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rust/rust/573bd7d4ada3677648942e644f0894de7d22ac14/./compiler/rustc_middle/src/ty/mod.rs
blob: 98b44f072075a13a678bb1257b555b4f2e48c2ab [file]
//! Defines how the compiler represents types internally.
//!
//! Two important entities in this module are:
//!
//! - [`rustc_middle::ty::Ty`], used to represent the semantics of a type.
//! - [`rustc_middle::ty::TyCtxt`], the central data structure in the compiler.
//!
//! For more information, see ["The `ty` module: representing types"] in the rustc-dev-guide.
//!
//! ["The `ty` module: representing types"]: https://rustc-dev-guide.rust-lang.org/ty.html
#![allow(rustc::usage_of_ty_tykind)]
use std::cmp::Ordering;
use std::fmt::Debug;
use std::hash::{Hash, Hasher};
use std::marker::PhantomData;
use std::num::NonZero;
use std::ptr::NonNull;
use std::{assert_matches, fmt, iter, str};
pub use adt::*;
pub use assoc::*;
pub use generic_args::{GenericArgKind, TermKind, *};
pub use generics::*;
pub use intrinsic::IntrinsicDef;
use rustc_abi::{
Align, FieldIdx, Integer, IntegerType, ReprFlags, ReprOptions, ScalableElt, VariantIdx,
};
use rustc_ast::node_id::NodeMap;
use rustc_ast::{self as ast};
pub use rustc_ast_ir::{Movability, Mutability, try_visit};
use rustc_data_structures::fx::{FxIndexMap, FxIndexSet};
use rustc_data_structures::intern::Interned;
use rustc_data_structures::stable_hash::{StableHash, StableHashCtxt, StableHasher};
use rustc_data_structures::steal::Steal;
use rustc_data_structures::unord::{UnordMap, UnordSet};
use rustc_errors::{Diag, ErrorGuaranteed, LintBuffer};
use rustc_hir::attrs::StrippedCfgItem;
use rustc_hir::def::{CtorKind, CtorOf, DefKind, DocLinkResMap, LifetimeRes, Res};
use rustc_hir::def_id::{CrateNum, DefId, DefIdMap, LocalDefId, LocalDefIdMap};
use rustc_hir::definitions::PerParentDisambiguatorState;
use rustc_hir::{self as hir, LangItem, MissingLifetimeKind, attrs as attr, find_attr};
use rustc_index::IndexVec;
use rustc_index::bit_set::BitMatrix;
use rustc_macros::{
BlobDecodable, Decodable, Encodable, StableHash, TyDecodable, TyEncodable, TypeFoldable,
TypeVisitable, extension,
};
use rustc_serialize::{Decodable, Encodable};
use rustc_session::config::OptLevel;
pub use rustc_session::lint::RegisteredTools;
use rustc_span::hygiene::MacroKind;
use rustc_span::{DUMMY_SP, ExpnId, ExpnKind, Ident, Span, Symbol};
use rustc_target::callconv::FnAbi;
pub use rustc_type_ir::data_structures::{DelayedMap, DelayedSet};
pub use rustc_type_ir::fast_reject::DeepRejectCtxt;
#[allow(
hidden_glob_reexports,
rustc::usage_of_type_ir_inherent,
rustc::non_glob_import_of_type_ir_inherent
)]
use rustc_type_ir::inherent;
pub use rustc_type_ir::relate::VarianceDiagInfo;
pub use rustc_type_ir::solve::{CandidatePreferenceMode, SizedTraitKind, VisibleForLeakCheck};
pub use rustc_type_ir::*;
#[allow(hidden_glob_reexports, unused_imports)]
use rustc_type_ir::{InferCtxtLike, Interner};
use tracing::{debug, instrument};
pub use vtable::*;
pub use self::closure::{
BorrowKind, CAPTURE_STRUCT_LOCAL, CaptureInfo, CapturedPlace, ClosureTypeInfo,
MinCaptureInformationMap, MinCaptureList, RootVariableMinCaptureList, UpvarCapture, UpvarId,
UpvarPath, analyze_coroutine_closure_captures, is_ancestor_or_same_capture,
place_to_string_for_capture,
};
pub use self::consts::{
AliasConst, AliasConstKind, AtomicOrdering, Const, ConstInt, ConstKind, ConstToValTreeResult,
Expr, ExprKind, LitToConstInput, ScalarInt, SimdAlign, ValTree, ValTreeKindExt, Value,
const_lit_matches_ty,
};
pub use self::context::{
CtxtInterners, CurrentGcx, FreeRegionInfo, GlobalCtxt, Lift, TyCtxt, TyCtxtFeed, tls,
};
pub use self::fold::*;
pub use self::instance::{Instance, InstanceKind, ReifyReason, ShimKind};
pub(crate) use self::list::RawList;
pub use self::list::{List, ListWithCachedTypeInfo};
pub use self::opaque_types::OpaqueTypeKey;
pub use self::pattern::{Pattern, PatternKind};
pub use self::predicate::{
AliasTerm, AliasTermKind, ArgOutlivesPredicate, Clause, ClauseKind, CoercePredicate,
ExistentialPredicate, ExistentialPredicateStableCmpExt, ExistentialProjection,
ExistentialTraitRef, HostEffectPredicate, NormalizesTo, OutlivesPredicate, PolyCoercePredicate,
PolyExistentialPredicate, PolyExistentialProjection, PolyExistentialTraitRef,
PolyProjectionPredicate, PolyRegionOutlivesPredicate, PolySubtypePredicate, PolyTraitPredicate,
PolyTraitRef, PolyTypeOutlivesPredicate, Predicate, PredicateKind, ProjectionPredicate,
RegionConstraint, RegionEqPredicate, RegionOutlivesPredicate, SubtypePredicate, TraitPredicate,
TraitRef, TypeOutlivesPredicate,
};
pub use self::region::{
EarlyParamRegion, LateParamRegion, LateParamRegionKind, Region, RegionKind, RegionVid,
};
pub use self::sty::{
Alias, AliasTy, AliasTyKind, Article, Binder, BoundConst, BoundRegion, BoundRegionKind,
BoundTy, BoundTyKind, BoundVariableKind, CanonicalPolyFnSig, CoroutineArgsExt, EarlyBinder,
FnSig, FnSigKind, FreeAliasTy, InherentAliasTy, InlineConstArgs, InlineConstArgsParts,
OpaqueAliasTy, ParamConst, ParamTy, PlaceholderConst, PlaceholderRegion, PlaceholderType,
PolyFnSig, ProjectionAliasTy, TyKind, TypeAndMut, TypingMode, TypingModeEqWrapper,
Unnormalized, UpvarArgs,
};
pub use self::trait_def::TraitDef;
pub use self::typeck_results::{
CanonicalUserType, CanonicalUserTypeAnnotation, CanonicalUserTypeAnnotations, IsIdentity,
Rust2024IncompatiblePatInfo, SplattedDef, TypeckResults, UserType, UserTypeAnnotationIndex,
UserTypeKind,
};
use crate::error::{OpaqueHiddenTypeMismatch, TypeMismatchReason};
use crate::metadata::{AmbigModChild, ModChild};
use crate::middle::privacy::EffectiveVisibilities;
use crate::mir::{Body, CoroutineLayout, CoroutineSavedLocal, MirPhase, SourceInfo};
use crate::query::{IntoQueryKey, Providers};
use crate::ty;
use crate::ty::codec::{TyDecoder, TyEncoder};
pub use crate::ty::diagnostics::*;
use crate::ty::fast_reject::SimplifiedType;
use crate::ty::layout::{FnAbiError, LayoutError};
use crate::ty::util::Discr;
use crate::ty::walk::TypeWalker;
pub mod abstract_const;
pub mod adjustment;
pub mod cast;
pub mod codec;
pub mod error;
pub mod fast_reject;
pub mod inhabitedness;
pub mod layout;
pub mod normalize_erasing_regions;
pub mod offload_meta;
pub mod pattern;
pub mod print;
pub mod relate;
pub mod significant_drop_order;
pub mod trait_def;
pub mod typetree;
pub mod util;
pub mod vtable;
mod adt;
mod assoc;
mod closure;
mod consts;
mod context;
mod diagnostics;
mod elaborate_impl;
mod erase_regions;
mod fold;
mod generic_args;
mod generics;
mod impls_ty;
mod instance;
mod intrinsic;
mod list;
mod opaque_types;
mod predicate;
mod region;
mod structural_impls;
#[allow(hidden_glob_reexports)]
mod sty;
mod typeck_results;
mod visit;
// Data types
#[derive(Debug, StableHash)]
pub struct ResolverGlobalCtxt {
pub visibilities_for_hashing: Vec<(LocalDefId, Visibility)>,
/// Item with a given `LocalDefId` was defined during macro expansion with ID `ExpnId`.
pub expn_that_defined: UnordMap<LocalDefId, ExpnId>,
pub effective_visibilities: EffectiveVisibilities,
// FIXME: This table contains ADTs reachable from macro 2.0.
// Currently, reachability of a definition from a macro is determined by nominal visibility
// (see `compute_effective_visibilities`). This is incorrect and leads to the necessity
// of traversing ADT fields in `rustc_privacy`. Remove this workaround once the
// correct reachability logic is implemented for macros.
pub macro_reachable_adts: FxIndexMap<LocalDefId, FxIndexSet<LocalDefId>>,
pub extern_crate_map: UnordMap<LocalDefId, CrateNum>,
pub maybe_unused_trait_imports: FxIndexSet<LocalDefId>,
pub module_children: LocalDefIdMap<Vec<ModChild>>,
pub ambig_module_children: LocalDefIdMap<Vec<AmbigModChild>>,
pub glob_map: FxIndexMap<LocalDefId, FxIndexSet<Symbol>>,
pub main_def: Option<MainDefinition>,
pub trait_impls: FxIndexMap<DefId, Vec<LocalDefId>>,
/// A list of proc macro LocalDefIds, written out in the order in which
/// they are declared in the static array generated by proc_macro_harness.
pub proc_macros: Vec<LocalDefId>,
/// Mapping from ident span to path span for paths that don't exist as written, but that
/// exist under `std`. For example, wrote `str::from_utf8` instead of `std::str::from_utf8`.
pub confused_type_with_std_module: FxIndexMap<Span, Span>,
pub doc_link_resolutions: FxIndexMap<LocalDefId, DocLinkResMap>,
pub doc_link_traits_in_scope: FxIndexMap<LocalDefId, Vec<DefId>>,
pub all_macro_rules: UnordSet<Symbol>,
pub stripped_cfg_items: Vec<StrippedCfgItem>,
// Information about delegations which is used when handling recursive delegations
// and ensures easy access to delegation-only `LocalDefId`s.
pub delegation_infos: FxIndexMap<LocalDefId, DelegationInfo>,
}
#[derive(Debug)]
pub struct PerOwnerResolverData<'tcx> {
pub node_id_to_def_id: NodeMap<LocalDefId> = Default::default(),
/// Whether lifetime elision was successful.
pub lifetime_elision_allowed: bool = false,
/// Resolutions for labels.
