); /// } else if let TyKind::CoroutineClosure(def_id, args) = closure_ty.kind() /// && let Some(closure_kind) = args.as_coroutine_closure().kind_ty().to_opt_closure_kind() /// { /// println!("{closure_kind:?}"); /// } /// ``` /// /// After upvar analysis, you should instead use [`ty::ClosureArgs::kind()`] /// or [`ty::CoroutineClosureArgs::kind()`] to assert that the `ClosureKind` /// has been constrained instead of manually calling this method. /// /// ```rust,ignore (snippet of compiler code) /// if let TyKind::Closure(def_id, args) = closure_ty.kind() /// { /// println!("{:?}", args.as_closure().kind()); /// } else if let TyKind::CoroutineClosure(def_id, args) = closure_ty.kind() /// { /// println!("{:?}", args.as_coroutine_closure().kind()); /// } /// ``` pub fn to_opt_closure_kind(self) -> Option { match self.kind() { Int(int_ty) => match int_ty { ty::IntTy::I8 => Some(ty::ClosureKind::Fn), ty::IntTy::I16 => Some(ty::ClosureKind::FnMut), ty::IntTy::I32 => Some(ty::ClosureKind::FnOnce), _ => bug!("cannot convert type `{:?}` to a closure kind", self), }, // "Bound" types appear in canonical queries when the // closure type is not yet known, and `Placeholder` and `Param` // may be encountered in generic `AsyncFnKindHelper` goals. Bound(..) | Placeholder(_) | Param(_) | Infer(_) => None, Error(_) => Some(ty::ClosureKind::Fn), _ => bug!("cannot convert type `{:?}` to a closure kind", self), } } /// Inverse of [`Ty::to_opt_closure_kind`]. See docs on that method /// for explanation of the relationship between `Ty` and [`ty::ClosureKind`]. pub fn from_closure_kind(tcx: TyCtxt<'tcx>, kind: ty::ClosureKind) -> Ty<'tcx> { match kind { ty::ClosureKind::Fn => tcx.types.i8, ty::ClosureKind::FnMut => tcx.types.i16, ty::ClosureKind::FnOnce => tcx.types.i32, } } /// Like [`Ty::to_opt_closure_kind`], but it caps the "maximum" closure kind /// to `FnMut`. This is because although we have three capability states, /// `AsyncFn`/`AsyncFnMut`/`AsyncFnOnce`, we only need to distinguish two coroutine /// bodies: by-ref and by-value. /// /// See the definition of `AsyncFn` and `AsyncFnMut` and the `CallRefFuture` /// associated type for why we don't distinguish [`ty::ClosureKind::Fn`] and /// [`ty::ClosureKind::FnMut`] for the purpose of the generated MIR bodies. /// /// This method should be used when constructing a `Coroutine` out of a /// `CoroutineClosure`, when the `Coroutine`'s `kind` field is being populated /// directly from the `CoroutineClosure`'s `kind`. pub fn from_coroutine_closure_kind(tcx: TyCtxt<'tcx>, kind: ty::ClosureKind) -> Ty<'tcx> { match kind { ty::ClosureKind::Fn | ty::ClosureKind::FnMut => tcx.types.i16, ty::ClosureKind::FnOnce => tcx.types.i32, } } /// Fast path helper for testing if a type is `Sized` or `MetaSized`. /// /// Returning true means the type is known to implement the sizedness trait. Returning `false` /// means nothing -- could be sized, might not be. /// /// Note that we could never rely on the fact that a type such as `[_]` is trivially `!Sized` /// because we could be in a type environment with a bound such as `[_]: Copy`. A function with /// such a bound obviously never can be called, but that doesn't mean it shouldn't typecheck. /// This is why this method doesn't