//! Type context book-keeping. #![allow(rustc::usage_of_ty_tykind)] pub mod tls; use crate::arena::Arena; use crate::dep_graph::{DepGraph, DepKindStruct}; use crate::infer::canonical::CanonicalVarInfo; use crate::lint::struct_lint_level; use crate::metadata::ModChild; use crate::middle::codegen_fn_attrs::CodegenFnAttrs; use crate::middle::resolve_bound_vars; use crate::middle::stability; use crate::mir::interpret::{self, Allocation, ConstAllocation}; use crate::mir::{Body, Local, Place, PlaceElem, ProjectionKind, Promoted}; use crate::query::plumbing::QuerySystem; use crate::query::LocalCrate; use crate::query::Providers; use crate::query::{IntoQueryParam, TyCtxtAt}; use crate::thir::Thir; use crate::traits; use crate::traits::solve; use crate::traits::solve::{ ExternalConstraints, ExternalConstraintsData, PredefinedOpaques, PredefinedOpaquesData, }; use crate::ty::{ self, AdtDef, AdtDefData, AdtKind, Binder, Clause, Const, ConstData, GenericParamDefKind, ImplPolarity, InferTy, List, ParamConst, ParamTy, PolyExistentialPredicate, PolyFnSig, Predicate, PredicateKind, Region, RegionKind, ReprOptions, TraitObjectVisitor, Ty, TyKind, TyVid, TypeAndMut, Visibility, }; use crate::ty::{GenericArg, InternalSubsts, SubstsRef}; use rustc_ast::{self as ast, attr}; use rustc_data_structures::fingerprint::Fingerprint; use rustc_data_structures::fx::{FxHashMap, FxHashSet}; use rustc_data_structures::intern::Interned; use rustc_data_structures::profiling::SelfProfilerRef; use rustc_data_structures::sharded::{IntoPointer, ShardedHashMap}; use rustc_data_structures::stable_hasher::{HashStable, StableHasher}; use rustc_data_structures::steal::Steal; use rustc_data_structures::sync::{self, Lock, Lrc, MappedReadGuard, ReadGuard, WorkerLocal}; use rustc_data_structures::unord::UnordSet; use rustc_errors::{ DecorateLint, DiagnosticBuilder, DiagnosticMessage, ErrorGuaranteed, MultiSpan, }; use rustc_hir as hir; use rustc_hir::def::DefKind; use rustc_hir::def_id::{CrateNum, DefId, LocalDefId, LOCAL_CRATE}; use rustc_hir::definitions::Definitions; use rustc_hir::intravisit::Visitor; use rustc_hir::lang_items::LangItem; use rustc_hir::{ Constness, ExprKind, HirId, ImplItemKind, ItemKind, Node, TraitCandidate, TraitItemKind, }; use rustc_index::IndexVec; use rustc_macros::HashStable; use rustc_query_system::dep_graph::DepNodeIndex; use rustc_query_system::ich::StableHashingContext; use rustc_serialize::opaque::{FileEncodeResult, FileEncoder}; use rustc_session::config::CrateType; use rustc_session::cstore::{CrateStoreDyn, Untracked}; use rustc_session::lint::Lint; use rustc_session::Limit; use rustc_session::Session; use rustc_span::def_id::{DefPathHash, StableCrateId}; use rustc_span::symbol::{kw, sym, Ident, Symbol}; use rustc_span::{Span, DUMMY_SP}; use rustc_target::abi::{FieldIdx, Layout, LayoutS, TargetDataLayout, VariantIdx}; use rustc_target::spec::abi; use rustc_type_ir::sty::TyKind::*; use rustc_type_ir::WithCachedTypeInfo; use rustc_type_ir::{CollectAndApply, Interner, TypeFlags}; use std::any::Any; use std::borrow::Borrow; use std::cmp::Ordering; use std::fmt; use std::hash::{Hash, Hasher}; use std::iter; use std::mem; use std::ops::{Bound, Deref}; #[allow(rustc::usage_of_ty_tykind)] impl<'tcx> Interner for TyCtxt<'tcx> { type AdtDef = ty::AdtDef<'tcx>; type SubstsRef = ty::SubstsRef<'tcx>; type DefId = DefId; type Binder = Binder<'tcx, T>; type Ty = Ty<'tcx>; type Const = ty::Const<'tcx>; type Region = Region<'tcx>; type Predicate = Predicate<'tcx>; type TypeAndMut = TypeAndMut<'tcx>; type Mutability = hir::Mutability; type Movability = hir::Movability; type PolyFnSig = PolyFnSig<'tcx>; type ListBinderExistentialPredicate = &'tcx List>; type BinderListTy = Binder<'tcx, &'tcx List>>; type ListTy = &'tcx List>; type AliasTy = ty::AliasTy<'tcx>; type ParamTy = ParamTy; type BoundTy = ty::BoundTy; type PlaceholderType = ty::PlaceholderType; type InferTy = InferTy; type ErrorGuaranteed = ErrorGuaranteed; type PredicateKind = ty::PredicateKind<'tcx>; type AllocId = crate::mir::interpret::AllocId; type InferConst = ty::InferConst<'tcx>; type AliasConst = ty::UnevaluatedConst<'tcx>; type ParamConst = ty::ParamConst; type BoundConst = ty::BoundVar; type PlaceholderConst = ty::PlaceholderConst<'tcx>; type ValueConst = ty::ValTree<'tcx>; type ExprConst = ty::Expr<'tcx>; type EarlyBoundRegion = ty::EarlyBoundRegion; type BoundRegion = ty::BoundRegion; type FreeRegion = ty::FreeRegion; type RegionVid = ty::RegionVid; type PlaceholderRegion = ty::PlaceholderRegion; fn ty_and_mut_to_parts( TypeAndMut { ty, mutbl }: TypeAndMut<'tcx>, ) -> (Self::Ty, Self::Mutability) { (ty, mutbl) } fn mutability_is_mut(mutbl: Self::Mutability) -> bool { mutbl.is_mut() } } type InternedSet<'tcx, T> = ShardedHashMap, ()>; pub struct CtxtInterners<'tcx> { /// The arena that types, regions, etc. are allocated from. arena: &'tcx WorkerLocal>, // Specifically use a speedy hash algorithm for these hash sets, since // they're accessed quite often. type_: InternedSet<'tcx, WithCachedTypeInfo>>, const_lists: InternedSet<'tcx, List>>, substs: InternedSet<'tcx, InternalSubsts<'tcx>>, type_lists: InternedSet<'tcx, List>>, canonical_var_infos: InternedSet<'tcx, List>>, region: InternedSet<'tcx, RegionKind<'tcx>>, poly_existential_predicates: InternedSet<'tcx, List>>, predicate: InternedSet<'tcx, WithCachedTypeInfo>>>, clauses: InternedSet<'tcx, List>>, projs: InternedSet<'tcx, List>, place_elems: InternedSet<'tcx, List>>, const_: InternedSet<'tcx, ConstData<'tcx>>, const_allocation: InternedSet<'tcx, Allocation>, bound_variable_kinds: InternedSet<'tcx, List>, layout: InternedSet<'tcx, LayoutS>, adt_def: InternedSet<'tcx, AdtDefData>, external_constraints: InternedSet<'tcx, ExternalConstraintsData<'tcx>>, predefined_opaques_in_body: InternedSet<'tcx, PredefinedOpaquesData<'tcx>>, fields: InternedSet<'tcx, List>, } impl<'tcx> CtxtInterners<'tcx> { fn new(arena: &'tcx WorkerLocal>) -> CtxtInterners<'tcx> { CtxtInterners { arena, type_: Default::default(), const_lists: Default::default(), substs: Default::default(), type_lists: Default::default(), region: Default::default(), poly_existential_predicates: Default::default(), canonical_var_infos: Default::default(), predicate: Default::default(), clauses: Default::default(), projs: Default::default(), place_elems: Default::default(), const_: Default::default(), const_allocation: Default::default(), bound_variable_kinds: Default::default(), layout: Default::default(), adt_def: Default::default(), external_constraints: Default::default(), predefined_opaques_in_body: Default::default(), fields: Default::default(), } } /// Interns a type. (Use `mk_*` functions instead, where possible.) #[allow(rustc::usage_of_ty_tykind)] #[inline(never)] fn intern_ty(&self, kind: TyKind<'tcx>, sess: &Session, untracked: &Untracked) -> Ty<'tcx> { Ty(Interned::new_unchecked( self.type_ .intern(kind, |kind| { let flags = super::flags::FlagComputation::for_kind(&kind); let stable_hash = self.stable_hash(&flags, sess, untracked, &kind); InternedInSet(self.arena.alloc(WithCachedTypeInfo { internee: kind, stable_hash, flags: flags.flags, outer_exclusive_binder: flags.outer_exclusive_binder, })) }) .0, )) } fn stable_hash<'a, T: HashStable>>( &self, flags: &ty::flags::FlagComputation, sess: &'a Session, untracked: &'a Untracked, val: &T, ) -> Fingerprint { // It's impossible to hash inference variables (and will ICE), so we don't need to try to cache them. // Without incremental, we rarely stable-hash types, so let's not do it proactively. if flags.flags.intersects(TypeFlags::HAS_INFER) || sess.opts.incremental.is_none() { Fingerprint::ZERO } else { let mut hasher = StableHasher::new(); let mut hcx = StableHashingContext::new(sess, untracked); val.hash_stable(&mut hcx, &mut hasher); hasher.finish() } } /// Interns a predicate. (Use `mk_predicate` instead, where possible.) #[inline(never)] fn intern_predicate( &self, kind: Binder<'tcx, PredicateKind<'tcx>>, sess: &Session, untracked: &Untracked, ) -> Predicate<'tcx> { Predicate(Interned::new_unchecked( self.predicate .intern(kind, |kind| { let flags = super::flags::FlagComputation::for_predicate(kind); let stable_hash = self.stable_hash(&flags, sess, untracked, &kind); InternedInSet(self.arena.alloc(WithCachedTypeInfo { internee: kind, stable_hash, flags: flags.flags, outer_exclusive_binder: flags.outer_exclusive_binder, })) }) .0, )) } } // For these preinterned values, an alternative would be to have // variable-length vectors that grow as needed. But that turned out to be // slightly more complex and no faster. const NUM_PREINTERNED_TY_VARS: u32 = 100; const NUM_PREINTERNED_FRESH_TYS: u32 = 20; const NUM_PREINTERNED_FRESH_INT_TYS: u32 = 3; const NUM_PREINTERNED_FRESH_FLOAT_TYS: u32 = 3; // This number may seem high, but it is reached in all but the smallest crates. const NUM_PREINTERNED_RE_VARS: u32 = 500; const NUM_PREINTERNED_RE_LATE_BOUNDS_I: u32 = 2; const NUM_PREINTERNED_RE_LATE_BOUNDS_V: u32 = 20; pub struct CommonTypes<'tcx> { pub unit: Ty<'tcx>, pub bool: Ty<'tcx>, pub char: Ty<'tcx>, pub isize: Ty<'tcx>, pub i8: Ty<'tcx>, pub i16: Ty<'tcx>, pub i32: Ty<'tcx>, pub i64: Ty<'tcx>, pub i128: Ty<'tcx>, pub usize: Ty<'tcx>, pub u8: Ty<'tcx>, pub u16: Ty<'tcx>, pub u32: Ty<'tcx>, pub u64: Ty<'tcx>, pub u128: Ty<'tcx>, pub f32: Ty<'tcx>, pub f64: Ty<'tcx>, pub str_: Ty<'tcx>, pub never: Ty<'tcx>, pub self_param: Ty<'tcx>, /// Dummy type used for the `Self` of a `TraitRef` created for converting /// a trait object, and which gets removed in `ExistentialTraitRef`. /// This type must not appear anywhere in other converted types. /// `Infer(ty::FreshTy(0))` does the job. pub trait_object_dummy_self: Ty<'tcx>, /// Pre-interned `Infer(ty::TyVar(n))` for small values of `n`. pub ty_vars: Vec>, /// Pre-interned `Infer(ty::FreshTy(n))` for small values of `n`. pub fresh_tys: Vec>, /// Pre-interned `Infer(ty::FreshIntTy(n))` for small values of `n`. pub fresh_int_tys: Vec>, /// Pre-interned `Infer(ty::FreshFloatTy(n))` for small values of `n`. pub fresh_float_tys: Vec>, } pub struct CommonLifetimes<'tcx> { /// `ReStatic` pub re_static: Region<'tcx>, /// Erased region, used outside of type inference. pub re_erased: Region<'tcx>, /// Pre-interned `ReVar(ty::RegionVar(n))` for small values of `n`. pub re_vars: Vec>, /// Pre-interned values of the form: /// `ReLateBound(DebruijnIndex(i), BoundRegion { var: v, kind: BrAnon(None) })` /// for small values of `i` and `v`. pub re_late_bounds: Vec>>, } pub struct CommonConsts<'tcx> { pub unit: Const<'tcx>, pub true_: Const<'tcx>, pub false_: Const<'tcx>, } impl<'tcx> CommonTypes<'tcx> { fn new( interners: &CtxtInterners<'tcx>, sess: &Session, untracked: &Untracked, ) -> CommonTypes<'tcx> { let mk = |ty| interners.intern_ty(ty, sess, untracked); let ty_vars = (0..NUM_PREINTERNED_TY_VARS).map(|n| mk(Infer(ty::TyVar(TyVid::from(n))))).collect(); let fresh_tys: Vec<_> = (0..NUM_PREINTERNED_FRESH_TYS).map(|n| mk(Infer(ty::FreshTy(n)))).collect(); let fresh_int_tys: Vec<_> = (0..NUM_PREINTERNED_FRESH_INT_TYS).map(|n| mk(Infer(ty::FreshIntTy(n)))).collect(); let fresh_float_tys: Vec<_> = (0..NUM_PREINTERNED_FRESH_FLOAT_TYS).map(|n| mk(Infer(ty::FreshFloatTy(n)))).collect(); CommonTypes { unit: mk(Tuple(List::empty())), bool: mk(Bool), char: mk(Char), never: mk(Never), isize: mk(Int(ty::IntTy::Isize)), i8: mk(Int(ty::IntTy::I8)), i16: mk(Int(ty::IntTy::I16)), i32: mk(Int(ty::IntTy::I32)), i64: mk(Int(ty::IntTy::I64)), i128: mk(Int(ty::IntTy::I128)), usize: mk(Uint(ty::UintTy::Usize)), u8: mk(Uint(ty::UintTy::U8)), u16: mk(Uint(ty::UintTy::U16)), u32: mk(Uint(ty::UintTy::U32)), u64: mk(Uint(ty::UintTy::U64)), u128: mk(Uint(ty::UintTy::U128)), f32: mk(Float(ty::FloatTy::F32)), f64: mk(Float(ty::FloatTy::F64)), str_: mk(Str), self_param: mk(ty::Param(ty::ParamTy { index: 0, name: kw::SelfUpper })), trait_object_dummy_self: fresh_tys[0], ty_vars, fresh_tys, fresh_int_tys, fresh_float_tys, } } } impl<'tcx> CommonLifetimes<'tcx> { fn new(interners: &CtxtInterners<'tcx>) -> CommonLifetimes<'tcx> { let mk = |r| { Region(Interned::new_unchecked( interners.region.intern(r, |r| InternedInSet(interners.arena.alloc(r))).0, )) }; let re_vars = (0..NUM_PREINTERNED_RE_VARS).map(|n| mk(ty::ReVar(ty::RegionVid::from(n)))).collect(); let re_late_bounds = (0..NUM_PREINTERNED_RE_LATE_BOUNDS_I) .map(|i| { (0..NUM_PREINTERNED_RE_LATE_BOUNDS_V) .map(|v| { mk(ty::ReLateBound( ty::DebruijnIndex::from(i), ty::BoundRegion { var: ty::BoundVar::from(v), kind: ty::BrAnon(None) }, )) }) .collect() }) .collect(); CommonLifetimes { re_static: mk(ty::ReStatic), re_erased: mk(ty::ReErased), re_vars, re_late_bounds, } } } impl<'tcx> CommonConsts<'tcx> { fn new(interners: &CtxtInterners<'tcx>, types: &CommonTypes<'tcx>) -> CommonConsts<'tcx> { let mk_const = |c| { Const(Interned::new_unchecked( interners.const_.intern(c, |c| InternedInSet(interners.arena.alloc(c))).0, )) }; CommonConsts { unit: mk_const(ty::ConstData { kind: ty::ConstKind::Value(ty::ValTree::zst()), ty: types.unit, }), true_: mk_const(ty::ConstData { kind: ty::ConstKind::Value(ty::ValTree::Leaf(ty::ScalarInt::TRUE)), ty: types.bool, }), false_: mk_const(ty::ConstData { kind: ty::ConstKind::Value(ty::ValTree::Leaf(ty::ScalarInt::FALSE)), ty: types.bool, }), } } } /// This struct contains information regarding the `ReFree(FreeRegion)` corresponding to a lifetime /// conflict. #[derive(Debug)] pub struct FreeRegionInfo { /// `LocalDefId` corresponding to FreeRegion pub def_id: LocalDefId, /// the bound region corresponding to FreeRegion pub boundregion: ty::BoundRegionKind, /// checks if bound region is in Impl Item pub is_impl_item: bool, } /// This struct should only be created by `create_def`. #[derive(Copy, Clone)] pub struct TyCtxtFeed<'tcx, KEY: Copy> { pub tcx: TyCtxt<'tcx>, // Do not allow direct access, as downstream code must not mutate this field. key: KEY, } impl<'tcx> TyCtxt<'tcx> { pub fn feed_unit_query(self) -> TyCtxtFeed<'tcx, ()> { TyCtxtFeed { tcx: self, key: () } } pub fn feed_local_crate(self) -> TyCtxtFeed<'tcx, CrateNum> { TyCtxtFeed { tcx: self, key: LOCAL_CRATE } } /// In order to break cycles involving `AnonConst`, we need to set the expected type by side /// effect. However, we do not want this as a general capability, so this interface restricts /// to the only allowed case. pub fn feed_anon_const_type(self, key: LocalDefId, value: ty::EarlyBinder>) { debug_assert_eq!(self.def_kind(key), DefKind::AnonConst); TyCtxtFeed { tcx: self, key }.type_of(value) } } impl<'tcx, KEY: Copy> TyCtxtFeed<'tcx, KEY> { #[inline(always)] pub fn key(&self) -> KEY { self.key } } impl<'tcx> TyCtxtFeed<'tcx, LocalDefId> { #[inline(always)] pub fn def_id(&self) -> LocalDefId { self.key } } /// The central data structure of the compiler. It stores references /// to the various **arenas** and also houses the results of the /// various **compiler queries** that have been performed. See the /// [rustc dev guide] for more details. /// /// [rustc dev guide]: https://rustc-dev-guide.rust-lang.org/ty.html /// /// An implementation detail: `TyCtxt` is a wrapper type for [GlobalCtxt], /// which is the struct that actually holds all the data. `TyCtxt` derefs to /// `GlobalCtxt`, and in practice `TyCtxt` is passed around everywhere, and all /// operations are done via `TyCtxt`. A `TyCtxt` is obtained for a `GlobalCtxt` /// by calling `enter` with a closure `f`. That function creates both the /// `TyCtxt`, and an `ImplicitCtxt` around it that is put into TLS. Within `f`: /// - The `ImplicitCtxt` is available implicitly via TLS. /// - The `TyCtxt` is available explicitly via the `tcx` parameter, and also /// implicitly within the `ImplicitCtxt`. Explicit access is preferred when /// possible. #[derive(Copy, Clone)] #[rustc_diagnostic_item = "TyCtxt"] #[rustc_pass_by_value] pub struct TyCtxt<'tcx> { gcx: &'tcx GlobalCtxt<'tcx>, } impl<'tcx> Deref for TyCtxt<'tcx> { type Target = &'tcx