/// Maps from NodeId of the break/continue expression to the NodeId of their corresponding blocks or loops.
pub label_res_map: NodeMap<ast::NodeId> = Default::default(),
/// Resolutions for lifetimes.
pub lifetimes_res_map: NodeMap<LifetimeRes> = Default::default(),
pub trait_map: NodeMap<&'tcx [hir::TraitCandidate<'tcx>]> = Default::default(),
/// Resolution for import nodes, which have multiple resolutions in different namespaces.
pub import_res: hir::def::PerNS<Option<Res<ast::NodeId>>> = Default::default(),
/// The id of the owner
pub id: ast::NodeId,
/// The `DefId` of the owner, can't be found in `node_id_to_def_id`.
pub def_id: LocalDefId,
}
impl<'tcx> PerOwnerResolverData<'tcx> {
pub fn new(id: ast::NodeId, def_id: LocalDefId) -> PerOwnerResolverData<'tcx> {
PerOwnerResolverData { id, def_id, .. }
}
/// Obtains resolution for a label with the given `NodeId`.
pub fn get_label_res(&self, id: ast::NodeId) -> Option<ast::NodeId> {
self.label_res_map.get(&id).copied()
}
/// Obtains resolution for a lifetime with the given `NodeId`.
pub fn get_lifetime_res(&self, id: ast::NodeId) -> Option<LifetimeRes> {
self.lifetimes_res_map.get(&id).copied()
}
}
/// Resolutions that should only be used for lowering.
/// This struct is meant to be consumed by lowering.
#[derive(Debug)]
pub struct ResolverAstLowering<'tcx> {
/// Resolutions for nodes that have a single resolution.
pub partial_res_map: NodeMap<hir::def::PartialRes>,
/// Lifetime parameters that lowering will have to introduce.
pub extra_lifetime_params_map: NodeMap<Vec<(Ident, ast::NodeId, MissingLifetimeKind)>>,
pub next_node_id: ast::NodeId,
pub owners: NodeMap<PerOwnerResolverData<'tcx>>,
/// Lints that were emitted by the resolver and early lints.
pub lint_buffer: Steal<LintBuffer>,
pub disambiguators: LocalDefIdMap<Steal<PerParentDisambiguatorState>>,
}
#[derive(Debug, StableHash)]
pub struct DelegationInfo {
// `DefId` (either the resolution at delegation.id or item_id in case of a trait impl) for signature resolution,
// for details see https://github.com/rust-lang/rust/issues/118212#issuecomment-2160686914
/// Refers to the next element in a delegation resolution chain.
/// Usually points to the final resolution, as most "chains" are just
/// one step to a trait or an impl.
pub resolution_id: Result<DefId, ErrorGuaranteed>,
}
#[derive(Clone, Copy, Debug, StableHash)]
pub struct MainDefinition {
pub res: Res<ast::NodeId>,
pub is_import: bool,
pub span: Span,
}
impl MainDefinition {
pub fn opt_fn_def_id(self) -> Option<DefId> {
if let Res::Def(DefKind::Fn, def_id) = self.res { Some(def_id) } else { None }
}
}
#[derive(Copy, Clone, Debug, TyEncodable, TyDecodable, StableHash)]
pub struct ImplTraitHeader<'tcx> {
pub trait_ref: ty::EarlyBinder<'tcx, ty::TraitRef<'tcx>>,
pub polarity: ImplPolarity,
pub safety: hir::Safety,
pub constness: hir::Constness,
}
#[derive(Copy, Clone, PartialEq, Eq, Hash, TyEncodable, TyDecodable, StableHash, Debug)]
#[derive(TypeFoldable, TypeVisitable, Default)]
pub enum Asyncness {
Yes,
#[default]
No,
}
impl Asyncness {
pub fn is_async(self) -> bool {
matches!(self, Asyncness::Yes)
}
}
#[derive(Clone, Debug, PartialEq, Eq, Copy, Hash, Encodable, BlobDecodable, StableHash)]
pub enum Visibility<Id = LocalDefId> {
/// Visible everywhere (including in other crates).
Public,
/// Visible only in the given crate-local module.
Restricted(Id),
}
impl Visibility {
pub fn to_string(self, def_id: LocalDefId, tcx: TyCtxt<'_>) -> String {
match self {
ty::Visibility::Restricted(restricted_id) => {
if restricted_id.is_top_level_module() {
"pub(crate)".to_string()
} else if restricted_id == tcx.parent_module_from_def_id(def_id).to_local_def_id() {
"pub(self)".to_string()
} else {
format!(
"pub(in crate{})",
tcx.def_path(restricted_id.to_def_id()).to_string_no_crate_verbose()
)
}
}
ty::Visibility::Public => "pub".to_string(),
}
}
}
#[derive(Clone, Debug, PartialEq, Eq, Copy, Hash, TyEncodable, TyDecodable, StableHash)]
#[derive(TypeFoldable, TypeVisitable)]
pub struct ClosureSizeProfileData<'tcx> {
/// Tuple containing the types of closure captures before the feature `capture_disjoint_fields`
pub before_feature_tys: Ty<'tcx>,
/// Tuple containing the types of closure captures after the feature `capture_disjoint_fields`
pub after_feature_tys: Ty<'tcx>,
}
impl TyCtxt<'_> {
#[inline]
pub fn opt_parent(self, id: DefId) -> Option<DefId> {
self.def_key(id).parent.map(|index| DefId { index, ..id })
}
#[inline]
#[track_caller]
pub fn parent(self, id: DefId) -> DefId {
match self.opt_parent(id) {
Some(id) => id,
// not `unwrap_or_else` to avoid breaking caller tracking
None => bug!("{id:?} doesn't have a parent"),
}
}
#[inline]
#[track_caller]
pub fn opt_local_parent(self, id: LocalDefId) -> Option<LocalDefId> {
self.opt_parent(id.to_def_id()).map(DefId::expect_local)
}
#[inline]
#[track_caller]
pub fn local_parent(self, id: impl Into<LocalDefId>) -> LocalDefId {
self.parent(id.into().to_def_id()).expect_local()
}
/// Compare def-ids based on their position in def-id tree, ancestor def-ids are considered
/// larger than descendant def-ids, and two different def-ids are considered unordered if
/// neither of them is an ancestor of the other.
fn def_id_partial_cmp(self, lhs: DefId, rhs: DefId) -> Option<Ordering> {
// Def-ids from different crates are always unordered.
if lhs.krate != rhs.krate {
return None;
}
// Def-ids of parent nodes are always created before def-ids of child nodes
// and have a smaller index, so we only need to search in one direction,
// either from lhs to rhs, or vice versa.
let search = |mut start: DefId, finish: DefId, ord| {
while start.index != finish.index {
match self.opt_parent(start) {
Some(parent) => start.index = parent.index,
None => return None,
}
}
Some(ord)
};
match lhs.index.cmp(&rhs.index) {
Ordering::Equal => Some(Ordering::Equal),
Ordering::Less => search(rhs, lhs, Ordering::Greater),
Ordering::Greater => search(lhs, rhs, Ordering::Less),
}
}
pub fn is_descendant_of(self, descendant: DefId, ancestor: DefId) -> bool {
matches!(
self.def_id_partial_cmp(descendant, ancestor),
Some(Ordering::Less | Ordering::Equal)
)
}
}
impl<Id> Visibility<Id> {
pub fn is_public(self) -> bool {
matches!(self, Visibility::Public)
}
pub fn map_id<OutId>(self, f: impl FnOnce(Id) -> OutId) -> Visibility<OutId> {
match self {
Visibility::Public => Visibility::Public,
Visibility::Restricted(id) => Visibility::Restricted(f(id)),
}
}
}
impl<Id: Into<DefId>> Visibility<Id> {
pub fn to_def_id(self) -> Visibility<DefId> {
self.map_id(Into::into)
}
/// Returns `true` if an item with this visibility is accessible from the given module.
pub fn is_accessible_from(self, module: impl Into<DefId>, tcx: TyCtxt<'_>) -> bool {
match self {
// Public items are visible everywhere.
Visibility::Public => true,
Visibility::Restricted(id) => tcx.is_descendant_of(module.into(), id.into()),
}
}
pub fn partial_cmp(
self,
vis: Visibility<impl Into<DefId>>,
tcx: TyCtxt<'_>,
) -> Option<Ordering> {
match (self, vis) {
(Visibility::Public, Visibility::Public) => Some(Ordering::Equal),
(Visibility::Public, Visibility::Restricted(_)) => Some(Ordering::Greater),
(Visibility::Restricted(_), Visibility::Public) => Some(Ordering::Less),
(Visibility::Restricted(lhs_id), Visibility::Restricted(rhs_id)) => {
let (lhs_id, rhs_id) = (lhs_id.into(), rhs_id.into());
tcx.def_id_partial_cmp(lhs_id, rhs_id)
}
}
}
}
impl<Id: Into<DefId> + Debug + Copy> Visibility<Id> {
/// Returns `true` if this visibility is strictly larger than the given visibility.
#[track_caller]
pub fn greater_than(
self,
vis: Visibility<impl Into<DefId> + Debug + Copy>,
tcx: TyCtxt<'_>,
) -> bool {
match self.partial_cmp(vis, tcx) {
Some(ord) => ord.is_gt(),
None => {
tcx.dcx().delayed_bug(format!("unordered visibilities: {self:?} and {vis:?}"));
false
}
}
}
}
impl Visibility<DefId> {
pub fn expect_local(self) -> Visibility {
self.map_id(|id| id.expect_local())
}
/// Returns `true` if this item is visible anywhere in the local crate.
pub fn is_visible_locally(self) -> bool {
match self {
Visibility::Public => true,
Visibility::Restricted(def_id) => def_id.is_local(),
}
}
}
/// The crate variances map is computed during typeck and contains the
/// variance of every item in the local crate. You should not use it
/// directly, because to do so will make your pass dependent on the
/// HIR of every item in the local crate. Instead, use
/// `tcx.variances_of()` to get the variance for a *particular*
/// item.
#[derive(StableHash, Debug)]
pub struct CrateVariancesMap<'tcx> {
/// For each item with generics, maps to a vector of the variance
/// of its generics. If an item has no generics, it will have no
/// entry.
pub variances: DefIdMap<&'tcx [ty::Variance]>,
}
// Contains information needed to resolve types and (in the future) look up
// the types of AST nodes.
#[derive(Copy, Clone, PartialEq, Eq, Hash)]
pub struct CReaderCacheKey {
pub cnum: Option<CrateNum>,
pub pos: usize,
}
/// Use this rather than `TyKind`, whenever possible.
#[derive(Copy, Clone, PartialEq, Eq, Hash, StableHash)]
#[rustc_diagnostic_item = "Ty"]
#[rustc_pass_by_value]
pub struct Ty<'tcx>(Interned<'tcx, WithCachedTypeInfo<TyKind<'tcx>>>);
impl<'tcx> rustc_type_ir::inherent::IntoKind for Ty<'tcx> {
type Kind = TyKind<'tcx>;
fn kind(self) -> TyKind<'tcx> {
*self.kind()
}
}
impl<'tcx> rustc_type_ir::Flags for Ty<'tcx> {
fn flags(&self) -> TypeFlags {
self.0.flags
}
fn outer_exclusive_binder(&self) -> DebruijnIndex {
self.0.outer_exclusive_binder
}
}
/// The crate outlives map is computed during typeck and contains the
/// outlives of every item in the local crate. You should not use it
/// directly, because to do so will make your pass dependent on the
/// HIR of every item in the local crate. Instead, use
/// `tcx.inferred_outlives_of()` to get the outlives for a *particular*
/// item.
