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context.rs
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//! 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, FloatTy, FloatVar,
FloatVid, GenericParamDefKind, ImplPolarity, InferTy, IntTy, IntVar, IntVid, List, ParamConst,
ParamTy, PolyExistentialPredicate, PolyFnSig, Predicate, PredicateKind, Region, RegionKind,
ReprOptions, TraitObjectVisitor, Ty, TyKind, TyVar, TyVid, TypeAndMut, UintTy, 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, DynKind, Interner, TypeFlags};
use std::any::Any;
use std::assert_matches::debug_assert_matches;
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<T> = 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<PolyExistentialPredicate<'tcx>>;
type BinderListTy = Binder<'tcx, &'tcx List<Ty<'tcx>>>;
type ListTy = &'tcx List<Ty<'tcx>>;
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 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<InternedInSet<'tcx, T>, ()>;
pub struct CtxtInterners<'tcx> {
/// The arena that types, regions, etc. are allocated from.
arena: &'tcx WorkerLocal<Arena<'tcx>>,
// Specifically use a speedy hash algorithm for these hash sets, since
// they're accessed quite often.
type_: InternedSet<'tcx, WithCachedTypeInfo<TyKind<'tcx>>>,
const_lists: InternedSet<'tcx, List<ty::Const<'tcx>>>,
substs: InternedSet<'tcx, InternalSubsts<'tcx>>,
type_lists: InternedSet<'tcx, List<Ty<'tcx>>>,
canonical_var_infos: InternedSet<'tcx, List<CanonicalVarInfo<'tcx>>>,
region: InternedSet<'tcx, RegionKind<'tcx>>,
poly_existential_predicates: InternedSet<'tcx, List<PolyExistentialPredicate<'tcx>>>,
predicate: InternedSet<'tcx, WithCachedTypeInfo<ty::Binder<'tcx, PredicateKind<'tcx>>>>,
clauses: InternedSet<'tcx, List<Clause<'tcx>>>,
projs: InternedSet<'tcx, List<ProjectionKind>>,
place_elems: InternedSet<'tcx, List<PlaceElem<'tcx>>>,
const_: InternedSet<'tcx, ConstData<'tcx>>,
const_allocation: InternedSet<'tcx, Allocation>,
bound_variable_kinds: InternedSet<'tcx, List<ty::BoundVariableKind>>,
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<FieldIdx>>,
}
impl<'tcx> CtxtInterners<'tcx> {
fn new(arena: &'tcx WorkerLocal<Arena<'tcx>>) -> 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<StableHashingContext<'a>>>(
&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<Ty<'tcx>>,
/// Pre-interned `Infer(ty::FreshTy(n))` for small values of `n`.
pub fresh_tys: Vec<Ty<'tcx>>,
/// Pre-interned `Infer(ty::FreshIntTy(n))` for small values of `n`.
pub fresh_int_tys: Vec<Ty<'tcx>>,
/// Pre-interned `Infer(ty::FreshFloatTy(n))` for small values of `n`.
pub fresh_float_tys: Vec<Ty<'tcx>>,
}
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<Region<'tcx>>,
/// 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<Vec<Region<'tcx>>>,
}
pub struct CommonConsts<'tcx> {
pub unit: 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,
}),
}
}
}
/// 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<Ty<'tcx>>) {
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<Arena<'tcx>>,
pub hir_arena: &'tcx WorkerLocal<hir::Arena<'tcx>>,
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<dyn Any + sync::DynSync + sync::DynSend>,
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<FxHashMap<ty::CReaderCacheKey, Ty<'tcx>>>,
pub pred_rcache: Lock<FxHashMap<ty::CReaderCacheKey, Predicate<'tcx>>>,
/// 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<interpret::AllocMap<'tcx>>,
}
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<Thir<'tcx>> {
self.arena.alloc(Steal::new(thir))
}
pub fn alloc_steal_mir(self, mir: Body<'tcx>) -> &'tcx Steal<Body<'tcx>> {
self.arena.alloc(Steal::new(mir))
}
pub fn alloc_steal_promoted(
self,
promoted: IndexVec<Promoted, Body<'tcx>>,
) -> &'tcx Steal<IndexVec<Promoted, Body<'tcx>>> {
self.arena.alloc(Steal::new(promoted))
}
pub fn mk_adt_def(
self,
did: DefId,
kind: AdtKind,
variants: IndexVec<VariantIdx, ty::VariantDef>,
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<u128>, Bound<u128>) {
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<T: Lift<'tcx>>(self, value: T) -> Option<T::Lifted> {
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<dyn Any + sync::DynSend + sync::DynSync>,
arena: &'tcx WorkerLocal<Arena<'tcx>>,
hir_arena: &'tcx WorkerLocal<hir::Arena<'tcx>>,
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()),
}
}
/// Constructs a `TyKind::Error` type with current `ErrorGuaranteed`
#[track_caller]
pub fn ty_error(self, reported: ErrorGuaranteed) -> Ty<'tcx> {
self.mk_ty_from_kind(Error(reported))
}
/// Constructs a `TyKind::Error` type and registers a `delay_span_bug` to ensure it gets used.
#[track_caller]
pub fn ty_error_misc(self) -> Ty<'tcx> {
self.ty_error_with_message(DUMMY_SP, "TyKind::Error constructed but no error reported")
}
/// Constructs a `TyKind::Error` type and registers a `delay_span_bug` with the given `msg` to
/// ensure it gets used.
#[track_caller]
pub fn ty_error_with_message<S: Into<MultiSpan>>(
self,
span: S,
msg: impl Into<DiagnosticMessage>,
) -> Ty<'tcx> {
let reported = self.sess.delay_span_bug(span, msg);
self.mk_ty_from_kind(Error(reported))
}
/// Like [TyCtxt::ty_error] but for constants, with current `ErrorGuaranteed`
#[track_caller]
pub fn const_error(self, ty: Ty<'tcx>, reported: ErrorGuaranteed) -> Const<'tcx> {
self.mk_const(ty::ConstKind::Error(reported), ty)
}
/// Like [TyCtxt::ty_error] but for constants.
#[track_caller]
pub fn const_error_misc(self, ty: Ty<'tcx>) -> Const<'tcx> {
self.const_error_with_message(
ty,
DUMMY_SP,
"ty::ConstKind::Error constructed but no error reported",
)
}
/// Like [TyCtxt::ty_error_with_message] but for constants.
#[track_caller]
pub fn const_error_with_message<S: Into<MultiSpan>>(
self,
ty: Ty<'tcx>,
span: S,
msg: &'static str,
) -> Const<'tcx> {
let reported = self.sess.delay_span_bug(span, msg);
self.mk_const(ty::ConstKind::Error(reported), ty)
}
pub fn consider_optimizing<T: Fn() -> 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<DefId> {
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<Symbol> {
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<DefId>) -> 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<Item = LocalDefId> + '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