GlobalCtxt<'tcx>; #[inline(always)] fn deref(&self) -> &Self::Target { &self.gcx } } /// See [TyCtxt] for details about this type. pub struct GlobalCtxt<'tcx> { pub arena: &'tcx WorkerLocal>, pub hir_arena: &'tcx WorkerLocal>, interners: CtxtInterners<'tcx>, pub sess: &'tcx Session, /// This only ever stores a `LintStore` but we don't want a dependency on that type here. /// /// FIXME(Centril): consider `dyn LintStoreMarker` once /// we can upcast to `Any` for some additional type safety. pub lint_store: Lrc, pub dep_graph: DepGraph, pub prof: SelfProfilerRef, /// Common types, pre-interned for your convenience. pub types: CommonTypes<'tcx>, /// Common lifetimes, pre-interned for your convenience. pub lifetimes: CommonLifetimes<'tcx>, /// Common consts, pre-interned for your convenience. pub consts: CommonConsts<'tcx>, untracked: Untracked, pub query_system: QuerySystem<'tcx>, pub(crate) query_kinds: &'tcx [DepKindStruct<'tcx>], // Internal caches for metadata decoding. No need to track deps on this. pub ty_rcache: Lock>>, pub pred_rcache: Lock>>, /// Caches the results of trait selection. This cache is used /// for things that do not have to do with the parameters in scope. pub selection_cache: traits::SelectionCache<'tcx>, /// Caches the results of trait evaluation. This cache is used /// for things that do not have to do with the parameters in scope. /// Merge this with `selection_cache`? pub evaluation_cache: traits::EvaluationCache<'tcx>, /// Caches the results of goal evaluation in the new solver. pub new_solver_evaluation_cache: solve::EvaluationCache<'tcx>, /// Data layout specification for the current target. pub data_layout: TargetDataLayout, /// Stores memory for globals (statics/consts). pub(crate) alloc_map: Lock>, } impl<'tcx> GlobalCtxt<'tcx> { /// Installs `self` in a `TyCtxt` and `ImplicitCtxt` for the duration of /// `f`. pub fn enter<'a: 'tcx, F, R>(&'a self, f: F) -> R where F: FnOnce(TyCtxt<'tcx>) -> R, { let icx = tls::ImplicitCtxt::new(self); tls::enter_context(&icx, || f(icx.tcx)) } } impl<'tcx> TyCtxt<'tcx> { /// Expects a body and returns its codegen attributes. /// /// Unlike `codegen_fn_attrs`, this returns `CodegenFnAttrs::EMPTY` for /// constants. pub fn body_codegen_attrs(self, def_id: DefId) -> &'tcx CodegenFnAttrs { let def_kind = self.def_kind(def_id); if def_kind.has_codegen_attrs() { self.codegen_fn_attrs(def_id) } else if matches!( def_kind, DefKind::AnonConst | DefKind::AssocConst | DefKind::Const | DefKind::InlineConst ) { CodegenFnAttrs::EMPTY } else { bug!( "body_codegen_fn_attrs called on unexpected definition: {:?} {:?}", def_id, def_kind ) } } pub fn alloc_steal_thir(self, thir: Thir<'tcx>) -> &'tcx Steal> { self.arena.alloc(Steal::new(thir)) } pub fn alloc_steal_mir(self, mir: Body<'tcx>) -> &'tcx Steal> { self.arena.alloc(Steal::new(mir)) } pub fn alloc_steal_promoted( self, promoted: IndexVec>, ) -> &'tcx Steal>> { self.arena.alloc(Steal::new(promoted)) } pub fn mk_adt_def( self, did: DefId, kind: AdtKind, variants: IndexVec, repr: ReprOptions, ) -> ty::AdtDef<'tcx> { self.mk_adt_def_from_data(ty::AdtDefData::new(self, did, kind, variants, repr)) } /// Allocates a read-only byte or string literal for `mir::interpret`. pub fn allocate_bytes(self, bytes: &[u8]) -> interpret::AllocId { // Create an allocation that just contains these bytes. let alloc = interpret::Allocation::from_bytes_byte_aligned_immutable(bytes); let alloc = self.mk_const_alloc(alloc); self.create_memory_alloc(alloc) } /// Returns a range of the start/end indices specified with the /// `rustc_layout_scalar_valid_range` attribute. // FIXME(eddyb) this is an awkward spot for this method, maybe move it? pub fn layout_scalar_valid_range(self, def_id: DefId) -> (Bound, Bound) { let get = |name| { let Some(attr) = self.get_attr(def_id, name) else { return Bound::Unbounded; }; debug!("layout_scalar_valid_range: attr={:?}", attr); if let Some( &[ ast::NestedMetaItem::Lit(ast::MetaItemLit { kind: ast::LitKind::Int(a, _), .. }), ], ) = attr.meta_item_list().as_deref() { Bound::Included(a) } else { self.sess .delay_span_bug(attr.span, "invalid rustc_layout_scalar_valid_range attribute"); Bound::Unbounded } }; ( get(sym::rustc_layout_scalar_valid_range_start), get(sym::rustc_layout_scalar_valid_range_end), ) } pub fn lift>(self, value: T) -> Option { value.lift_to_tcx(self) } /// Creates a type context and call the closure with a `TyCtxt` reference /// to the context. The closure enforces that the type context and any interned /// value (types, substs, etc.) can only be used while `ty::tls` has a valid /// reference to the context, to allow formatting values that need it. pub fn create_global_ctxt( s: &'tcx Session, lint_store: Lrc, arena: &'tcx WorkerLocal>, hir_arena: &'tcx WorkerLocal>, untracked: Untracked, dep_graph: DepGraph, query_kinds: &'tcx [DepKindStruct<'tcx>], query_system: QuerySystem<'tcx>, ) -> GlobalCtxt<'tcx> { let data_layout = s.target.parse_data_layout().unwrap_or_else(|err| { s.emit_fatal(err); }); let interners = CtxtInterners::new(arena); let common_types = CommonTypes::new(&interners, s, &untracked); let common_lifetimes = CommonLifetimes::new(&interners); let common_consts = CommonConsts::new(&interners, &common_types); GlobalCtxt { sess: s, lint_store, arena, hir_arena, interners, dep_graph, prof: s.prof.clone(), types: common_types, lifetimes: common_lifetimes, consts: common_consts, untracked, query_system, query_kinds, ty_rcache: Default::default(), pred_rcache: Default::default(), selection_cache: Default::default(), evaluation_cache: Default::default(), new_solver_evaluation_cache: Default::default(), data_layout, alloc_map: Lock::new(interpret::AllocMap::new()), } } pub fn consider_optimizing String>(self, msg: T) -> bool { self.sess.consider_optimizing(|| self.crate_name(LOCAL_CRATE), msg) } /// Obtain all lang items of this crate and all dependencies (recursively) pub fn lang_items(self) -> &'tcx rustc_hir::lang_items::LanguageItems { self.get_lang_items(()) } /// Obtain the given diagnostic item's `DefId`. Use `is_diagnostic_item` if you just want to /// compare against another `DefId`, since `is_diagnostic_item` is cheaper. pub fn get_diagnostic_item(self, name: Symbol) -> Option { self.all_diagnostic_items(()).name_to_id.get(&name).copied() } /// Obtain the diagnostic item's name pub fn get_diagnostic_name(self, id: DefId) -> Option { self.diagnostic_items(id.krate).id_to_name.get(&id).copied() } /// Check whether the diagnostic item with the given `name` has the given `DefId`. pub fn is_diagnostic_item(self, name: Symbol, did: DefId) -> bool { self.diagnostic_items(did.krate).name_to_id.get(&name) == Some(&did) } /// Returns `true` if the node pointed to by `def_id` is a generator for an async construct. pub fn generator_is_async(self, def_id: DefId) -> bool { matches!(self.generator_kind(def_id), Some(hir::GeneratorKind::Async(_))) } pub fn stability(self) -> &'tcx stability::Index { self.stability_index(()) } pub fn features(self) -> &'tcx rustc_feature::Features { self.features_query(()) } pub fn def_key(self, id: impl IntoQueryParam) -> rustc_hir::definitions::DefKey { let id = id.into_query_param(); // Accessing the DefKey is ok, since it is part of DefPathHash. if let Some(id) = id.as_local() { self.definitions_untracked().def_key(id) } else { self.cstore_untracked().def_key(id) } } /// Converts a `DefId` into its fully expanded `DefPath` (every /// `DefId` is really just an interned `DefPath`). /// /// Note that if `id` is not local to this crate, the result will /// be a non-local `DefPath`. pub fn def_path(self, id: DefId) -> rustc_hir::definitions::DefPath { // Accessing the DefPath is ok, since it is part of DefPathHash. if let Some(id) = id.as_local() { self.definitions_untracked().def_path(id) } else { self.cstore_untracked().def_path(id) } } #[inline] pub fn def_path_hash(self, def_id: DefId) -> rustc_hir::definitions::DefPathHash { // Accessing the DefPathHash is ok, it is incr. comp. stable. if let Some(def_id) = def_id.as_local() { self.definitions_untracked().def_path_hash(def_id) } else { self.cstore_untracked().def_path_hash(def_id) } } #[inline] pub fn stable_crate_id(self, crate_num: CrateNum) -> StableCrateId { if crate_num == LOCAL_CRATE { self.sess.local_stable_crate_id() } else { self.cstore_untracked().stable_crate_id(crate_num) } } /// Maps a StableCrateId to the corresponding CrateNum. This method assumes /// that the crate in question has already been loaded by the CrateStore. #[inline] pub fn stable_crate_id_to_crate_num(self, stable_crate_id: StableCrateId) -> CrateNum { if stable_crate_id == self.sess.local_stable_crate_id() { LOCAL_CRATE } else { self.cstore_untracked().stable_crate_id_to_crate_num(stable_crate_id) } } /// Converts a `DefPathHash` to its corresponding `DefId` in the current compilation /// session, if it still exists. This is used during incremental compilation to /// turn a deserialized `DefPathHash` into its current `DefId`. pub fn def_path_hash_to_def_id(self, hash: DefPathHash, err: &mut dyn FnMut() -> !) -> DefId { debug!