#[derive(StableHash, Debug)]
pub struct CratePredicatesMap<'tcx> {
/// For each struct with outlive bounds, maps to a vector of the
/// predicate of its outlive bounds. If an item has no outlives
/// bounds, it will have no entry.
pub predicates: DefIdMap<&'tcx [(Clause<'tcx>, Span)]>,
}
#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub struct Term<'tcx> {
ptr: NonNull<()>,
marker: PhantomData<(Ty<'tcx>, Const<'tcx>)>,
}
impl<'tcx> rustc_type_ir::inherent::Term<TyCtxt<'tcx>> for Term<'tcx> {}
impl<'tcx> rustc_type_ir::inherent::IntoKind for Term<'tcx> {
type Kind = TermKind<'tcx>;
fn kind(self) -> Self::Kind {
self.kind()
}
}
unsafe impl<'tcx> rustc_data_structures::sync::DynSend for Term<'tcx> where
&'tcx (Ty<'tcx>, Const<'tcx>): rustc_data_structures::sync::DynSend
{
}
unsafe impl<'tcx> rustc_data_structures::sync::DynSync for Term<'tcx> where
&'tcx (Ty<'tcx>, Const<'tcx>): rustc_data_structures::sync::DynSync
{
}
unsafe impl<'tcx> Send for Term<'tcx> where &'tcx (Ty<'tcx>, Const<'tcx>): Send {}
unsafe impl<'tcx> Sync for Term<'tcx> where &'tcx (Ty<'tcx>, Const<'tcx>): Sync {}
impl Debug for Term<'_> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self.kind() {
TermKind::Ty(ty) => write!(f, "Term::Ty({ty:?})"),
TermKind::Const(ct) => write!(f, "Term::Const({ct:?})"),
}
}
}
impl<'tcx> From<Ty<'tcx>> for Term<'tcx> {
fn from(ty: Ty<'tcx>) -> Self {
TermKind::Ty(ty).pack()
}
}
impl<'tcx> From<Const<'tcx>> for Term<'tcx> {
fn from(c: Const<'tcx>) -> Self {
TermKind::Const(c).pack()
}
}
impl<'tcx> StableHash for Term<'tcx> {
fn stable_hash<Hcx: StableHashCtxt>(&self, hcx: &mut Hcx, hasher: &mut StableHasher) {
self.kind().stable_hash(hcx, hasher);
}
}
impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for Term<'tcx> {
fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
self,
folder: &mut F,
) -> Result<Self, F::Error> {
match self.kind() {
ty::TermKind::Ty(ty) => ty.try_fold_with(folder).map(Into::into),
ty::TermKind::Const(ct) => ct.try_fold_with(folder).map(Into::into),
}
}
fn fold_with<F: TypeFolder<TyCtxt<'tcx>>>(self, folder: &mut F) -> Self {
match self.kind() {
ty::TermKind::Ty(ty) => ty.fold_with(folder).into(),
ty::TermKind::Const(ct) => ct.fold_with(folder).into(),
}
}
}
impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for Term<'tcx> {
fn visit_with<V: TypeVisitor<TyCtxt<'tcx>>>(&self, visitor: &mut V) -> V::Result {
match self.kind() {
ty::TermKind::Ty(ty) => ty.visit_with(visitor),
ty::TermKind::Const(ct) => ct.visit_with(visitor),
}
}
}
impl<'tcx, E: TyEncoder<'tcx>> Encodable<E> for Term<'tcx> {
fn encode(&self, e: &mut E) {
self.kind().encode(e)
}
}
impl<'tcx, D: TyDecoder<'tcx>> Decodable<D> for Term<'tcx> {
fn decode(d: &mut D) -> Self {
let res: TermKind<'tcx> = Decodable::decode(d);
res.pack()
}
}
impl<'tcx> Term<'tcx> {
#[inline]
pub fn kind(self) -> TermKind<'tcx> {
let ptr =
unsafe { self.ptr.map_addr(|addr| NonZero::new_unchecked(addr.get() & !TAG_MASK)) };
// SAFETY: use of `Interned::new_unchecked` here is ok because these
// pointers were originally created from `Interned` types in `pack()`,
// and this is just going in the other direction.
unsafe {
match self.ptr.addr().get() & TAG_MASK {
TYPE_TAG => TermKind::Ty(Ty(Interned::new_unchecked(
ptr.cast::<WithCachedTypeInfo<ty::TyKind<'tcx>>>().as_ref(),
))),
CONST_TAG => TermKind::Const(ty::Const(Interned::new_unchecked(
ptr.cast::<WithCachedTypeInfo<ty::ConstKind<'tcx>>>().as_ref(),
))),
_ => core::intrinsics::unreachable(),
}
}
}
pub fn as_type(&self) -> Option<Ty<'tcx>> {
if let TermKind::Ty(ty) = self.kind() { Some(ty) } else { None }
}
pub fn expect_type(&self) -> Ty<'tcx> {
self.as_type().expect("expected a type, but found a const")
}
pub fn as_const(&self) -> Option<Const<'tcx>> {
if let TermKind::Const(c) = self.kind() { Some(c) } else { None }
}
pub fn expect_const(&self) -> Const<'tcx> {
self.as_const().expect("expected a const, but found a type")
}
pub fn into_arg(self) -> GenericArg<'tcx> {
match self.kind() {
TermKind::Ty(ty) => ty.into(),
TermKind::Const(c) => c.into(),
}
}
pub fn to_alias_term(self) -> Option<AliasTerm<'tcx>> {
match self.kind() {
TermKind::Ty(ty) => match *ty.kind() {
ty::Alias(_, alias_ty) => Some(alias_ty.into()),
_ => None,
},
TermKind::Const(ct) => match ct.kind() {
ConstKind::Alias(_, alias_const) => Some(alias_const.into()),
_ => None,
},
}
}
pub fn is_non_rigid_alias(self) -> bool {
match self.kind() {
ty::TermKind::Ty(ty) => match ty.kind() {
ty::Alias(ty::IsRigid::No, _) => true,
_ => false,
},
ty::TermKind::Const(ct) => match ct.kind() {
ty::ConstKind::Alias(ty::IsRigid::No, _) => true,
_ => false,
},
}
}
pub fn is_infer(&self) -> bool {
match self.kind() {
TermKind::Ty(ty) => ty.is_ty_var(),
TermKind::Const(ct) => ct.is_ct_infer(),
}
}
pub fn is_trivially_wf(&self, tcx: TyCtxt<'tcx>) -> bool {
match self.kind() {
TermKind::Ty(ty) => ty.is_trivially_wf(tcx),
TermKind::Const(ct) => ct.is_trivially_wf(),
}
}
/// Iterator that walks `self` and any types reachable from
/// `self`, in depth-first order. Note that just walks the types
/// that appear in `self`, it does not descend into the fields of
/// structs or variants. For example:
///
/// ```text
/// isize => { isize }
/// Foo<Bar<isize>> => { Foo<Bar<isize>>, Bar<isize>, isize }
/// [isize] => { [isize], isize }
/// ```
pub fn walk(self) -> TypeWalker<TyCtxt<'tcx>> {
TypeWalker::new(self.into())
}
}
const TAG_MASK: usize = 0b11;
const TYPE_TAG: usize = 0b00;
const CONST_TAG: usize = 0b01;
#[extension(pub trait TermKindPackExt<'tcx>)]
impl<'tcx> TermKind<'tcx> {
#[inline]
fn pack(self) -> Term<'tcx> {
let (tag, ptr) = match self {
TermKind::Ty(ty) => {
// Ensure we can use the tag bits.
assert_eq!(align_of_val(&*ty.0.0) & TAG_MASK, 0);
(TYPE_TAG, NonNull::from(ty.0.0).cast())
}
TermKind::Const(ct) => {
// Ensure we can use the tag bits.
assert_eq!(align_of_val(&*ct.0.0) & TAG_MASK, 0);
(CONST_TAG, NonNull::from(ct.0.0).cast())
}
};
Term { ptr: ptr.map_addr(|addr| addr | tag), marker: PhantomData }
}
}
/// Represents the bounds declared on a particular set of type
/// parameters. Should eventually be generalized into a flag list of
/// where-clauses. You can obtain an `InstantiatedPredicates` list from a
/// `GenericPredicates` by using the `instantiate` method. Note that this method
/// reflects an important semantic invariant of `InstantiatedPredicates`: while
/// the `GenericPredicates` are expressed in terms of the bound type
/// parameters of the impl/trait/whatever, an `InstantiatedPredicates` instance
/// represented a set of bounds for some particular instantiation,
/// meaning that the generic parameters have been instantiated with
/// their values.
///
/// Example:
/// ```ignore (illustrative)
/// struct Foo<T, U: Bar<T>> { ... }
/// ```
/// Here, the `GenericPredicates` for `Foo` would contain a list of bounds like
/// `[[], [U:Bar<T>]]`. Now if there were some particular reference
/// like `Foo<isize,usize>`, then the `InstantiatedPredicates` would be `[[],
/// [usize:Bar<isize>]]`.
#[derive(Clone, Debug)]
pub struct InstantiatedPredicates<'tcx> {
pub predicates: Vec<Unnormalized<'tcx, Clause<'tcx>>>,
pub spans: Vec<Span>,
}
impl<'tcx> InstantiatedPredicates<'tcx> {
pub fn empty() -> InstantiatedPredicates<'tcx> {
InstantiatedPredicates { predicates: vec![], spans: vec![] }
}
pub fn is_empty(&self) -> bool {
self.predicates.is_empty()
}
pub fn iter(&self) -> <&Self as IntoIterator>::IntoIter {
self.into_iter()
}
}
impl<'tcx> IntoIterator for InstantiatedPredicates<'tcx> {
type Item = (Unnormalized<'tcx, Clause<'tcx>>, Span);
type IntoIter = std::iter::Zip<
std::vec::IntoIter<Unnormalized<'tcx, Clause<'tcx>>>,
std::vec::IntoIter<Span>,
>;
fn into_iter(self) -> Self::IntoIter {
debug_assert_eq!(self.predicates.len(), self.spans.len());
std::iter::zip(self.predicates, self.spans)
}
}
impl<'a, 'tcx> IntoIterator for &'a InstantiatedPredicates<'tcx> {
type Item = (Unnormalized<'tcx, Clause<'tcx>>, Span);
type IntoIter = std::iter::Zip<
std::iter::Copied<std::slice::Iter<'a, Unnormalized<'tcx, Clause<'tcx>>>>,
std::iter::Copied<std::slice::Iter<'a, Span>>,
>;
fn into_iter(self) -> Self::IntoIter {
debug_assert_eq!(self.predicates.len(), self.spans.len());
std::iter::zip(self.predicates.iter().copied(), self.spans.iter().copied())
}
}
#[derive(Copy, Clone, Debug, TypeFoldable, TypeVisitable, StableHash, TyEncodable, TyDecodable)]
pub struct ProvisionalHiddenType<'tcx> {
/// The span of this particular definition of the opaque type. So
/// for example:
///
/// ```ignore (incomplete snippet)
/// type Foo = impl Baz;
/// fn bar() -> Foo {
/// // ^^^ This is the span we are looking for!
/// }
/// ```
///
/// In cases where the fn returns `(impl Trait, impl Trait)` or
/// other such combinations, the result is currently
/// over-approximated, but better than nothing.
pub span: Span,
/// The type variable that represents the value of the opaque type
/// that we require. In other words, after we compile this function,
/// we will be created a constraint like:
/// ```ignore (pseudo-rust)
/// Foo<'a, T> = ?C
/// ```
/// where `?C` is the value of this type variable. =) It may
/// naturally refer to the type and lifetime parameters in scope
/// in this function, though ultimately it should only reference
/// those that are arguments to `Foo` in the constraint above. (In
/// other words, `?C` should not include `'b`, even though it's a
/// lifetime parameter on `foo`.)
pub ty: Ty<'tcx>,
}
/// Whether we're currently in HIR typeck or MIR borrowck.
#[derive(Debug, Clone, Copy)]
pub enum DefiningScopeKind {
/// During writeback in typeck, we don't care about regions and simply
/// erase them. This means we also don't check whether regions are
/// universal in the opaque type key. This will only be checked in
/// MIR borrowck.