return `Option`. #[instrument(skip(tcx), level = "debug")] pub fn has_trivial_sizedness(self, tcx: TyCtxt<'tcx>, sizedness: SizedTraitKind) -> bool { match self.kind() { ty::Infer(ty::IntVar(_) | ty::FloatVar(_)) | ty::Uint(_) | ty::Int(_) | ty::Bool | ty::Float(_) | ty::FnDef(..) | ty::FnPtr(..) | ty::UnsafeBinder(_) | ty::RawPtr(..) | ty::Char | ty::Ref(..) | ty::Coroutine(..) | ty::CoroutineWitness(..) | ty::Array(..) | ty::Pat(..) | ty::Closure(..) | ty::CoroutineClosure(..) | ty::Never | ty::Error(_) => true, ty::Str | ty::Slice(_) | ty::Dynamic(_, _, ty::Dyn) => match sizedness { SizedTraitKind::Sized => false, SizedTraitKind::MetaSized => true, }, ty::Foreign(..) => match sizedness { SizedTraitKind::Sized | SizedTraitKind::MetaSized => false, }, ty::Tuple(tys) => tys.last().is_none_or(|ty| ty.has_trivial_sizedness(tcx, sizedness)), ty::Adt(def, args) => def .sizedness_constraint(tcx, sizedness) .is_none_or(|ty| ty.instantiate(tcx, args).has_trivial_sizedness(tcx, sizedness)), ty::Alias(..) | ty::Param(_) | ty::Placeholder(..) | ty::Bound(..) => false, ty::Infer(ty::TyVar(_)) => false, ty::Infer(ty::FreshTy(_) | ty::FreshIntTy(_) | ty::FreshFloatTy(_)) => { bug!("`has_trivial_sizedness` applied to unexpected type: {:?}", self) } } } /// Fast path helper for primitives which are always `Copy` and which /// have a side-effect-free `Clone` impl. /// /// Returning true means the type is known to be pure and `Copy+Clone`. /// Returning `false` means nothing -- could be `Copy`, might not be. /// /// This is mostly useful for optimizations, as these are the types /// on which we can replace cloning with dereferencing. pub fn is_trivially_pure_clone_copy(self) -> bool { match self.kind() { ty::Bool | ty::Char | ty::Never => true, // These aren't even `Clone` ty::Str | ty::Slice(..) | ty::Foreign(..) | ty::Dynamic(..) => false, ty::Infer(ty::InferTy::FloatVar(_) | ty::InferTy::IntVar(_)) | ty::Int(..) | ty::Uint(..) | ty::Float(..) => true, // ZST which can't be named are fine. ty::FnDef(..) => true, ty::Array(element_ty, _len) => element_ty.is_trivially_pure_clone_copy(), // A 100-tuple isn't "trivial", so doing this only for reasonable sizes. ty::Tuple(field_tys) => { field_tys.len() <= 3 && field_tys.iter().all(Self::is_trivially_pure_clone_copy) } ty::Pat(ty, _) => ty.is_trivially_pure_clone_copy(), // Sometimes traits aren't implemented for every ABI or arity, // because we can't be generic over everything yet. ty::FnPtr(..) => false, // Definitely absolutely not copy. ty::Ref(_, _, hir::Mutability::Mut) => false, // The standard library has a blanket Copy impl for shared references and raw pointers, // for all unsized types. ty::Ref(_, _, hir::Mutability::Not) | ty::RawPtr(..) => true, ty::Coroutine(..) | ty::CoroutineWitness(..) => false, // Might be, but not "trivial" so just giving the safe answer. ty::Adt(..) | ty::Closure(..) | ty::CoroutineClosure(..) => false, ty::UnsafeBinder(_) => false, // Needs normalization or revealing to determine, so no is the safe answer. ty::Alias(..) => false, ty::Param(..) | ty::Placeholder(..) | ty::Bound(..) | ty::Infer(..) | ty::Error(..) => { false } } } pub fn is_trivially_wf(self, tcx: TyCtxt<'tcx>) -> bool { match *self.kind() { ty::Bool | ty::Char | ty::Int(_) | ty::Uint(_) | ty::Float(_) | ty::Str | ty::Never | ty::Param(_) | ty::Placeholder(_) | ty::Bound(..) => true, ty::Slice(ty) => { ty.is_trivially_wf(tcx) && ty.has_trivial_sizedness(tcx, SizedTraitKind::Sized) } ty::RawPtr(ty, _) => ty.is_trivially_wf(tcx), ty::FnPtr(sig_tys, _) => { sig_tys.skip_binder().inputs_and_output.iter().all(|ty| ty.is_trivially_wf(tcx)) } ty::Ref(_, ty, _) => ty.is_global() && ty.is_trivially_wf(tcx), ty::Infer(infer) => match infer { ty::TyVar(_) => false, ty::IntVar(_) | ty::FloatVar(_) => true, ty::FreshTy(_) | ty::FreshIntTy(_) | ty::FreshFloatTy(_) => true, }, ty::Adt(_, _) | ty::Tuple(_) | ty::Array(..) | ty::Foreign(_) | ty::Pat(_, _) | ty::FnDef(..) | ty::UnsafeBinder(..) | ty::Dynamic(..) | ty::Closure(..) | ty::CoroutineClosure(..) | ty::Coroutine(..) | ty::CoroutineWitness(..) | ty::Alias(..) | ty::Error(_) => false, } } /// If `self` is a primitive, return its [`Symbol`]. pub fn primitive_symbol(self) -> Option { match self.kind() { ty::Bool => Some(sym::bool), ty::Char => Some(sym::char), ty::Float(f) => match f { ty::FloatTy::F16 => Some(sym::f16), ty::FloatTy::F32 => Some(sym::f32), ty::FloatTy::F64 => Some(sym::f64), ty::FloatTy::F128 => Some(sym::f128), }, ty::Int(f) => match f { ty::IntTy::Isize => Some(sym::isize), ty::IntTy::I8 => Some(sym::i8), ty::IntTy::I16 => Some(sym::i16), ty::IntTy::I32 => Some(sym::i32), ty::IntTy::I64 => Some(sym::i64), ty::IntTy::I128 => Some(sym::i128), }, ty::Uint(f) => match f { ty::UintTy::Usize => Some(sym::usize), ty::UintTy::U8 => Some(sym::u8), ty::UintTy::U16 => Some(sym::u16), ty::UintTy::U32 => Some(sym::u32), ty::UintTy::U64 => Some(sym::u64), ty::UintTy::U128 => Some(sym::u128), }, ty::Str => Some(sym::str), _ => None, } } pub fn is_c_void(self, tcx: TyCtxt<'_>) -> bool { match self.kind() { ty::Adt(adt, _) => tcx.is_lang_item(adt.did(), LangItem::CVoid), _ => false, } } pub fn is_async_drop_in_place_coroutine(self, tcx: TyCtxt<'_>) -> bool { match self.kind() { ty::Coroutine(def, ..) => tcx.is_async_drop_in_place_coroutine(*def), _ => false, } } /// Returns `true` when the outermost type cannot be further normalized, /// resolved, or instantiated. This includes all primitive types, but also /// things like ADTs and trait objects, since even if their arguments or /// nested types may be further simplified, the outermost [`TyKind`] or /// type constructor remains the same. pub fn is_known_rigid(self) -> bool { self.kind().is_known_rigid() } /// Iterator that walks `self` and any types reachable from /// `self`, in depth-first order. Note that just walks the types /// that appear in `self`, it does not descend into the fields of /// structs or variants. For example: /// /// ```text /// isize => { isize } /// Foo> => { Foo>, Bar, isize } /// [isize] => { [isize], isize } /// ``` pub fn walk(self) -> TypeWalker> { TypeWalker::new(self.into()) } } impl<'tcx> rustc_type_ir::inherent::Tys> for &'tcx ty::List> { fn inputs(self) -> &'tcx [Ty<'tcx>] { self.split_last().unwrap().1 } fn output(self) -> Ty<'tcx> { *self.split_last().unwrap().0 } } // 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!(TyKind<'_>, 24); static_assert_size!(ty::WithCachedTypeInfo>, 48); // tidy-alphabetical-end }