("def_path_hash_to_def_id({:?})", hash); let stable_crate_id = hash.stable_crate_id(); // If this is a DefPathHash from the local crate, we can look up the // DefId in the tcx's `Definitions`. if stable_crate_id == self.sess.local_stable_crate_id() { self.untracked.definitions.read().local_def_path_hash_to_def_id(hash, err).to_def_id() } else { // If this is a DefPathHash from an upstream crate, let the CrateStore map // it to a DefId. let cstore = &*self.cstore_untracked(); let cnum = cstore.stable_crate_id_to_crate_num(stable_crate_id); cstore.def_path_hash_to_def_id(cnum, hash) } } pub fn def_path_debug_str(self, def_id: DefId) -> String { // We are explicitly not going through queries here in order to get // crate name and stable crate id since this code is called from debug!() // statements within the query system and we'd run into endless // recursion otherwise. let (crate_name, stable_crate_id) = if def_id.is_local() { (self.crate_name(LOCAL_CRATE), self.sess.local_stable_crate_id()) } else { let cstore = &*self.cstore_untracked(); (cstore.crate_name(def_id.krate), cstore.stable_crate_id(def_id.krate)) }; format!( "{}[{:04x}]{}", crate_name, // Don't print the whole stable crate id. That's just // annoying in debug output. stable_crate_id.as_u64() >> (8 * 6), self.def_path(def_id).to_string_no_crate_verbose() ) } } impl<'tcx> TyCtxtAt<'tcx> { /// Create a new definition within the incr. comp. engine. pub fn create_def( self, parent: LocalDefId, data: hir::definitions::DefPathData, ) -> TyCtxtFeed<'tcx, LocalDefId> { // This function modifies `self.definitions` using a side-effect. // We need to ensure that these side effects are re-run by the incr. comp. engine. // Depending on the forever-red node will tell the graph that the calling query // needs to be re-evaluated. self.dep_graph.read_index(DepNodeIndex::FOREVER_RED_NODE); // The following call has the side effect of modifying the tables inside `definitions`. // These very tables are relied on by the incr. comp. engine to decode DepNodes and to // decode the on-disk cache. // // Any LocalDefId which is used within queries, either as key or result, either: // - has been created before the construction of the TyCtxt; // - has been created by this call to `create_def`. // As a consequence, this LocalDefId is always re-created before it is needed by the incr. // comp. engine itself. // // This call also writes to the value of `source_span` and `expn_that_defined` queries. // This is fine because: // - those queries are `eval_always` so we won't miss their result changing; // - this write will have happened before these queries are called. let key = self.untracked.definitions.write().create_def(parent, data); let feed = TyCtxtFeed { tcx: self.tcx, key }; feed.def_span(self.span); feed } } impl<'tcx> TyCtxt<'tcx> { pub fn iter_local_def_id(self) -> impl Iterator + 'tcx { // Create a dependency to the red node to be sure we re-execute this when the amount of // definitions change. self.dep_graph.read_index(DepNodeIndex::FOREVER_RED_NODE); let definitions = &self.untracked.definitions; std::iter::from_generator(|| { let mut i = 0; // Recompute the number of definitions each time, because our caller may be creating // new ones. while i < { definitions.read().num_definitions() } { let local_def_index = rustc_span::def_id::DefIndex::from_usize(i); yield LocalDefId { local_def_index }; i += 1; } // Leak a read lock once we finish iterating on definitions, to prevent adding new ones. definitions.leak(); }) } pub fn def_path_table(self) -> &'tcx rustc_hir::definitions::DefPathTable { // Create a dependency to the crate to be sure we re-execute this when the amount of // definitions change. self.dep_graph.read_index(DepNodeIndex::FOREVER_RED_NODE); // Leak a read lock once we start iterating on definitions, to prevent adding new ones // while iterating. If some query needs to add definitions, it should be `ensure`d above. let definitions = self.untracked.definitions.leak(); definitions.def_path_table() } pub fn def_path_hash_to_def_index_map( self, ) -> &'tcx rustc_hir::def_path_hash_map::DefPathHashMap { // Create a dependency to the crate to be sure we re-execute this when the amount of // definitions change. self.ensure().hir_crate(()); // Leak a read lock once we start iterating on definitions, to prevent adding new ones // while iterating. If some query needs to add definitions, it should be `ensure`d above. let definitions = self.untracked.definitions.leak(); definitions.def_path_hash_to_def_index_map() } /// Note that this is *untracked* and should only be used within the query /// system if the result is otherwise tracked through queries #[inline] pub fn cstore_untracked(self) -> MappedReadGuard<'tcx, CrateStoreDyn> { ReadGuard::map(self.untracked.cstore.read(), |c| &**c) } /// Give out access to the untracked data without any sanity checks. pub fn untracked(self) -> &'tcx Untracked { &self.untracked } /// Note that this is *untracked* and should only be used within the query /// system if the result is otherwise tracked through queries #[inline] pub fn definitions_untracked(self) -> ReadGuard<'tcx, Definitions> { self.untracked.definitions.read() } /// Note that this is *untracked* and should only be used within the query /// system if the result is otherwise tracked through queries #[inline] pub fn source_span_untracked(self, def_id: LocalDefId) -> Span { self.untracked.source_span.get(def_id).unwrap_or(DUMMY_SP) } #[inline(always)] pub fn with_stable_hashing_context( self, f: impl FnOnce(StableHashingContext<'_>) -> R, ) -> R { f(StableHashingContext::new(self.sess, &self.untracked)) } pub fn serialize_query_result_cache(self, encoder: FileEncoder) -> FileEncodeResult { self.query_system.on_disk_cache.as_ref().map_or(Ok(0), |c| c.serialize(self, encoder)) } #[inline] pub fn local_crate_exports_generics(self) -> bool { debug_assert!