HirTypeck,
MirBorrowck,
}
impl<'tcx> ProvisionalHiddenType<'tcx> {
pub fn new_error(tcx: TyCtxt<'tcx>, guar: ErrorGuaranteed) -> ProvisionalHiddenType<'tcx> {
ProvisionalHiddenType { span: DUMMY_SP, ty: Ty::new_error(tcx, guar) }
}
pub fn build_mismatch_error(
&self,
other: &Self,
tcx: TyCtxt<'tcx>,
) -> Result<Diag<'tcx>, ErrorGuaranteed> {
(self.ty, other.ty).error_reported()?;
// Found different concrete types for the opaque type.
let sub_diag = if self.span == other.span {
TypeMismatchReason::ConflictType { span: self.span }
} else {
TypeMismatchReason::PreviousUse { span: self.span }
};
Ok(tcx.dcx().create_err(OpaqueHiddenTypeMismatch {
self_ty: self.ty,
other_ty: other.ty,
other_span: other.span,
sub: sub_diag,
}))
}
#[instrument(level = "debug", skip(tcx), ret)]
pub fn remap_generic_params_to_declaration_params(
self,
opaque_type_key: OpaqueTypeKey<'tcx>,
tcx: TyCtxt<'tcx>,
defining_scope_kind: DefiningScopeKind,
) -> DefinitionSiteHiddenType<'tcx> {
let OpaqueTypeKey { def_id, args } = opaque_type_key;
// Use args to build up a reverse map from regions to their
// identity mappings. This is necessary because of `impl
// Trait` lifetimes are computed by replacing existing
// lifetimes with 'static and remapping only those used in the
// `impl Trait` return type, resulting in the parameters
// shifting.
let id_args = GenericArgs::identity_for_item(tcx, def_id);
debug!(?id_args);
// This zip may have several times the same lifetime in `args` paired with a different
// lifetime from `id_args`. Simply `collect`ing the iterator is the correct behaviour:
// it will pick the last one, which is the one we introduced in the impl-trait desugaring.
let map = args.iter().zip(id_args).collect();
debug!("map = {:#?}", map);
// Convert the type from the function into a type valid outside by mapping generic
// parameters to into the context of the opaque.
//
// We erase regions when doing this during HIR typeck. We manually use `fold_regions`
// here as we do not want to anonymize bound variables.
let ty = match defining_scope_kind {
DefiningScopeKind::HirTypeck => {
fold_regions(tcx, self.ty, |_, _| tcx.lifetimes.re_erased)
}
DefiningScopeKind::MirBorrowck => self.ty,
};
let result_ty = ty.fold_with(&mut opaque_types::ReverseMapper::new(tcx, map, self.span));
if cfg!(debug_assertions) && matches!(defining_scope_kind, DefiningScopeKind::HirTypeck) {
assert_eq!(result_ty, fold_regions(tcx, result_ty, |_, _| tcx.lifetimes.re_erased));
}
DefinitionSiteHiddenType { span: self.span, ty: ty::EarlyBinder::bind(tcx, result_ty) }
}
}
#[derive(Copy, Clone, Debug, StableHash, TyEncodable, TyDecodable)]
pub struct DefinitionSiteHiddenType<'tcx> {
/// The span of the definition of the opaque type. So for example:
///
/// ```ignore (incomplete snippet)
/// type Foo = impl Baz;
/// fn bar() -> Foo {
/// // ^^^ This is the span we are looking for!
/// }
/// ```
///
/// In cases where the fn returns `(impl Trait, impl Trait)` or
/// other such combinations, the result is currently
/// over-approximated, but better than nothing.
pub span: Span,
/// The final type of the opaque.
pub ty: ty::EarlyBinder<'tcx, Ty<'tcx>>,
}
impl<'tcx> DefinitionSiteHiddenType<'tcx> {
pub fn new_error(tcx: TyCtxt<'tcx>, guar: ErrorGuaranteed) -> DefinitionSiteHiddenType<'tcx> {
DefinitionSiteHiddenType {
span: DUMMY_SP,
ty: ty::EarlyBinder::bind(tcx, Ty::new_error(tcx, guar)),
}
}
pub fn build_mismatch_error(
&self,
other: &Self,
tcx: TyCtxt<'tcx>,
) -> Result<Diag<'tcx>, ErrorGuaranteed> {
let self_ty = self.ty.instantiate_identity().skip_norm_wip();
let other_ty = other.ty.instantiate_identity().skip_norm_wip();
(self_ty, other_ty).error_reported()?;
// Found different concrete types for the opaque type.
let sub_diag = if self.span == other.span {
TypeMismatchReason::ConflictType { span: self.span }
} else {
TypeMismatchReason::PreviousUse { span: self.span }
};
Ok(tcx.dcx().create_err(OpaqueHiddenTypeMismatch {
self_ty,
other_ty,
other_span: other.span,
sub: sub_diag,
}))
}
}
pub type Clauses<'tcx> = &'tcx ListWithCachedTypeInfo<Clause<'tcx>>;
impl<'tcx> rustc_type_ir::Flags for Clauses<'tcx> {
fn flags(&self) -> TypeFlags {
(**self).flags()
}
fn outer_exclusive_binder(&self) -> DebruijnIndex {
(**self).outer_exclusive_binder()
}
}
/// When interacting with the type system we must provide information about the
/// environment. `ParamEnv` is the type that represents this information. See the
/// [dev guide chapter][param_env_guide] for more information.
///
/// [param_env_guide]: https://rustc-dev-guide.rust-lang.org/typing_parameter_envs.html
#[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
#[derive(StableHash, TypeVisitable, TypeFoldable)]
pub struct ParamEnv<'tcx> {
/// Caller bounds are `Obligation`s that the caller must satisfy. This is
/// basically the set of bounds on the in-scope type parameters, translated
/// into `Obligation`s, and elaborated and normalized.
///
/// Use the `caller_bounds()` method to access.
caller_bounds: Clauses<'tcx>,
}
impl<'tcx> rustc_type_ir::inherent::ParamEnv<TyCtxt<'tcx>> for ParamEnv<'tcx> {
fn caller_bounds(self) -> impl inherent::SliceLike<Item = ty::Clause<'tcx>> {
self.caller_bounds()
}
}
impl<'tcx> ParamEnv<'tcx> {
/// Construct a trait environment suitable for contexts where there are
/// no where-clauses in scope. In the majority of cases it is incorrect
/// to use an empty environment. See the [dev guide section][param_env_guide]
/// for information on what a `ParamEnv` is and how to acquire one.
///
/// [param_env_guide]: https://rustc-dev-guide.rust-lang.org/typing_parameter_envs.html
#[inline]
pub fn empty() -> Self {
Self::new(ListWithCachedTypeInfo::empty())
}
#[inline]
pub fn caller_bounds(self) -> Clauses<'tcx> {
self.caller_bounds
}
/// Construct a trait environment with the given set of predicates.
#[inline]
pub fn new(caller_bounds: Clauses<'tcx>) -> Self {
ParamEnv { caller_bounds }
}
/// Creates a pair of param-env and value for use in queries.
pub fn and<T: TypeVisitable<TyCtxt<'tcx>>>(self, value: T) -> ParamEnvAnd<'tcx, T> {
ParamEnvAnd { param_env: self, value }
}
/// Eagerly reveal all opaque types in the `param_env`.
pub fn with_normalized(self, tcx: TyCtxt<'tcx>) -> ParamEnv<'tcx> {
// No need to reveal opaques with the new solver enabled,
// since we have lazy norm.
if tcx.next_trait_solver_globally() {
self
} else {
ParamEnv::new(tcx.reveal_opaque_types_in_bounds(self.caller_bounds))
}
}
}
#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, TypeFoldable, TypeVisitable)]
#[derive(StableHash)]
pub struct ParamEnvAnd<'tcx, T> {
pub param_env: ParamEnv<'tcx>,
pub value: T,
}
/// The environment in which to do trait solving.
///
/// Most of the time you only need to care about the `ParamEnv`
/// as the `TypingMode` is simply stored in the `InferCtxt`.
///
/// However, there are some places which rely on trait solving
/// without using an `InferCtxt` themselves. For these to be
/// able to use the trait system they have to be able to initialize
/// such an `InferCtxt` with the right `typing_mode`, so they need
/// to track both.
#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, StableHash)]
#[derive(TypeVisitable, TypeFoldable)]
pub struct TypingEnv<'tcx> {
#[type_foldable(identity)]
#[type_visitable(ignore)]
typing_mode: TypingModeEqWrapper<'tcx>,
pub param_env: ParamEnv<'tcx>,
}
impl<'tcx> TypingEnv<'tcx> {
pub fn new(param_env: ParamEnv<'tcx>, typing_mode: TypingMode<'tcx>) -> Self {
Self { typing_mode: TypingModeEqWrapper(typing_mode), param_env }
}
pub fn typing_mode(&self) -> TypingMode<'tcx> {
self.typing_mode.0
}
/// Create a typing environment with no where-clauses in scope
/// where all opaque types and default associated items are revealed.
///
/// This is only suitable for monomorphized, post-typeck environments.
/// Do not use this for MIR optimizations, as even though they also
/// use `TypingMode::PostAnalysis`, they may still have where-clauses
/// in scope.
pub fn fully_monomorphized() -> TypingEnv<'tcx> {
Self::new(ParamEnv::empty(), TypingMode::Codegen)
}
/// Create a typing environment for use during analysis outside of a body.
///
/// Using a typing environment inside of bodies is not supported as the body
/// may define opaque types. In this case the used functions have to be
/// converted to use proper canonical inputs instead.
pub fn non_body_analysis(
tcx: TyCtxt<'tcx>,
def_id: impl IntoQueryKey<DefId>,
) -> TypingEnv<'tcx> {
let def_id = def_id.into_query_key();
Self::new(tcx.param_env(def_id), TypingMode::non_body_analysis())
}
pub fn post_analysis(tcx: TyCtxt<'tcx>, def_id: impl IntoQueryKey<DefId>) -> TypingEnv<'tcx> {
TypingEnv::new(tcx.param_env_normalized_for_post_analysis(def_id), TypingMode::PostAnalysis)
}
pub fn codegen(tcx: TyCtxt<'tcx>, def_id: impl IntoQueryKey<DefId>) -> TypingEnv<'tcx> {
TypingEnv::new(tcx.param_env_normalized_for_post_analysis(def_id), TypingMode::Codegen)
}
/// Modify the `typing_mode` to `PostAnalysis` or `Codegen` and eagerly reveal all opaque types
/// in the `param_env`.
pub fn with_post_analysis_normalized(self, tcx: TyCtxt<'tcx>) -> TypingEnv<'tcx> {
let TypingEnv { typing_mode, param_env } = self;
match typing_mode.0.assert_not_erased() {
TypingMode::Coherence
| TypingMode::Typeck { .. }
| TypingMode::PostTypeckUntilBorrowck { .. }
| TypingMode::PostBorrowck { .. } => {}
TypingMode::PostAnalysis | TypingMode::Codegen => return self,
}
let param_env = param_env.with_normalized(tcx);
TypingEnv::new(param_env, TypingMode::PostAnalysis)
}
/// Modify the `typing_mode` to `PostAnalysis` or `Codegen` and eagerly reveal all opaque types
/// in the `param_env`.
pub fn with_codegen_normalized(self, tcx: TyCtxt<'tcx>) -> TypingEnv<'tcx> {
let TypingEnv { typing_mode, param_env } = self;
match typing_mode.0.assert_not_erased() {
TypingMode::Coherence
| TypingMode::Typeck { .. }
| TypingMode::PostTypeckUntilBorrowck { .. }
| TypingMode::PostBorrowck { .. }
| TypingMode::PostAnalysis => {}
TypingMode::Codegen => return self,
}
let param_env = param_env.with_normalized(tcx);
TypingEnv::new(param_env, TypingMode::Codegen)
}
/// Combine this typing environment with the given `value` to be used by
/// not (yet) canonicalized queries. This only works if the value does not
/// contain anything local to some `InferCtxt`, i.e. inference variables or
/// placeholders.
pub fn as_query_input<T>(self, value: T) -> PseudoCanonicalInput<'tcx, T>
where
T: TypeVisitable<TyCtxt<'tcx>>,
{
// FIXME(#132279): We should assert that the value does not contain any placeholders
// as these placeholders are also local to the current inference context. However, we
// currently use pseudo-canonical queries in the trait solver, which replaces params
// with placeholders during canonicalization. We should also simply not use pseudo-
// canonical queries in the trait solver, at which point we can readd this assert.
//
// As of writing this comment, this is only used when normalizing consts that mention
// params.
/* debug_assert!(
!value.has_placeholders(),
"{value:?} which has placeholder shouldn't be pseudo-canonicalized"
); */
PseudoCanonicalInput { typing_env: self, value }
}
}
/// Similar to `CanonicalInput`, this carries the `typing_mode` and the environment
/// necessary to do any kind of trait solving inside of nested queries.
///
/// Unlike proper canonicalization, this requires the `param_env` and the `value` to not
/// contain anything local to the `infcx` of the caller, so we don't actually canonicalize
/// anything.
///
/// This should be created by using `infcx.pseudo_canonicalize_query(param_env, value)`
/// or by using `typing_env.as_query_input(value)`.
#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
#[derive(StableHash, TypeVisitable, TypeFoldable)]
pub struct PseudoCanonicalInput<'tcx, T> {
pub typing_env: TypingEnv<'tcx>,
pub value: T,
}
#[derive(Copy, Clone, Debug, StableHash, Encodable, Decodable)]
pub struct Destructor {
/// The `DefId` of the destructor method
pub did: DefId,
}
// FIXME: consider combining this definition with regular `Destructor`
#[derive(Copy, Clone, Debug, StableHash, Encodable, Decodable)]
pub struct AsyncDestructor {
/// The `DefId` of the `impl AsyncDrop`
pub impl_did: DefId,
}
#[derive(Clone, Copy, PartialEq, Eq, StableHash, TyEncodable, TyDecodable)]
pub struct VariantFlags(u8);
bitflags::bitflags! {
impl VariantFlags: u8 {
const NO_VARIANT_FLAGS = 0;
/// Indicates whether the field list of this variant is `#[non_exhaustive]`.
const IS_FIELD_LIST_NON_EXHAUSTIVE = 1 << 0;
}
}
rustc_data_structures::external_bitflags_debug! { VariantFlags }
/// Definition of a variant -- a struct's fields or an enum variant.
#[derive(Debug, StableHash, TyEncodable, TyDecodable)]
pub struct VariantDef {
/// `DefId` that identifies the variant itself.
/// If this variant belongs to a struct or union, then this is a copy of its `DefId`.
pub def_id: DefId,
/// `DefId` that identifies the variant's constructor.
/// If this variant is a struct variant, then this is `None`.
pub ctor: Option<(CtorKind, DefId)>,
/// Variant or struct name.
pub name: Symbol,
/// Discriminant of this variant.
pub discr: VariantDiscr,
/// Fields of this variant.
pub fields: IndexVec<FieldIdx, FieldDef>,
/// The error guarantees from parser, if any.
tainted: Option<ErrorGuaranteed>,
/// Flags of the variant (e.g. is field list non-exhaustive)?
flags: VariantFlags,
}
impl VariantDef {
/// Creates a new `VariantDef`.
///
/// `variant_did` is the `DefId` that identifies the enum variant (if this `VariantDef`
/// represents an enum variant).
///
/// `ctor_did` is the `DefId` that identifies the constructor of unit or
/// tuple-variants/structs. If this is a `struct`-variant then this should be `None`.
///
/// `parent_did` is the `DefId` of the `AdtDef` representing the enum or struct that
/// owns this variant. It is used for checking if a struct has `#[non_exhaustive]` w/out having
/// to go through the redirect of checking the ctor's attributes - but compiling a small crate
/// requires loading the `AdtDef`s for all the structs in the universe (e.g., coherence for any
/// built-in trait), and we do not want to load attributes twice.
///
/// If someone speeds up attribute loading to not be a performance concern, they can
/// remove this hack and use the constructor `DefId` everywhere.
#[instrument(level = "debug")]
pub fn new(
name: Symbol,
variant_did: Option<DefId>,
ctor: Option<(CtorKind, DefId)>,
discr: VariantDiscr,
fields: IndexVec<FieldIdx, FieldDef>,
parent_did: DefId,
recover_tainted: Option<ErrorGuaranteed>,
is_field_list_non_exhaustive: bool,
) -> Self {
let mut flags = VariantFlags::NO_VARIANT_FLAGS;
if is_field_list_non_exhaustive {
flags |= VariantFlags::IS_FIELD_LIST_NON_EXHAUSTIVE;
}
VariantDef {
def_id: variant_did.unwrap_or(parent_did),
ctor,
name,
discr,
fields,
flags,
tainted: recover_tainted,
}
}
/// Returns `true` if the field list of this variant is `#[non_exhaustive]`.
///
/// Note that this function will return `true` even if the type has been
/// defined in the crate currently being compiled. If that's not what you
/// want, see [`Self::field_list_has_applicable_non_exhaustive`].
#[inline]
pub fn is_field_list_non_exhaustive(&self) -> bool {
self.flags.intersects(VariantFlags::IS_FIELD_LIST_NON_EXHAUSTIVE)
}
/// Returns `true` if the field list of this variant is `#[non_exhaustive]`
/// and the type has been defined in another crate.
#[inline]
pub fn field_list_has_applicable_non_exhaustive(&self) -> bool {
self.is_field_list_non_exhaustive() && !self.def_id.is_local()
}
/// Computes the `Ident` of this variant by looking up the `Span`
pub fn ident(&self, tcx: TyCtxt<'_>) -> Ident {
Ident::new(self.name, tcx.def_ident_span(self.def_id).unwrap())
}
/// Was this variant obtained as part of recovering from a syntactic error?
#[inline]
pub fn has_errors(&self) -> Result<(), ErrorGuaranteed> {
self.tainted.map_or(Ok(()), Err)
}
#[inline]
pub fn ctor_kind(&self) -> Option<CtorKind> {
self.ctor.map(|(kind, _)| kind)
}
#[inline]
pub fn ctor_def_id(&self) -> Option<DefId> {
self.ctor.map(|(_, def_id)| def_id)
}
/// Returns the one field in this variant.
///
/// `panic!`s if there are no fields or multiple fields.
#[inline]
pub fn single_field(&self) -> &FieldDef {
assert!(self.fields.len() == 1);
&self.fields[FieldIdx::ZERO]
}
/// Returns the last field in this variant, if present.
#[inline]
pub fn tail_opt(&self) -> Option<&FieldDef> {
self.fields.raw.last()
}
/// Returns the last field in this variant.
///
/// # Panics
///
/// Panics, if the variant has no fields.
#[inline]
pub fn tail(&self) -> &FieldDef {
self.tail_opt().expect("expected unsized ADT to have a tail field")
}
/// Returns whether this variant has unsafe fields.
pub fn has_unsafe_fields(&self) -> bool {
self.fields.iter().any(|x| x.safety.is_unsafe())
}
}
impl PartialEq for VariantDef {
#[inline]
fn eq(&self, other: &Self) -> bool {
// There should be only one `VariantDef` for each `def_id`, therefore
// it is fine to implement `PartialEq` only based on `def_id`.
//
// Below, we exhaustively destructure `self` and `other` so that if the
// definition of `VariantDef` changes, a compile-error will be produced,
// reminding us to revisit this assumption.
let Self {
def_id: lhs_def_id,
ctor: _,
name: _,
discr: _,
fields: _,
flags: _,
tainted: _,
} = &self;
let Self {
def_id: rhs_def_id,
ctor: _,
name: _,
discr: _,
fields: _,
flags: _,
tainted: _,
} = other;
let res = lhs_def_id == rhs_def_id;
// Double check that implicit assumption detailed above.
if cfg!(debug_assertions) && res {
let deep = self.ctor == other.ctor
&& self.name == other.name
&& self.discr == other.discr
&& self.fields == other.fields
&& self.flags == other.flags;
assert!(deep, "VariantDef for the same def-id has differing data");
}
res
}
}
impl Eq for VariantDef {}
impl Hash for VariantDef {
#[inline]
fn hash<H: Hasher>(&self, s: &mut H) {
// There should be only one `VariantDef` for each `def_id`, therefore
// it is fine to implement `Hash` only based on `def_id`.
//
// Below, we exhaustively destructure `self` so that if the definition
// of `VariantDef` changes, a compile-error will be produced, reminding
// us to revisit this assumption.
let Self { def_id, ctor: _, name: _, discr: _, fields: _, flags: _, tainted: _ } = &self;
def_id.hash(s)
}
}
#[derive(Copy, Clone, Debug, PartialEq, Eq, TyEncodable, TyDecodable, StableHash)]
pub enum VariantDiscr {
/// Explicit value for this variant, i.e., `X = 123`.
/// The `DefId` corresponds to the embedded constant.
Explicit(DefId),
/// The previous variant's discriminant plus one.
/// For efficiency reasons, the distance from the
/// last `Explicit` discriminant is being stored,
/// or `0` for the first variant, if it has none.
Relative(u32),
}
#[derive(Debug, StableHash, TyEncodable, TyDecodable)]
pub struct FieldDef {
pub did: DefId,
pub name: Symbol,
pub vis: Visibility<DefId>,
pub safety: hir::Safety,
pub value: Option<DefId>,
}
impl PartialEq for FieldDef {
#[inline]
fn eq(&self, other: &Self) -> bool {
// There should be only one `FieldDef` for each `did`, therefore it is
// fine to implement `PartialEq` only based on `did`.
//
// Below, we exhaustively destructure `self` so that if the definition
// of `FieldDef` changes, a compile-error will be produced, reminding
// us to revisit this assumption.
let Self { did: lhs_did, name: _, vis: _, safety: _, value: _ } = &self;
let Self { did: rhs_did, name: _, vis: _, safety: _, value: _ } = other;
let res = lhs_did == rhs_did;
// Double check that implicit assumption detailed above.
if cfg!(debug_assertions) && res {
let deep =
self.name == other.name && self.vis == other.vis && self.safety == other.safety;
assert!(deep, "FieldDef for the same def-id has differing data");
}
res
}
}
impl Eq for FieldDef {}
impl Hash for FieldDef {
#[inline]
fn hash<H: Hasher>(&self, s: &mut H) {
// There should be only one `FieldDef` for each `did`, therefore it is
// fine to implement `Hash` only based on `did`.
//
// Below, we exhaustively destructure `self` so that if the definition
// of `FieldDef` changes, a compile-error will be produced, reminding
// us to revisit this assumption.
let Self { did, name: _, vis: _, safety: _, value: _ } = &self;
did.hash(s)
}
}
impl<'tcx> FieldDef {
/// Returns the type of this field. The `args` are typically obtained via
/// the second field of [`TyKind::Adt`].
pub fn ty(
&self,
tcx: TyCtxt<'tcx>,
args: GenericArgsRef<'tcx>,
) -> Unnormalized<'tcx, Ty<'tcx>> {
tcx.type_of(self.did).instantiate(tcx, args)
}
/// Computes the `Ident` of this variant by looking up the `Span`
pub fn ident(&self, tcx: TyCtxt<'_>) -> Ident {
Ident::new(self.name, tcx.def_ident_span(self.did).unwrap())
}
}
#[derive(Debug, PartialEq, Eq)]
pub enum ImplOverlapKind {
/// These impls are always allowed to overlap.
Permitted {
/// Whether or not the impl is permitted due to the trait being a `#[marker]` trait
marker: bool,
},
}
/// Useful source information about where a desugared associated type for an
/// RPITIT originated from.