(self.sess.opts.share_generics()); self.sess.crate_types().iter().any(|crate_type| { match crate_type { CrateType::Executable | CrateType::Staticlib | CrateType::ProcMacro | CrateType::Cdylib => false, // FIXME rust-lang/rust#64319, rust-lang/rust#64872: // We want to block export of generics from dylibs, // but we must fix rust-lang/rust#65890 before we can // do that robustly. CrateType::Dylib => true, CrateType::Rlib => true, } }) } /// Returns the `DefId` and the `BoundRegionKind` corresponding to the given region. pub fn is_suitable_region(self, region: Region<'tcx>) -> Option { let (suitable_region_binding_scope, bound_region) = match *region { ty::ReFree(ref free_region) => { (free_region.scope.expect_local(), free_region.bound_region) } ty::ReEarlyBound(ref ebr) => ( self.local_parent(ebr.def_id.expect_local()), ty::BoundRegionKind::BrNamed(ebr.def_id, ebr.name), ), _ => return None, // not a free region }; let is_impl_item = match self.hir().find_by_def_id(suitable_region_binding_scope) { Some(Node::Item(..) | Node::TraitItem(..)) => false, Some(Node::ImplItem(..)) => { self.is_bound_region_in_impl_item(suitable_region_binding_scope) } _ => return None, }; Some(FreeRegionInfo { def_id: suitable_region_binding_scope, boundregion: bound_region, is_impl_item, }) } /// Given a `DefId` for an `fn`, return all the `dyn` and `impl` traits in its return type. pub fn return_type_impl_or_dyn_traits( self, scope_def_id: LocalDefId, ) -> Vec<&'tcx hir::Ty<'tcx>> { let hir_id = self.hir().local_def_id_to_hir_id(scope_def_id); let Some(hir::FnDecl { output: hir::FnRetTy::Return(hir_output), .. }) = self.hir().fn_decl_by_hir_id(hir_id) else { return vec![]; }; let mut v = TraitObjectVisitor(vec![], self.hir()); v.visit_ty(hir_output); v.0 } /// Given a `DefId` for an `fn`, return all the `dyn` and `impl` traits in /// its return type, and the associated alias span when type alias is used, /// along with a span for lifetime suggestion (if there are existing generics). pub fn return_type_impl_or_dyn_traits_with_type_alias( self, scope_def_id: LocalDefId, ) -> Option<(Vec<&'tcx hir::Ty<'tcx>>, Span, Option)> { let hir_id = self.hir().local_def_id_to_hir_id(scope_def_id); let mut v = TraitObjectVisitor(vec![], self.hir()); // when the return type is a type alias if let Some(hir::FnDecl { output: hir::FnRetTy::Return(hir_output), .. }) = self.hir().fn_decl_by_hir_id(hir_id) && let hir::TyKind::Path(hir::QPath::Resolved( None, hir::Path { res: hir::def::Res::Def(DefKind::TyAlias, def_id), .. }, )) = hir_output.kind && let Some(local_id) = def_id.as_local() && let Some(alias_ty) = self.hir().get_by_def_id(local_id).alias_ty() // it is type alias && let Some(alias_generics) = self.hir().get_by_def_id(local_id).generics() { v.visit_ty(alias_ty); if !v.0.is_empty() { return Some((v.0, alias_generics.span, alias_generics.span_for_lifetime_suggestion())); } } return None; } pub fn return_type_impl_trait(self, scope_def_id: LocalDefId) -> Option<(Ty<'tcx>, Span)> { // `type_of()` will fail on these (#55796, #86483), so only allow `fn`s or closures. match self.hir().get_by_def_id(scope_def_id) { Node::Item(&hir::Item { kind: ItemKind::Fn(..), .. }) => {} Node::TraitItem(&hir::TraitItem { kind: TraitItemKind::Fn(..), .. }) => {} Node::ImplItem(&hir::ImplItem { kind: ImplItemKind::Fn(..), .. }) => {} Node::Expr(&hir::Expr { kind: ExprKind::Closure { .. }, .. }) => {} _ => return None, } let ret_ty = self.type_of(scope_def_id).subst_identity(); match ret_ty.kind() { ty::FnDef(_, _) => { let sig = ret_ty.fn_sig(self); let output = self.erase_late_bound_regions(sig.output()); output.is_impl_trait().then(|| { let hir_id = self.hir().local_def_id_to_hir_id(scope_def_id); let fn_decl = self.hir().fn_decl_by_hir_id(hir_id).unwrap(); (output, fn_decl.output.span()) }) } _ => None, } } /// Checks if the bound region is in Impl Item. pub fn is_bound_region_in_impl_item(self, suitable_region_binding_scope: LocalDefId) -> bool { let container_id = self.parent(suitable_region_binding_scope.to_def_id()); if self.impl_trait_ref(container_id).is_some() { // For now, we do not try to target impls of traits. This is // because this message is going to suggest that the user // change the fn signature, but they may not be free to do so, // since the signature must match the trait. // // FIXME(#42706) -- in some cases, we could do better here. return true; } false } /// Determines whether identifiers in the assembly have strict naming rules. /// Currently, only NVPTX* targets need it. pub fn has_strict_asm_symbol_naming(self) -> bool { self.sess.target.arch.contains("nvptx") } /// Returns `&'static core::panic::Location<'static>`. pub fn caller_location_ty(self) -> Ty<'tcx> { Ty::new_imm_ref( self, self.lifetimes.re_static, self.type_of(self.require_lang_item(LangItem::PanicLocation, None)) .subst(self, self.mk_substs(&[self.lifetimes.re_static.into()])), ) } /// Returns a displayable description and article for the given `def_id` (e.g. `("a", "struct")`). pub fn article_and_description(self, def_id: DefId) -> (&'static str, &'static str) { let kind = self.def_kind(def_id); (self.def_kind_descr_article(kind, def_id), self.def_kind_descr(kind, def_id)) } pub fn type_length_limit(self) -> Limit { self.limits(()).type_length_limit } pub fn recursion_limit(self) -> Limit { self.limits(()).recursion_limit } pub fn move_size_limit(self) -> Limit { self.limits(()).move_size_limit } pub fn all_traits(self) -> impl Iterator + 'tcx { iter::once(LOCAL_CRATE) .chain(self.crates(()).iter().copied()) .flat_map(move |cnum| self.traits(cnum).iter().copied()) } #[inline] pub fn local_visibility(self, def_id: LocalDefId) -> Visibility { self.visibility(def_id).expect_local() } /// Returns the origin of the opaque type `def_id`. #[instrument(skip(self), level = "trace", ret)] pub fn opaque_type_origin(self, def_id: LocalDefId) -> hir::OpaqueTyOrigin { self.hir().expect_item(def_id).expect_opaque_ty().origin } } /// A trait implemented for all `X<'a>` types that can be safely and /// efficiently converted to `X<'tcx>` as long as they are part of the /// provided `TyCtxt<'tcx>`. /// This can be done, for example, for `Ty<'tcx>` or `SubstsRef<'tcx>` /// by looking them up in their respective interners. /// /// However, this is still not the best implementation as it does /// need to compare the components, even for interned values. /// It would be more efficient if `TypedArena` provided a way to /// determine whether the address is in the allocated range. /// /// `None` is returned if the value or one of the components is not part /// of the provided context. /// For `Ty`, `None` can be returned if either the type interner doesn't /// contain the `TyKind` key or if the address of the interned /// pointer differs. The latter case is possible if a primitive type, /// e.g., `()` or `u8`, was interned in a different context. pub trait Lift<'tcx>: fmt::Debug { type Lifted: fmt::Debug + 'tcx; fn lift_to_tcx(self, tcx: TyCtxt<'tcx>) -> Option; } macro_rules! nop_lift { ($set:ident; $ty:ty => $lifted:ty) => { impl<'a, 'tcx> Lift<'tcx> for $ty { type Lifted = $lifted; fn lift_to_tcx(self, tcx: TyCtxt<'tcx>) -> Option { tcx.interners .$set .contains_pointer_to(&InternedInSet(&*self.0.0)) // SAFETY: `self` is interned and therefore valid // for the entire lifetime of the `TyCtxt`. .then(|| unsafe { mem::transmute(self) }) } } }; } macro_rules! nop_list_lift { ($set:ident; $ty:ty => $lifted:ty) => { impl<'a, 'tcx> Lift<'tcx> for &'a List<$ty> { type Lifted = &'tcx List<$lifted>; fn lift_to_tcx(self, tcx: TyCtxt<'tcx>) -> Option { if self.is_empty() { return Some(List::empty()); } tcx.interners .$set .contains_pointer_to(&InternedInSet(self)) .then(|| unsafe { mem::transmute(self) }) } } }; } nop_lift! {type_; Ty<'a> => Ty<'tcx>} nop_lift! {region; Region<'a> => Region<'tcx>} nop_lift! {const_; Const<'a> => Const<'tcx>} nop_lift! {const_allocation; ConstAllocation<'a> => ConstAllocation<'tcx>} nop_lift! {predicate; Predicate<'a> => Predicate<'tcx>} nop_lift! {predicate; Clause<'a> => Clause<'tcx>} nop_list_lift! {type_lists; Ty<'a> => Ty<'tcx>} nop_list_lift! {poly_existential_predicates; PolyExistentialPredicate<'a> => PolyExistentialPredicate<'tcx>} nop_list_lift! {clauses; Clause<'a> => Clause<'tcx>} nop_list_lift! {canonical_var_infos; CanonicalVarInfo<'a> => CanonicalVarInfo<'tcx>} nop_list_lift! {projs; ProjectionKind => ProjectionKind} nop_list_lift! {bound_variable_kinds; ty::BoundVariableKind => ty::BoundVariableKind} // This is the impl for `&'a InternalSubsts<'a>`. nop_list_lift! {substs; GenericArg<'a> => GenericArg<'tcx>} CloneLiftImpls! { Constness, traits::WellFormedLoc, ImplPolarity, crate::mir::ReturnConstraint, } macro_rules! sty_debug_print { ($fmt: expr, $ctxt: expr, $($variant: ident),*) => {{ // Curious inner module to allow variant names to be used as // variable names. #[allow(non_snake_case)] mod inner { use crate::ty::{self, TyCtxt}; use crate::ty::context::InternedInSet; #[derive(Copy, Clone)] struct DebugStat { total: usize, lt_infer: usize, ty_infer: usize, ct_infer: usize, all_infer: usize, } pub fn go(fmt: &mut std::fmt::Formatter<'_>, tcx: TyCtxt<'_>) -> std::fmt::Result { let mut total = DebugStat { total: 0, lt_infer: 0, ty_infer: 0, ct_infer: 0, all_infer: 0, }; $(let mut $variant = total;)* let shards = tcx.interners.type_.lock_shards(); let types = shards.iter().flat_map(|shard| shard.keys()); for &InternedInSet(t) in types { let variant = match t.internee { ty::Bool | ty::Char | ty::Int(..) | ty::Uint(..) | ty::Float(..) | ty::Str | ty::Never => continue, ty::Error(_) => /* unimportant */ continue, $(ty::$variant(..) => &mut $variant,)* }; let lt = t.flags.intersects(ty::TypeFlags::HAS_RE_INFER); let ty = t.flags.intersects(ty::TypeFlags::HAS_TY_INFER); let ct = t.flags.intersects(ty::TypeFlags::HAS_CT_INFER); variant.total += 1; total.total += 1; if lt { total.lt_infer += 1; variant.lt_infer += 1 } if ty { total.ty_infer += 1; variant.ty_infer += 1 } if ct { total.ct_infer += 1; variant.ct_infer += 1 } if lt && ty && ct { total.all_infer += 1; variant.all_infer += 1 } } writeln!(fmt, "Ty interner total ty lt ct all")?; $(writeln!(fmt, " {:18}: {uses:6} {usespc:4.1}%, \ {ty:4.1}% {lt:5.1}% {ct:4.1}% {all:4.1}%", stringify!($variant), uses = $variant.total, usespc = $variant.total as f64 * 100.0 / total.total as f64, ty = $variant.ty_infer as f64 * 100.0 / total.total as f64, lt = $variant.lt_infer as f64 * 100.0 / total.total as f64, ct = $variant.ct_infer as f64 * 100.0 / total.total as f64, all = $variant.all_infer as f64 * 100.0 / total.total as f64)?; )* writeln!(fmt, " total {uses:6} \ {ty:4.1}% {lt:5.1}% {ct:4.1}% {all:4.1}%", uses = total.total, ty = total.ty_infer as f64 * 100.0 / total.total as f64, lt = total.lt_infer as f64 * 100.0 / total.total as f64, ct = total.ct_infer as f64 * 100.0 / total.total as f64, all = total.all_infer as f64 * 100.0 / total.total as f64) } } inner::go($fmt, $ctxt) }} } impl<'tcx> TyCtxt<'tcx> { pub fn debug_stats(self) -> impl std::fmt::Debug + 'tcx { struct DebugStats<'tcx>(TyCtxt<'tcx>); impl<'tcx> std::fmt::Debug for DebugStats<'tcx> { fn fmt(&self, fmt: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { sty_debug_print!( fmt, self.0, Adt, Array, Slice, RawPtr, Ref, FnDef, FnPtr, Placeholder, Generator, GeneratorWitness, GeneratorWitnessMIR, Dynamic, Closure, Tuple, Bound, Param, Infer, Alias, Foreign )?; writeln!(fmt, "InternalSubsts interner: #{}", self.0.interners.substs.len())?; writeln!(fmt, "Region interner: #{}", self.0.interners.region.len())?; writeln!( fmt, "Const Allocation interner: #{}", self.0.interners.const_allocation.len() )?; writeln!(fmt, "Layout interner: #{}", self.0.interners.layout.len())?; Ok(()) } } DebugStats(self) } } // This type holds a `T` in the interner. The `T` is stored in the arena and // this type just holds a pointer to it, but it still effectively owns it. It // impls `Borrow` so that it can be looked up using the original // (non-arena-memory-owning) types. struct InternedInSet<'tcx, T: ?Sized>(&'tcx T); impl<'tcx, T: 'tcx + ?Sized> Clone for InternedInSet<'tcx, T> { fn clone(&self) -> Self { InternedInSet(self.0) } } impl<'tcx, T: 'tcx + ?Sized> Copy for InternedInSet<'tcx, T> {} impl<'tcx, T: 'tcx + ?Sized> IntoPointer for InternedInSet<'tcx, T> { fn into_pointer(&self) -> *const () { self.0 as *const _ as *const () } } #[allow(rustc::usage_of_ty_tykind)] impl<'tcx, T> Borrow for InternedInSet<'tcx, WithCachedTypeInfo> { fn borrow(&self) -> &T { &self.0.internee } } impl<'tcx, T: PartialEq> PartialEq for InternedInSet<'tcx, WithCachedTypeInfo> { fn eq(&self, other: &InternedInSet<'tcx, WithCachedTypeInfo>) -> bool { // The `Borrow` trait requires that `x.borrow() == y.borrow()` equals // `x == y`. self.0.internee == other.0.internee } } impl<'tcx, T: Eq> Eq for InternedInSet<'tcx, WithCachedTypeInfo> {} impl<'tcx, T: Hash> Hash for InternedInSet<'tcx, WithCachedTypeInfo> { fn hash(&self, s: &mut H) { // The `Borrow` trait requires that `x.borrow().hash(s) == x.hash(s)`. self.0.internee.hash(s) } } impl<'tcx, T> Borrow<[T]> for InternedInSet<'tcx, List> { fn borrow(&self) -> &[T] { &self.0[..] } } impl<'tcx, T: PartialEq> PartialEq for InternedInSet<'tcx, List> { fn eq(&self, other: &InternedInSet<'tcx, List>) -> bool { // The `Borrow` trait requires that `x.borrow() == y.borrow()` equals // `x == y`. self.0[..] == other.0[..] } } impl<'tcx, T: Eq> Eq for InternedInSet<'tcx, List> {} impl<'tcx, T: Hash> Hash for InternedInSet<'tcx, List> { fn hash(&self, s: &mut H) { // The `Borrow` trait requires that `x.borrow().hash(s) == x.hash(s)`. self.0[..].hash(s) } } macro_rules! direct_interners { ($($name:ident: $vis:vis $method:ident($ty:ty): $ret_ctor:ident -> $ret_ty:ty,)+) => { $(impl<'tcx> Borrow<$ty> for InternedInSet<'tcx, $ty> { fn borrow<'a>(&'a self) -> &'a $ty { &self.0 } } impl<'tcx> PartialEq for InternedInSet<'tcx, $ty> { fn eq(&self, other: &Self) -> bool { // The `Borrow` trait requires that `x.borrow() == y.borrow()` // equals `x == y`. self.0 == other.0 } } impl<'tcx> Eq for InternedInSet<'tcx, $ty> {} impl<'tcx> Hash for InternedInSet<'tcx, $ty> { fn hash(&self, s: &mut H) { // The `Borrow` trait requires that `x.borrow().hash(s) == // x.hash(s)`. self.0.hash(s) } } impl<'tcx> TyCtxt<'tcx> { $vis fn $method(self, v: $ty) -> $ret_ty { $ret_ctor(Interned::new_unchecked(self.interners.$name.intern(v, |v| { InternedInSet(self.interners.arena.alloc(v)) }).0)) } })+ } } // Functions with a `mk_` prefix are intended for use outside this file and // crate. Functions with an `intern_` prefix are intended for use within this // crate only, and have a corresponding `mk_` function. direct_interners! { region: pub(crate) intern_region(RegionKind<'tcx>): Region -> Region<'tcx>, const_: intern_const(ConstData<'tcx>): Const -> Const<'tcx>, const_allocation: pub mk_const_alloc(Allocation): ConstAllocation -> ConstAllocation<'tcx>, layout: pub mk_layout(LayoutS): Layout -> Layout<'tcx>, adt_def: pub mk_adt_def_from_data(AdtDefData): AdtDef -> AdtDef<'tcx>, external_constraints: pub mk_external_constraints(ExternalConstraintsData<'tcx>): ExternalConstraints -> ExternalConstraints<'tcx>, predefined_opaques_in_body: pub mk_predefined_opaques_in_body(PredefinedOpaquesData<'tcx>): PredefinedOpaques -> PredefinedOpaques<'tcx>, } macro_rules! slice_interners { ($($field:ident: $vis:vis $method:ident($ty:ty)),+ $(,)?) => ( impl<'tcx> TyCtxt<'tcx> { $($vis fn $method(self, v: &[$ty]) -> &'tcx List<$ty> { if v.is_empty() { List::empty() } else { self.interners.$field.intern_ref(v, || { InternedInSet(List::from_arena(&*self.arena, v)) }).0 } })+ } ); } // These functions intern slices. They all have a corresponding // `mk_foo_from_iter` function that interns an iterator. The slice version // should be used when possible, because it's faster. slice_interners!( const_lists: pub mk_const_list(Const<'tcx>), substs: pub mk_substs(GenericArg<'tcx>), type_lists: pub mk_type_list(Ty<'tcx>), canonical_var_infos: pub mk_canonical_var_infos(CanonicalVarInfo<'tcx>), poly_existential_predicates: intern_poly_existential_predicates(PolyExistentialPredicate<'tcx>), clauses: intern_clauses(Clause<'tcx>), projs: pub mk_projs(ProjectionKind), place_elems: pub mk_place_elems(PlaceElem<'tcx>), bound_variable_kinds: pub mk_bound_variable_kinds(ty::BoundVariableKind), fields: pub mk_fields(FieldIdx), ); impl<'tcx> TyCtxt<'tcx> { /// Given a `fn` type, returns an equivalent `unsafe fn` type; /// that is, a `fn` type that is equivalent in every way for being /// unsafe. pub fn safe_to_unsafe_fn_ty(self, sig: PolyFnSig<'tcx>) -> Ty<'tcx> { assert_eq!