#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, Encodable, Decodable, StableHash)]
pub enum ImplTraitInTraitData {
Trait { fn_def_id: DefId, opaque_def_id: DefId },
Impl { fn_def_id: DefId },
}
impl<'tcx> TyCtxt<'tcx> {
pub fn typeck_body(self, body: hir::BodyId) -> &'tcx TypeckResults<'tcx> {
self.typeck(self.hir_body_owner_def_id(body))
}
pub fn provided_trait_methods(self, id: DefId) -> impl 'tcx + Iterator<Item = &'tcx AssocItem> {
self.associated_items(id)
.in_definition_order()
.filter(move |item| item.is_fn() && item.defaultness(self).has_value())
}
pub fn repr_options_of_def(self, did: LocalDefId) -> ReprOptions {
let mut flags = ReprFlags::empty();
let mut size = None;
let mut max_align: Option<Align> = None;
let mut min_pack: Option<Align> = None;
// Generate a deterministically-derived seed from the item's path hash
// to allow for cross-crate compilation to actually work
let mut field_shuffle_seed = self.def_path_hash(did.to_def_id()).0.to_smaller_hash();
// If the user defined a custom seed for layout randomization, xor the item's
// path hash with the user defined seed, this will allowing determinism while
// still allowing users to further randomize layout generation for e.g. fuzzing
if let Some(user_seed) = self.sess.opts.unstable_opts.layout_seed {
field_shuffle_seed ^= user_seed;
}
let elt = find_attr!(self, did, RustcScalableVector { element_count } => element_count
)
.map(|elt| match elt {
Some(n) => ScalableElt::ElementCount(*n),
None => ScalableElt::Container,
});
if elt.is_some() {
flags.insert(ReprFlags::IS_SCALABLE);
}
if let Some(reprs) = find_attr!(self, did, Repr { reprs, .. } => reprs) {
for (r, _) in reprs {
flags.insert(match *r {
attr::ReprRust => ReprFlags::empty(),
attr::ReprC => ReprFlags::IS_C,
attr::ReprPacked(pack) => {
min_pack = Some(if let Some(min_pack) = min_pack {
min_pack.min(pack)
} else {
pack
});
ReprFlags::empty()
}
attr::ReprTransparent => ReprFlags::IS_TRANSPARENT,
attr::ReprSimd => ReprFlags::IS_SIMD,
attr::ReprInt(i) => {
size = Some(match i {
attr::IntType::SignedInt(x) => match x {
ast::IntTy::Isize => IntegerType::Pointer(true),
ast::IntTy::I8 => IntegerType::Fixed(Integer::I8, true),
ast::IntTy::I16 => IntegerType::Fixed(Integer::I16, true),
ast::IntTy::I32 => IntegerType::Fixed(Integer::I32, true),
ast::IntTy::I64 => IntegerType::Fixed(Integer::I64, true),
ast::IntTy::I128 => IntegerType::Fixed(Integer::I128, true),
},
attr::IntType::UnsignedInt(x) => match x {
ast::UintTy::Usize => IntegerType::Pointer(false),
ast::UintTy::U8 => IntegerType::Fixed(Integer::I8, false),
ast::UintTy::U16 => IntegerType::Fixed(Integer::I16, false),
ast::UintTy::U32 => IntegerType::Fixed(Integer::I32, false),
ast::UintTy::U64 => IntegerType::Fixed(Integer::I64, false),
ast::UintTy::U128 => IntegerType::Fixed(Integer::I128, false),
},
});
ReprFlags::empty()
}
attr::ReprAlign(align) => {
max_align = max_align.max(Some(align));
ReprFlags::empty()
}
});
}
}
// If `-Z randomize-layout` was enabled for the type definition then we can
// consider performing layout randomization
if self.sess.opts.unstable_opts.randomize_layout {
flags.insert(ReprFlags::RANDOMIZE_LAYOUT);
}
// box is special, on the one hand the compiler assumes an ordered layout, with the pointer
// always at offset zero. On the other hand we want scalar abi optimizations.
let is_box = self.is_lang_item(did.to_def_id(), LangItem::OwnedBox);
// This is here instead of layout because the choice must make it into metadata.
if is_box {
flags.insert(ReprFlags::IS_LINEAR);
}
// See `TyAndLayout::pass_indirectly_in_non_rustic_abis` for details.
if find_attr!(self, did, RustcPassIndirectlyInNonRusticAbis(..)) {
flags.insert(ReprFlags::PASS_INDIRECTLY_IN_NON_RUSTIC_ABIS);
}
ReprOptions {
int: size,
align: max_align,
pack: min_pack,
flags,
field_shuffle_seed,
scalable: elt,
}
}
/// Look up the name of a definition across crates. This does not look at HIR.
pub fn opt_item_name(self, def_id: impl IntoQueryKey<DefId>) -> Option<Symbol> {
let def_id = def_id.into_query_key();
if let Some(cnum) = def_id.as_crate_root() {
Some(self.crate_name(cnum))
} else {
let def_key = self.def_key(def_id);
match def_key.disambiguated_data.data {
// The name of a constructor is that of its parent.
rustc_hir::definitions::DefPathData::Ctor => self
.opt_item_name(DefId { krate: def_id.krate, index: def_key.parent.unwrap() }),
_ => def_key.get_opt_name(),
}
}
}
/// Look up the name of a definition across crates. This does not look at HIR.
///
/// This method will ICE if the corresponding item does not have a name. In these cases, use
/// [`opt_item_name`] instead.
///
/// [`opt_item_name`]: Self::opt_item_name
pub fn item_name(self, id: impl IntoQueryKey<DefId>) -> Symbol {
let id = id.into_query_key();
self.opt_item_name(id).unwrap_or_else(|| {
bug!("item_name: no name for {:?}", self.def_path(id));
})
}
/// Look up the name and span of a definition.
///
/// See [`item_name`][Self::item_name] for more information.
pub fn opt_item_ident(self, def_id: impl IntoQueryKey<DefId>) -> Option<Ident> {
let def_id = def_id.into_query_key();
let def = self.opt_item_name(def_id)?;
let span = self
.def_ident_span(def_id)
.unwrap_or_else(|| bug!("missing ident span for {def_id:?}"));
Some(Ident::new(def, span))
}
/// Look up the name and span of a definition.
///
/// See [`item_name`][Self::item_name] for more information.
pub fn item_ident(self, def_id: impl IntoQueryKey<DefId>) -> Ident {
let def_id = def_id.into_query_key();
self.opt_item_ident(def_id).unwrap_or_else(|| {
bug!("item_ident: no name for {:?}", self.def_path(def_id));
})
}
pub fn opt_associated_item(self, def_id: DefId) -> Option<AssocItem> {
if let DefKind::AssocConst { .. } | DefKind::AssocFn | DefKind::AssocTy =
self.def_kind(def_id)
{
Some(self.associated_item(def_id))
} else {
None
}
}
/// If the `def_id` is an associated type that was desugared from a
/// return-position `impl Trait` from a trait, then provide the source info
/// about where that RPITIT came from.
pub fn opt_rpitit_info(self, def_id: DefId) -> Option<ImplTraitInTraitData> {
if let DefKind::AssocTy = self.def_kind(def_id)
&& let AssocKind::Type { data: AssocTypeData::Rpitit(rpitit_info) } =
self.associated_item(def_id).kind
{
Some(rpitit_info)
} else {
None
}
}
pub fn find_field_index(self, ident: Ident, variant: &VariantDef) -> Option<FieldIdx> {
variant.fields.iter_enumerated().find_map(|(i, field)| {
self.hygienic_eq(ident, field.ident(self), variant.def_id).then_some(i)
})
}
/// Returns `Some` if the impls are the same polarity and the trait either
/// has no items or is annotated `#[marker]` and prevents item overrides.
#[instrument(level = "debug", skip(self), ret)]
pub fn impls_are_allowed_to_overlap(
self,
def_id1: DefId,
def_id2: DefId,
) -> Option<ImplOverlapKind> {
let impl1 = self.impl_trait_header(def_id1);
let impl2 = self.impl_trait_header(def_id2);
let trait_ref1 = impl1.trait_ref.skip_binder();
let trait_ref2 = impl2.trait_ref.skip_binder();
// If either trait impl references an error, they're allowed to overlap,
// as one of them essentially doesn't exist.
if trait_ref1.references_error() || trait_ref2.references_error() {
return Some(ImplOverlapKind::Permitted { marker: false });
}
match (impl1.polarity, impl2.polarity) {
(ImplPolarity::Reservation, _) | (_, ImplPolarity::Reservation) => {
// `#[rustc_reservation_impl]` impls don't overlap with anything
return Some(ImplOverlapKind::Permitted { marker: false });
}
(ImplPolarity::Positive, ImplPolarity::Negative)
| (ImplPolarity::Negative, ImplPolarity::Positive) => {
// `impl AutoTrait for Type` + `impl !AutoTrait for Type`
return None;
}
(ImplPolarity::Positive, ImplPolarity::Positive)
| (ImplPolarity::Negative, ImplPolarity::Negative) => {}
};
let is_marker_impl = |trait_ref: TraitRef<'_>| self.trait_def(trait_ref.def_id).is_marker;
let is_marker_overlap = is_marker_impl(trait_ref1) && is_marker_impl(trait_ref2);
if is_marker_overlap {
return Some(ImplOverlapKind::Permitted { marker: true });
}
None
}
/// Returns `ty::VariantDef` if `res` refers to a struct,
/// or variant or their constructors, panics otherwise.
pub fn expect_variant_res(self, res: Res) -> &'tcx VariantDef {
match res {
Res::Def(DefKind::Variant, did) => {
let enum_did = self.parent(did);
self.adt_def(enum_did).variant_with_id(did)
}
Res::Def(DefKind::Struct | DefKind::Union, did) => self.adt_def(did).non_enum_variant(),
Res::Def(DefKind::Ctor(CtorOf::Variant, ..), variant_ctor_did) => {
let variant_did = self.parent(variant_ctor_did);
let enum_did = self.parent(variant_did);
self.adt_def(enum_did).variant_with_ctor_id(variant_ctor_did)
}
Res::Def(DefKind::Ctor(CtorOf::Struct, ..), ctor_did) => {
let struct_did = self.parent(ctor_did);
self.adt_def(struct_did).non_enum_variant()
}
_ => bug!("expect_variant_res used with unexpected res {:?}", res),
}
}
/// Returns the possibly-auto-generated MIR of a [`ty::InstanceKind`].
#[instrument(skip(self), level = "debug")]
pub fn instance_mir(self, instance: ty::InstanceKind<'tcx>) -> &'tcx Body<'tcx> {
let body = match instance {
ty::InstanceKind::Item(def) => {
debug!("calling def_kind on def: {:?}", def);
let def_kind = self.def_kind(def);
debug!("returned from def_kind: {:?}", def_kind);
match def_kind {
DefKind::Const { .. }
| DefKind::Static { .. }
| DefKind::AssocConst { .. }
| DefKind::Ctor(..)
| DefKind::AnonConst
| DefKind::InlineConst => self.mir_for_ctfe(def),
DefKind::Fn | DefKind::AssocFn
if matches!(
self.constness(def),
hir::Constness::Const { always: true }
) =>
{
self.mir_for_ctfe(def)
}
// If the caller wants `mir_for_ctfe` of a function they should not be using
// `instance_mir`, so we'll assume const fn also wants the optimized version.
_ => self.optimized_mir(def),
}
}
ty::InstanceKind::Intrinsic(..) => bug!("intrinsics have no instance MIR"),
ty::InstanceKind::Virtual(..) => bug!("virtual dispatches have no instance MIR"),
ty::InstanceKind::Shim(shim) => self.mir_shims(shim),
};
assert!(
matches!(body.phase, MirPhase::Runtime(_)),
"body: {body:?} instance: {instance:?} {:?}",
if let ty::InstanceKind::Item(d) = instance { Some(self.def_kind(d)) } else { None },
);
body
}
/// Gets all attributes with the given name.
#[deprecated = "Though there are valid usecases for this method, especially when your attribute is not a parsed attribute, usually you want to call rustc_hir::find_attr! instead."]
pub fn get_attrs(
self,
did: impl Into<DefId>,
attr: Symbol,
) -> impl Iterator<Item = &'tcx hir::Attribute> {
#[allow(deprecated)]
self.get_all_attrs(did).iter().filter(move |a: &&hir::Attribute| a.has_name(attr))
}
/// Gets all attributes.
///
/// To see if an item has a specific attribute, you should use
/// [`rustc_hir::find_attr!`] so you can use matching.
#[deprecated = "Though there are valid usecases for this method, especially when your attribute is not a parsed attribute, usually you want to call rustc_hir::find_attr! instead."]
pub fn get_all_attrs(self, did: impl Into<DefId>) -> &'tcx [hir::Attribute] {
let did: DefId = did.into();
if let Some(did) = did.as_local() {
self.hir_attrs(self.local_def_id_to_hir_id(did))
} else {
self.attrs_for_def(did)
}
}
pub fn get_attrs_by_path(
self,
did: DefId,
attr: &[Symbol],
) -> impl Iterator<Item = &'tcx hir::Attribute> {
let filter_fn = move |a: &&hir::Attribute| a.path_matches(attr);
if let Some(did) = did.as_local() {
self.hir_attrs(self.local_def_id_to_hir_id(did)).iter().filter(filter_fn)
} else {
self.attrs_for_def(did).iter().filter(filter_fn)
}
}
/// Returns `true` if this is an `auto trait`.
pub fn trait_is_auto(self, trait_def_id: DefId) -> bool {
self.trait_def(trait_def_id).has_auto_impl
}
/// Returns `true` if this is coinductive, either because it is
/// an auto trait or because it has the `#[rustc_coinductive]` attribute.
pub fn trait_is_coinductive(self, trait_def_id: DefId) -> bool {
self.trait_def(trait_def_id).is_coinductive
}
/// Returns `true` if this is a trait alias.
pub fn trait_is_alias(self, trait_def_id: DefId) -> bool {
self.def_kind(trait_def_id) == DefKind::TraitAlias
}
/// Arena-alloc of LayoutError for coroutine layout
fn layout_error(self, err: LayoutError<'tcx>) -> &'tcx LayoutError<'tcx> {
self.arena.alloc(err)
}
/// Returns layout of a non-async-drop coroutine. Layout might be unavailable if the
/// coroutine is tainted by errors.
///
/// Takes `coroutine_kind` which can be acquired from the `CoroutineArgs::kind_ty`,
/// e.g. `args.as_coroutine().kind_ty()`.
fn ordinary_coroutine_layout(
self,
def_id: DefId,
args: GenericArgsRef<'tcx>,
) -> Result<&'tcx CoroutineLayout<'tcx>, &'tcx LayoutError<'tcx>> {
let coroutine_kind_ty = args.as_coroutine().kind_ty();
let mir = self.optimized_mir(def_id);
let ty = || Ty::new_coroutine(self, def_id, args);
// Regular coroutine
if coroutine_kind_ty.is_unit() {
mir.coroutine_layout_raw().ok_or_else(|| self.layout_error(LayoutError::Unknown(ty())))
} else {
// If we have a `Coroutine` that comes from an coroutine-closure,
// then it may be a by-move or by-ref body.
let ty::Coroutine(_, identity_args) =
*self.type_of(def_id).instantiate_identity().skip_norm_wip().kind()
else {
unreachable!();
};
let identity_kind_ty = identity_args.as_coroutine().kind_ty();
// If the types differ, then we must be getting the by-move body of
// a by-ref coroutine.
if identity_kind_ty == coroutine_kind_ty {
mir.coroutine_layout_raw()
.ok_or_else(|| self.layout_error(LayoutError::Unknown(ty())))
} else {
assert_matches!(coroutine_kind_ty.to_opt_closure_kind(), Some(ClosureKind::FnOnce));
assert_matches!(
identity_kind_ty.to_opt_closure_kind(),
Some(ClosureKind::Fn | ClosureKind::FnMut)
);
self.optimized_mir(self.coroutine_by_move_body_def_id(def_id))
.coroutine_layout_raw()
.ok_or_else(|| self.layout_error(LayoutError::Unknown(ty())))
}
}
}
/// Returns layout of a `async_drop_in_place::{closure}` coroutine
/// (returned from `async fn async_drop_in_place<T>(..)`).
/// Layout might be unavailable if the coroutine is tainted by errors.
fn async_drop_coroutine_layout(
self,
def_id: DefId,
args: GenericArgsRef<'tcx>,
) -> Result<&'tcx CoroutineLayout<'tcx>, &'tcx LayoutError<'tcx>> {
let ty = || Ty::new_coroutine(self, def_id, args);
if args[0].has_placeholders() || args[0].has_non_region_param() {
return Err(self.layout_error(LayoutError::TooGeneric(ty())));
}
let instance = ShimKind::AsyncDropGlue(def_id, Ty::new_coroutine(self, def_id, args));
self.mir_shims(instance)
.coroutine_layout_raw()
.ok_or_else(|| self.layout_error(LayoutError::Unknown(ty())))
}
/// Returns layout of a coroutine. Layout might be unavailable if the
/// coroutine is tainted by errors.
pub fn coroutine_layout(
self,
def_id: DefId,
args: GenericArgsRef<'tcx>,
) -> Result<&'tcx CoroutineLayout<'tcx>, &'tcx LayoutError<'tcx>> {
if self.is_async_drop_in_place_coroutine(def_id) {
// layout of `async_drop_in_place<T>::{closure}` in case,
// when T is a coroutine, contains this internal coroutine's ptr in upvars
// and doesn't require any locals. Here is an `empty coroutine's layout`
let arg_cor_ty = args.first().unwrap().expect_ty();
if arg_cor_ty.is_coroutine() {
let span = self.def_span(def_id);
let source_info = SourceInfo::outermost(span);
// Even minimal, empty coroutine has 3 states (RESERVED_VARIANTS),
// so variant_fields and variant_source_info should have 3 elements.
let variant_fields: IndexVec<VariantIdx, IndexVec<FieldIdx, CoroutineSavedLocal>> =
iter::repeat(IndexVec::new()).take(CoroutineArgs::RESERVED_VARIANTS).collect();
let variant_source_info: IndexVec<VariantIdx, SourceInfo> =
iter::repeat(source_info).take(CoroutineArgs::RESERVED_VARIANTS).collect();
let proxy_layout = CoroutineLayout {
field_tys: [].into(),
variant_fields,
variant_source_info,
storage_conflicts: BitMatrix::new(0, 0),
};
return Ok(self.arena.alloc(proxy_layout));
} else {
self.async_drop_coroutine_layout(def_id, args)
}
} else {
self.ordinary_coroutine_layout(def_id, args)
}
}
/// If the given `DefId` is an associated item, returns the `DefId` and `DefKind` of the parent trait or impl.
pub fn assoc_parent(self, def_id: DefId) -> Option<(DefId, DefKind)> {
if !self.def_kind(def_id).is_assoc() {
return None;
}
let parent = self.parent(def_id);
let def_kind = self.def_kind(parent);
Some((parent, def_kind))
}
/// Returns the trait item that is implemented by the given item `DefId`.
pub fn trait_item_of(self, def_id: impl IntoQueryKey<DefId>) -> Option<DefId> {
let def_id = def_id.into_query_key();
self.opt_associated_item(def_id)?.trait_item_def_id()
}
/// If the given `DefId` is an associated item of a trait,
/// returns the `DefId` of the trait; otherwise, returns `None`.
pub fn trait_of_assoc(self, def_id: DefId) -> Option<DefId> {
match self.assoc_parent(def_id) {
Some((id, DefKind::Trait)) => Some(id),
_ => None,
}
}
pub fn impl_is_of_trait(self, def_id: impl IntoQueryKey<DefId>) -> bool {
let def_id = def_id.into_query_key();
let DefKind::Impl { of_trait } = self.def_kind(def_id) else {
panic!("expected Impl for {def_id:?}");
};
of_trait
}
/// If the given `DefId` is an associated item of an impl,
/// returns the `DefId` of the impl; otherwise returns `None`.
pub fn impl_of_assoc(self, def_id: DefId) -> Option<DefId> {
match self.assoc_parent(def_id) {
Some((id, DefKind::Impl { .. })) => Some(id),
_ => None,
}
}
/// If the given `DefId` is an associated item of an inherent impl,
/// returns the `DefId` of the impl; otherwise, returns `None`.
pub fn inherent_impl_of_assoc(self, def_id: DefId) -> Option<DefId> {
match self.assoc_parent(def_id) {
Some((id, DefKind::Impl { of_trait: false })) => Some(id),
_ => None,
}
}
/// If the given `DefId` is an associated item of a trait impl,
/// returns the `DefId` of the impl; otherwise, returns `None`.
pub fn trait_impl_of_assoc(self, def_id: DefId) -> Option<DefId> {
match self.assoc_parent(def_id) {
Some((id, DefKind::Impl { of_trait: true })) => Some(id),
_ => None,
}
}
pub fn impl_polarity(self, def_id: impl IntoQueryKey<DefId>) -> ty::ImplPolarity {
let def_id = def_id.into_query_key();
self.impl_trait_header(def_id).polarity
}
/// Given an `impl_id`, return the trait it implements.
pub fn impl_trait_ref(
self,
def_id: impl IntoQueryKey<DefId>,
) -> ty::EarlyBinder<'tcx, ty::TraitRef<'tcx>> {
let def_id = def_id.into_query_key();
self.impl_trait_header(def_id).trait_ref
}
/// Given an `impl_id`, return the trait it implements.
/// Returns `None` if it is an inherent impl.
pub fn impl_opt_trait_ref(
self,
def_id: impl IntoQueryKey<DefId>,
) -> Option<ty::EarlyBinder<'tcx, ty::TraitRef<'tcx>>> {
let def_id = def_id.into_query_key();
self.impl_is_of_trait(def_id).then(|| self.impl_trait_ref(def_id))
}
/// Given the `DefId` of an impl, returns the `DefId` of the trait it implements.
pub fn impl_trait_id(self, def_id: impl IntoQueryKey<DefId>) -> DefId {
let def_id = def_id.into_query_key();
self.impl_trait_ref(def_id).skip_binder().def_id
}
/// Given the `DefId` of an impl, returns the `DefId` of the trait it implements.