(sig.unsafety(), hir::Unsafety::Normal); Ty::new_fn_ptr( self, sig.map_bound(|sig| ty::FnSig { unsafety: hir::Unsafety::Unsafe, ..sig }), ) } /// Given the def_id of a Trait `trait_def_id` and the name of an associated item `assoc_name` /// returns true if the `trait_def_id` defines an associated item of name `assoc_name`. pub fn trait_may_define_assoc_item(self, trait_def_id: DefId, assoc_name: Ident) -> bool { self.super_traits_of(trait_def_id).any(|trait_did| { self.associated_items(trait_did) .filter_by_name_unhygienic(assoc_name.name) .any(|item| self.hygienic_eq(assoc_name, item.ident(self), trait_did)) }) } /// Given a `ty`, return whether it's an `impl Future<...>`. pub fn ty_is_opaque_future(self, ty: Ty<'_>) -> bool { let ty::Alias(ty::Opaque, ty::AliasTy { def_id, .. }) = ty.kind() else { return false }; let future_trait = self.require_lang_item(LangItem::Future, None); self.explicit_item_bounds(def_id).skip_binder().iter().any(|&(predicate, _)| { let ty::ClauseKind::Trait(trait_predicate) = predicate.kind().skip_binder() else { return false; }; trait_predicate.trait_ref.def_id == future_trait && trait_predicate.polarity == ImplPolarity::Positive }) } /// Computes the def-ids of the transitive supertraits of `trait_def_id`. This (intentionally) /// does not compute the full elaborated super-predicates but just the set of def-ids. It is used /// to identify which traits may define a given associated type to help avoid cycle errors. /// Returns a `DefId` iterator. fn super_traits_of(self, trait_def_id: DefId) -> impl Iterator + 'tcx { let mut set = FxHashSet::default(); let mut stack = vec![trait_def_id]; set.insert(trait_def_id); iter::from_fn(move || -> Option { let trait_did = stack.pop()?; let generic_predicates = self.super_predicates_of(trait_did); for (predicate, _) in generic_predicates.predicates { if let ty::ClauseKind::Trait(data) = predicate.kind().skip_binder() { if set.insert(data.def_id()) { stack.push(data.def_id()); } } } Some(trait_did) }) } /// Given a closure signature, returns an equivalent fn signature. Detuples /// and so forth -- so e.g., if we have a sig with `Fn<(u32, i32)>` then /// you would get a `fn(u32, i32)`. /// `unsafety` determines the unsafety of the fn signature. If you pass /// `hir::Unsafety::Unsafe` in the previous example, then you would get /// an `unsafe fn (u32, i32)`. /// It cannot convert a closure that requires unsafe. pub fn signature_unclosure( self, sig: PolyFnSig<'tcx>, unsafety: hir::Unsafety, ) -> PolyFnSig<'tcx> { sig.map_bound(|s| { let params = match s.inputs()[0].kind() { ty::Tuple(params) => *params, _ => bug!(), }; self.mk_fn_sig(params, s.output(), s.c_variadic, unsafety, abi::Abi::Rust) }) } #[inline] pub fn mk_predicate(self, binder: Binder<'tcx, PredicateKind<'tcx>>) -> Predicate<'tcx> { self.interners.intern_predicate( binder, self.sess, // This is only used to create a stable hashing context. &self.untracked, ) } #[inline] pub fn reuse_or_mk_predicate( self, pred: Predicate<'tcx>, binder: Binder<'tcx, PredicateKind<'tcx>>, ) -> Predicate<'tcx> { if pred.kind() != binder { self.mk_predicate(binder) } else { pred } } #[inline(always)] pub(crate) fn check_and_mk_substs( self, _def_id: DefId, substs: impl IntoIterator>>, ) -> SubstsRef<'tcx> { let substs = substs.into_iter().map(Into::into); #[cfg(debug_assertions)] { let generics = self.generics_of(_def_id); let n = if let DefKind::AssocTy = self.def_kind(_def_id) && let DefKind::Impl { of_trait: false } = self.def_kind(self.parent(_def_id)) { // If this is an inherent projection. generics.params.len() + 1 } else { generics.count() }; assert_eq!( (n, Some(n)), substs.size_hint(), "wrong number of generic parameters for {_def_id:?}: {:?}", substs.collect::>(), ); } self.mk_substs_from_iter(substs) } #[inline] pub fn mk_ct_from_kind(self, kind: ty::ConstKind<'tcx>, ty: Ty<'tcx>) -> Const<'tcx> { self.intern_const(ty::ConstData { kind, ty }) } // Avoid this in favour of more specific `Ty::new_*` methods, where possible. #[allow(rustc::usage_of_ty_tykind)] #[inline] pub fn mk_ty_from_kind(self, st: TyKind<'tcx>) -> Ty<'tcx> { self.interners.intern_ty( st, self.sess, // This is only used to create a stable hashing context. &self.untracked, ) } pub fn mk_param_from_def(self, param: &ty::GenericParamDef) -> GenericArg<'tcx> { match param.kind { GenericParamDefKind::Lifetime => { ty::Region::new_early_bound(self, param.to_early_bound_region_data()).into() } GenericParamDefKind::Type { .. } => Ty::new_param(self, param.index, param.name).into(), GenericParamDefKind::Const { .. } => ty::Const::new_param( self, ParamConst { index: param.index, name: param.name }, self.type_of(param.def_id) .no_bound_vars() .expect("const parameter types cannot be generic"), ) .into(), } } pub fn mk_place_field(self, place: Place<'tcx>, f: FieldIdx, ty: Ty<'tcx>) -> Place<'tcx> { self.mk_place_elem(place, PlaceElem::Field(f, ty)) } pub fn mk_place_deref(self, place: Place<'tcx>) -> Place<'tcx> { self.mk_place_elem(place, PlaceElem::Deref) } pub fn mk_place_downcast( self, place: Place<'tcx>, adt_def: AdtDef<'tcx>, variant_index: VariantIdx, ) -> Place<'tcx> { self.mk_place_elem( place, PlaceElem::Downcast(Some(adt_def.variant(variant_index).name), variant_index), ) } pub fn mk_place_downcast_unnamed( self, place: Place<'tcx>, variant_index: VariantIdx, ) -> Place<'tcx> { self.mk_place_elem(place, PlaceElem::Downcast(None, variant_index)) } pub fn mk_place_index(self, place: Place<'tcx>, index: Local) -> Place<'tcx> { self.mk_place_elem(place, PlaceElem::Index(index)) } /// This method copies `Place`'s projection, add an element and reintern it. Should not be used /// to build a full `Place` it's just a convenient way to grab a projection and modify it in /// flight. pub fn mk_place_elem(self, place: Place<'tcx>, elem: PlaceElem<'tcx>) -> Place<'tcx> { let mut projection = place.projection.to_vec(); projection.push(elem); Place { local: place.local, projection: self.mk_place_elems(&projection) } } pub fn mk_poly_existential_predicates( self, eps: &[PolyExistentialPredicate<'tcx>], ) -> &'tcx List> { assert!(!eps.is_empty()); assert!( eps.array_windows() .all(|[a, b]| a.skip_binder().stable_cmp(self, &b.skip_binder()) != Ordering::Greater) ); self.intern_poly_existential_predicates(eps) } pub fn mk_clauses(self, clauses: &[Clause<'tcx>]) -> &'tcx List> { // FIXME consider asking the input slice to be sorted to avoid // re-interning permutations, in which case that would be asserted // here. self.intern_clauses(clauses) } pub fn mk_const_list_from_iter(self, iter: I) -> T::Output where I: Iterator, T: CollectAndApply, &'tcx List>>, { T::collect_and_apply(iter, |xs| self.mk_const_list(xs)) } // Unlike various other `mk_*_from_iter` functions, this one uses `I: // IntoIterator` instead of `I: Iterator`, and it doesn't have a slice // variant, because of the need to combine `inputs` and `output`. This // explains the lack of `_from_iter` suffix. pub fn mk_fn_sig( self, inputs: I, output: I::Item, c_variadic: bool, unsafety: hir::Unsafety, abi: abi::Abi, ) -> T::Output where I: IntoIterator, T: CollectAndApply, ty::FnSig<'tcx>>, { T::collect_and_apply(inputs.into_iter().chain(iter::once(output)), |xs| ty::FnSig { inputs_and_output: self.mk_type_list(xs), c_variadic, unsafety, abi, }) } pub fn mk_poly_existential_predicates_from_iter(self, iter: I) -> T::Output where I: Iterator, T: CollectAndApply< PolyExistentialPredicate<'tcx>, &'tcx List>, >, { T::collect_and_apply(iter, |xs| self.mk_poly_existential_predicates(xs)) } pub fn mk_clauses_from_iter(self, iter: I) -> T::Output where I: Iterator, T: CollectAndApply, &'tcx List>>, { T::collect_and_apply(iter, |xs| self.mk_clauses(xs)) } pub fn mk_type_list_from_iter(self, iter: I) -> T::Output where I: Iterator, T: CollectAndApply, &'tcx List>>, { T::collect_and_apply(iter, |xs| self.mk_type_list(xs)) } pub fn mk_substs_from_iter(self, iter: I) -> T::Output where I: Iterator, T: CollectAndApply, &'tcx List>>, { T::collect_and_apply(iter, |xs| self.mk_substs(xs)) } pub fn mk_canonical_var_infos_from_iter(self, iter: I) -> T::Output where I: Iterator, T: CollectAndApply, &'tcx List>>, { T::collect_and_apply(iter, |xs| self.mk_canonical_var_infos(xs)) } pub fn mk_place_elems_from_iter(self, iter: I) -> T::Output where I: Iterator, T: CollectAndApply, &'tcx List>>, { T::collect_and_apply(iter, |xs| self.mk_place_elems(xs)) } pub fn mk_fields_from_iter(self, iter: I) -> T::Output where I: Iterator, T: CollectAndApply>, { T::collect_and_apply(iter, |xs| self.mk_fields(xs)) } pub fn mk_substs_trait( self, self_ty: Ty<'tcx>, rest: impl IntoIterator>, ) -> SubstsRef<'tcx> { self.mk_substs_from_iter(iter::once(self_ty.into()).chain(rest)) } pub fn mk_alias_ty( self, def_id: DefId, substs: impl IntoIterator>>, ) -> ty::AliasTy<'tcx> { let substs = self.check_and_mk_substs(def_id, substs); ty::AliasTy { def_id, substs, _use_mk_alias_ty_instead: () } } pub fn mk_bound_variable_kinds_from_iter(self, iter: I) -> T::Output where I: Iterator, T: CollectAndApply>, { T::collect_and_apply(iter, |xs| self.mk_bound_variable_kinds(xs)) } /// Emit a lint at `span` from a lint struct (some type that implements `DecorateLint`, /// typically generated by `#[derive(LintDiagnostic)]`). pub fn emit_spanned_lint( self, lint: &'static Lint, hir_id: HirId, span: impl Into, decorator: impl for<'a> DecorateLint<'a, ()>, ) { let msg = decorator.msg(); let (level, src) = self.lint_level_at_node(lint, hir_id); struct_lint_level(self.sess, lint, level, src, Some(span.into()), msg, |diag| { decorator.decorate_lint(diag) }) } /// Emit a lint at the appropriate level for a hir node, with an associated span. /// /// Return value of the `decorate` closure is ignored, see [`struct_lint_level`] for a detailed explanation. /// /// [`struct_lint_level`]: rustc_middle::lint::struct_lint_level#decorate-signature #[rustc_lint_diagnostics] pub fn struct_span_lint_hir( self, lint: &'static Lint, hir_id: HirId, span: impl Into, msg: impl Into, decorate: impl for<'a, 'b> FnOnce( &'b mut DiagnosticBuilder<'a, ()>, ) -> &'b mut DiagnosticBuilder<'a, ()>, ) { let (level, src) = self.lint_level_at_node(lint, hir_id); struct_lint_level(self.sess, lint, level, src, Some(span.into()), msg, decorate); } /// Emit a lint from a lint struct (some type that implements `DecorateLint`, typically /// generated by `#[derive(LintDiagnostic)]`). pub fn emit_lint( self, lint: &'static Lint, id: HirId, decorator: impl for<'a> DecorateLint<'a, ()>, ) { self.struct_lint_node(lint, id, decorator.msg(), |diag| decorator.decorate_lint(diag)) } /// Emit a lint at the appropriate level for a hir node. /// /// Return value of the `decorate` closure is ignored, see [`struct_lint_level`] for a detailed explanation. /// /// [`struct_lint_level`]: rustc_middle::lint::struct_lint_level#decorate-signature #[rustc_lint_diagnostics] pub fn struct_lint_node( self, lint: &'static Lint, id: HirId, msg: impl Into, decorate: impl for<'a, 'b> FnOnce( &'b mut DiagnosticBuilder<'a, ()>, ) -> &'b mut DiagnosticBuilder<'a, ()>, ) { let (level, src) = self.lint_level_at_node(lint, id); struct_lint_level(self.sess, lint, level, src, None, msg, decorate); } pub fn in_scope_traits(self, id: HirId) -> Option<&'tcx [TraitCandidate]> { let map = self.in_scope_traits_map(id.owner)?; let candidates = map.get(&id.local_id)?; Some(candidates) } pub fn named_bound_var(self, id: HirId) -> Option { debug!(?id, "named_region"); self.named_variable_map(id.owner).and_then(|map| map.get(&id.local_id).cloned()) } pub fn is_late_bound(self, id: HirId) -> bool { self.is_late_bound_map(id.owner).is_some_and(|set| set.contains(&id.local_id)) } pub fn late_bound_vars(self, id: HirId) -> &'tcx List { self.mk_bound_variable_kinds( &self .late_bound_vars_map(id.owner) .and_then(|map| map.get(&id.local_id).cloned()) .unwrap_or_else(|| { bug!("No bound vars found for {}", self.hir().node_to_string(id)) }), ) } /// Whether the `def_id` counts as const fn in the current crate, considering all active /// feature gates pub fn is_const_fn(self, def_id: DefId) -> bool { if self.is_const_fn_raw(def_id) { match self.lookup_const_stability(def_id) { Some(stability) if stability.is_const_unstable() => { // has a `rustc_const_unstable` attribute, check whether the user enabled the // corresponding feature gate. self.features() .declared_lib_features .iter() .any(|&(sym, _)| sym == stability.feature) } // functions without const stability are either stable user written // const fn or the user is using feature gates and we thus don't // care what they do _ => true, } } else { false } } /// Whether the trait impl is marked const. This does not consider stability or feature gates. pub fn is_const_trait_impl_raw(self, def_id: DefId) -> bool { let Some(local_def_id) = def_id.as_local() else { return false }; let hir_id = self.local_def_id_to_hir_id(local_def_id); let node = self.hir().get(hir_id); matches!( node, hir::Node::Item(hir::Item { kind: hir::ItemKind::Impl(hir::Impl { constness: hir::Constness::Const, .. }), .. }) ) } pub fn local_def_id_to_hir_id(self, local_def_id: LocalDefId) -> HirId { self.opt_local_def_id_to_hir_id(local_def_id).unwrap() } pub fn next_trait_solver_globally(self) -> bool { self.sess.opts.unstable_opts.trait_solver == rustc_session::config::TraitSolver::Next } pub fn next_trait_solver_in_coherence(self) -> bool { matches!( self.sess.opts.unstable_opts.trait_solver, rustc_session::config::TraitSolver::Next | rustc_session::config::TraitSolver::NextCoherence ) } pub fn lower_impl_trait_in_trait_to_assoc_ty(self) -> bool { self.sess.opts.unstable_opts.lower_impl_trait_in_trait_to_assoc_ty } pub fn is_impl_trait_in_trait(self, def_id: DefId) -> bool { if self.lower_impl_trait_in_trait_to_assoc_ty() { self.opt_rpitit_info(def_id).is_some() } else { self.def_kind(def_id) == DefKind::ImplTraitPlaceholder } } /// Named module children from all kinds of items, including imports. /// In addition to regular items this list also includes struct and variant constructors, and /// items inside `extern {}` blocks because all of them introduce names into parent module. /// /// Module here is understood in name resolution sense - it can be a `mod` item, /// or a crate root, or an enum, or a trait. /// /// This is not a query, making it a query causes perf regressions /// (probably due to hashing spans in `ModChild`ren). pub fn module_children_local(self, def_id: LocalDefId) -> &'tcx [ModChild] { self.resolutions(()).module_children.get(&def_id).map_or(&[], |v| &v[..]) } } /// Parameter attributes that can only be determined by examining the body of a function instead /// of just its signature. /// /// These can be useful for optimization purposes when a function is directly called. We compute /// them and store them into the crate metadata so that downstream crates can make use of them. /// /// Right now, we only have `read_only`, but `no_capture` and `no_alias` might be useful in the /// future. #[derive(Clone, Copy, PartialEq, Debug, Default, TyDecodable, TyEncodable, HashStable)] pub struct DeducedParamAttrs { /// The parameter is marked immutable in the function and contains no `UnsafeCell` (i.e. its /// type is freeze). pub read_only: bool, } pub fn provide(providers: &mut Providers) { providers.maybe_unused_trait_imports = |tcx, ()| &tcx.resolutions(()).maybe_unused_trait_imports; providers.names_imported_by_glob_use = |tcx, id| { tcx.arena.alloc(UnordSet::from( tcx.resolutions(()).glob_map.get(&id).cloned().unwrap_or_default(), )) }; providers.extern_mod_stmt_cnum = |tcx, id| tcx.resolutions(()).extern_crate_map.get(&id).cloned(); providers.is_panic_runtime = |tcx, LocalCrate| attr::contains_name(tcx.hir().krate_attrs(), sym::panic_runtime); providers.is_compiler_builtins = |tcx, LocalCrate| attr::contains_name(tcx.hir().krate_attrs(), sym::compiler_builtins); providers.has_panic_handler = |tcx, LocalCrate| { // We want to check if the panic handler was defined in this crate tcx.lang_items().panic_impl().is_some_and(|did| did.is_local()) }; providers.source_span = |tcx, def_id| tcx.untracked.source_span.get(def_id).unwrap_or(DUMMY_SP); }