/// Returns `None` if it is an inherent impl.
pub fn impl_opt_trait_id(self, def_id: impl IntoQueryKey<DefId>) -> Option<DefId> {
let def_id = def_id.into_query_key();
self.impl_is_of_trait(def_id).then(|| self.impl_trait_id(def_id))
}
pub fn is_exportable(self, def_id: DefId) -> bool {
self.exportable_items(def_id.krate).contains(&def_id)
}
/// Check if the given `DefId` is `#\[automatically_derived\]`, *and*
/// whether it was produced by expanding a builtin derive macro.
pub fn is_builtin_derived(self, def_id: DefId) -> bool {
if self.is_automatically_derived(def_id)
&& let Some(def_id) = def_id.as_local()
&& let outer = self.def_span(def_id).ctxt().outer_expn_data()
&& matches!(outer.kind, ExpnKind::Macro(MacroKind::Derive, _))
&& find_attr!(self, outer.macro_def_id.unwrap(), RustcBuiltinMacro { .. })
{
true
} else {
false
}
}
/// Check if the given `DefId` is `#\[automatically_derived\]`.
pub fn is_automatically_derived(self, def_id: DefId) -> bool {
find_attr!(self, def_id, AutomaticallyDerived)
}
/// Looks up the span of `impl_did` if the impl is local; otherwise returns `Err`
/// with the name of the crate containing the impl.
pub fn span_of_impl(self, impl_def_id: DefId) -> Result<Span, Symbol> {
if let Some(impl_def_id) = impl_def_id.as_local() {
Ok(self.def_span(impl_def_id))
} else {
Err(self.crate_name(impl_def_id.krate))
}
}
/// Hygienically compares a use-site name (`use_name`) for a field or an associated item with
/// its supposed definition name (`def_name`). The method also needs `DefId` of the supposed
/// definition's parent/scope to perform comparison.
pub fn hygienic_eq(self, use_ident: Ident, def_ident: Ident, def_parent_def_id: DefId) -> bool {
// We could use `Ident::eq` here, but we deliberately don't. The identifier
// comparison fails frequently, and we want to avoid the expensive
// `normalize_to_macros_2_0()` calls required for the span comparison whenever possible.
use_ident.name == def_ident.name
&& use_ident
.span
.ctxt()
.hygienic_eq(def_ident.span.ctxt(), self.expn_that_defined(def_parent_def_id))
}
pub fn adjust_ident(self, mut ident: Ident, scope: DefId) -> Ident {
ident.span.normalize_to_macros_2_0_and_adjust(self.expn_that_defined(scope));
ident
}
// FIXME(vincenzopalazzo): move the HirId to a LocalDefId
pub fn adjust_ident_and_get_scope(
self,
mut ident: Ident,
scope: DefId,
block: hir::HirId,
) -> (Ident, DefId) {
let scope = ident
.span
.normalize_to_macros_2_0_and_adjust(self.expn_that_defined(scope))
.and_then(|actual_expansion| actual_expansion.expn_data().parent_module)
.unwrap_or_else(|| self.parent_module(block).to_def_id());
(ident, scope)
}
/// Checks whether this is a `const fn`. Returns `false` for non-functions.
///
/// Even if this returns `true`, constness may still be unstable!
#[inline]
pub fn is_const_fn(self, def_id: impl IntoQueryKey<DefId>) -> bool {
let def_id = def_id.into_query_key();
matches!(
self.def_kind(def_id),
DefKind::Fn | DefKind::AssocFn | DefKind::Ctor(_, CtorKind::Fn) | DefKind::Closure
) && matches!(self.constness(def_id), hir::Constness::Const { .. })
}
/// Whether this item is conditionally constant for the purposes of the
/// effects implementation.
///
/// This roughly corresponds to all const functions and other callable
/// items, along with const impls and traits, and associated types within
/// those impls and traits.
pub fn is_conditionally_const(self, def_id: impl Into<DefId>) -> bool {
let def_id: DefId = def_id.into();
match self.def_kind(def_id) {
DefKind::Impl { of_trait: true } => {
let header = self.impl_trait_header(def_id);
matches!(header.constness, hir::Constness::Const { always: false })
&& self.is_const_trait(header.trait_ref.skip_binder().def_id)
}
DefKind::Impl { of_trait: false } => {
matches!(self.constness(def_id), hir::Constness::Const { always: false })
}
DefKind::Fn | DefKind::Ctor(_, CtorKind::Fn) => {
matches!(self.constness(def_id), hir::Constness::Const { always: false })
}
DefKind::TraitAlias | DefKind::Trait => self.is_const_trait(def_id),
DefKind::AssocTy => {
let parent_def_id = self.parent(def_id);
match self.def_kind(parent_def_id) {
DefKind::Impl { of_trait: false } => false,
DefKind::Impl { of_trait: true } | DefKind::Trait => {
self.is_conditionally_const(parent_def_id)
}
_ => bug!("unexpected parent item of associated type: {parent_def_id:?}"),
}
}
DefKind::AssocFn => {
let parent_def_id = self.parent(def_id);
match self.def_kind(parent_def_id) {
DefKind::Impl { of_trait: false } => {
matches!(self.constness(def_id), hir::Constness::Const { always: false })
}
DefKind::Impl { of_trait: true } => {
let Some(trait_method_did) = self.trait_item_of(def_id) else {
return false;
};
matches!(
self.constness(trait_method_did),
hir::Constness::Const { always: false }
) && self.is_conditionally_const(parent_def_id)
}
DefKind::Trait => {
matches!(self.constness(def_id), hir::Constness::Const { always: false })
&& self.is_conditionally_const(parent_def_id)
}
_ => bug!("unexpected parent item of associated fn: {parent_def_id:?}"),
}
}
DefKind::OpaqueTy => match self.opaque_ty_origin(def_id) {
hir::OpaqueTyOrigin::FnReturn { parent, .. } => self.is_conditionally_const(parent),
hir::OpaqueTyOrigin::AsyncFn { .. } => false,
// FIXME(const_trait_impl): ATPITs could be conditionally const?
hir::OpaqueTyOrigin::TyAlias { .. } => false,
},
DefKind::Closure => {
matches!(self.constness(def_id), hir::Constness::Const { always: false })
}
DefKind::Ctor(_, CtorKind::Const)
| DefKind::Mod
| DefKind::Struct
| DefKind::Union
| DefKind::Enum
| DefKind::Variant
| DefKind::TyAlias
| DefKind::ForeignTy
| DefKind::TyParam
| DefKind::Const { .. }
| DefKind::ConstParam
| DefKind::Static { .. }
| DefKind::AssocConst { .. }
| DefKind::Macro(_)
| DefKind::ExternCrate
| DefKind::Use
| DefKind::ForeignMod
| DefKind::AnonConst
| DefKind::InlineConst
| DefKind::Field
| DefKind::LifetimeParam
| DefKind::GlobalAsm
| DefKind::SyntheticCoroutineBody => false,
}
}
#[inline]
pub fn is_const_trait(self, def_id: DefId) -> bool {
matches!(self.trait_def(def_id).constness, hir::Constness::Const { .. })
}
pub fn impl_method_has_trait_impl_trait_tys(self, def_id: DefId) -> bool {
if self.def_kind(def_id) != DefKind::AssocFn {
return false;
}
let Some(item) = self.opt_associated_item(def_id) else {
return false;
};
let AssocContainer::TraitImpl(Ok(trait_item_def_id)) = item.container else {
return false;
};
!self.associated_types_for_impl_traits_in_associated_fn(trait_item_def_id).is_empty()
}
/// Compute a `FnAbi` suitable for declaring/defining an `fn` instance, and for direct calls*
/// to an `fn`. Indirectly-passed parameters in the returned ABI will include applicable
/// codegen optimization attributes, including `ReadOnly` and `CapturesNone` -- deduction of
/// which requires inspection of function bodies that can lead to cycles when performed during
/// typeck. During typeck, you should therefore use instead the unoptimized ABI returned by
/// `fn_abi_of_instance_no_deduced_attrs`.
///
/// For performance reasons, you should prefer to call this inherent method rather than invoke
/// the `fn_abi_of_instance_raw` query: it delegates to that query if necessary, but where
/// possible delegates instead to the `fn_abi_of_instance_no_deduced_attrs` query (thus avoiding
/// unnecessary query system overhead).
///
/// * that includes virtual calls, which are represented by "direct calls" to an
/// `InstanceKind::Virtual` instance (of `<dyn Trait as Trait>::fn`).
#[inline]
pub fn fn_abi_of_instance(
self,
query: ty::PseudoCanonicalInput<'tcx, (ty::Instance<'tcx>, &'tcx ty::List<Ty<'tcx>>)>,
) -> Result<&'tcx FnAbi<'tcx, Ty<'tcx>>, &'tcx FnAbiError<'tcx>> {
// Only deduce attrs in full, optimized builds. Otherwise, avoid the query system overhead
// of ever invoking the `fn_abi_of_instance_raw` query.
if self.sess.opts.optimize != OptLevel::No && self.sess.opts.incremental.is_none() {
self.fn_abi_of_instance_raw(query)
} else {
self.fn_abi_of_instance_no_deduced_attrs(query)
}
}
}
// `HasAttrs` impls: allow `find_attr!(tcx, id, ...)` to work with both DefId-like types and HirId.
impl<'tcx> hir::attrs::HasAttrs<'tcx, TyCtxt<'tcx>> for DefId {
fn get_attrs(self, tcx: &TyCtxt<'tcx>) -> &'tcx [hir::Attribute] {
if let Some(did) = self.as_local() {
tcx.hir_attrs(tcx.local_def_id_to_hir_id(did))
} else {
tcx.attrs_for_def(self)
}
}
}
impl<'tcx> hir::attrs::HasAttrs<'tcx, TyCtxt<'tcx>> for LocalDefId {
fn get_attrs(self, tcx: &TyCtxt<'tcx>) -> &'tcx [hir::Attribute] {
tcx.hir_attrs(tcx.local_def_id_to_hir_id(self))
}
}
impl<'tcx> hir::attrs::HasAttrs<'tcx, TyCtxt<'tcx>> for hir::OwnerId {
fn get_attrs(self, tcx: &TyCtxt<'tcx>) -> &'tcx [hir::Attribute] {
hir::attrs::HasAttrs::get_attrs(self.def_id, tcx)
}
}
impl<'tcx> hir::attrs::HasAttrs<'tcx, TyCtxt<'tcx>> for hir::HirId {
fn get_attrs(self, tcx: &TyCtxt<'tcx>) -> &'tcx [hir::Attribute] {
tcx.hir_attrs(self)
}
}
pub fn provide(providers: &mut Providers) {
closure::provide(providers);
context::provide(providers);
erase_regions::provide(providers);
inhabitedness::provide(providers);
util::provide(providers);
print::provide(providers);
super::util::bug::provide(providers);
*providers = Providers {
trait_impls_of: trait_def::trait_impls_of_provider,
incoherent_impls: trait_def::incoherent_impls_provider,
trait_impls_in_crate: trait_def::trait_impls_in_crate_provider,
traits: trait_def::traits_provider,
vtable_allocation: vtable::vtable_allocation_provider,
..*providers
};
}
/// A map for the local crate mapping each type to a vector of its
/// inherent impls. This is not meant to be used outside of coherence;
/// rather, you should request the vector for a specific type via
/// `tcx.inherent_impls(def_id)` so as to minimize your dependencies
/// (constructing this map requires touching the entire crate).
#[derive(Clone, Debug, Default, StableHash)]
pub struct CrateInherentImpls {
pub inherent_impls: FxIndexMap<LocalDefId, Vec<DefId>>,
pub incoherent_impls: FxIndexMap<SimplifiedType, Vec<LocalDefId>>,
}
#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, TyEncodable, StableHash)]
pub struct SymbolName<'tcx> {
/// `&str` gives a consistent ordering, which ensures reproducible builds.
pub name: &'tcx str,
}
impl<'tcx> SymbolName<'tcx> {
pub fn new(tcx: TyCtxt<'tcx>, name: &str) -> SymbolName<'tcx> {
SymbolName { name: tcx.arena.alloc_str(name) }
}
}
impl<'tcx> fmt::Display for SymbolName<'tcx> {
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Display::fmt(&self.name, fmt)
}
}
impl<'tcx> fmt::Debug for SymbolName<'tcx> {
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Display::fmt(&self.name, fmt)
}
}
/// The constituent parts of a type level constant of kind ADT or array.
#[derive(Copy, Clone, Debug, StableHash)]
pub struct DestructuredAdtConst<'tcx> {
pub variant: VariantIdx,
pub fields: &'tcx [ty::Const<'tcx>],
}