diff options
| -rw-r--r-- | compiler/rustc_middle/src/ty/adt.rs | 482 | ||||
| -rw-r--r-- | compiler/rustc_middle/src/ty/mod.rs | 473 |
2 files changed, 488 insertions, 467 deletions
diff --git a/compiler/rustc_middle/src/ty/adt.rs b/compiler/rustc_middle/src/ty/adt.rs new file mode 100644 index 00000000000..95159ea46ae --- /dev/null +++ b/compiler/rustc_middle/src/ty/adt.rs @@ -0,0 +1,482 @@ +use crate::ich::StableHashingContext; +use crate::mir::interpret::ErrorHandled; +use crate::ty; +use crate::ty::util::{Discr, IntTypeExt}; +use rustc_data_structures::captures::Captures; +use rustc_data_structures::fingerprint::Fingerprint; +use rustc_data_structures::fx::FxHashMap; +use rustc_data_structures::stable_hasher::{HashStable, StableHasher}; +use rustc_errors::ErrorReported; +use rustc_hir::def::{DefKind, Res}; +use rustc_hir::def_id::DefId; +use rustc_index::vec::{Idx, IndexVec}; +use rustc_serialize::{self, Encodable, Encoder}; +use rustc_session::DataTypeKind; +use rustc_span::symbol::sym; +use rustc_target::abi::VariantIdx; + +use std::cell::RefCell; +use std::cmp::Ordering; +use std::hash::{Hash, Hasher}; +use std::ops::Range; +use std::{ptr, str}; + +use super::{ + Destructor, FieldDef, GenericPredicates, ReprOptions, Ty, TyCtxt, VariantDef, VariantDiscr, +}; + +#[derive(Clone, HashStable, Debug)] +pub struct AdtSizedConstraint<'tcx>(pub &'tcx [Ty<'tcx>]); + +bitflags! { + #[derive(HashStable)] + pub struct AdtFlags: u32 { + const NO_ADT_FLAGS = 0; + /// Indicates whether the ADT is an enum. + const IS_ENUM = 1 << 0; + /// Indicates whether the ADT is a union. + const IS_UNION = 1 << 1; + /// Indicates whether the ADT is a struct. + const IS_STRUCT = 1 << 2; + /// Indicates whether the ADT is a struct and has a constructor. + const HAS_CTOR = 1 << 3; + /// Indicates whether the type is `PhantomData`. + const IS_PHANTOM_DATA = 1 << 4; + /// Indicates whether the type has a `#[fundamental]` attribute. + const IS_FUNDAMENTAL = 1 << 5; + /// Indicates whether the type is `Box`. + const IS_BOX = 1 << 6; + /// Indicates whether the type is `ManuallyDrop`. + const IS_MANUALLY_DROP = 1 << 7; + /// Indicates whether the variant list of this ADT is `#[non_exhaustive]`. + /// (i.e., this flag is never set unless this ADT is an enum). + const IS_VARIANT_LIST_NON_EXHAUSTIVE = 1 << 8; + } +} + +/// The definition of a user-defined type, e.g., a `struct`, `enum`, or `union`. +/// +/// These are all interned (by `alloc_adt_def`) into the global arena. +/// +/// The initialism *ADT* stands for an [*algebraic data type (ADT)*][adt]. +/// This is slightly wrong because `union`s are not ADTs. +/// Moreover, Rust only allows recursive data types through indirection. +/// +/// [adt]: https://en.wikipedia.org/wiki/Algebraic_data_type +pub struct AdtDef { + /// The `DefId` of the struct, enum or union item. + pub did: DefId, + /// Variants of the ADT. If this is a struct or union, then there will be a single variant. + pub variants: IndexVec<VariantIdx, VariantDef>, + /// Flags of the ADT (e.g., is this a struct? is this non-exhaustive?). + flags: AdtFlags, + /// Repr options provided by the user. + pub repr: ReprOptions, +} + +impl PartialOrd for AdtDef { + fn partial_cmp(&self, other: &AdtDef) -> Option<Ordering> { + Some(self.cmp(&other)) + } +} + +/// There should be only one AdtDef for each `did`, therefore +/// it is fine to implement `Ord` only based on `did`. +impl Ord for AdtDef { + fn cmp(&self, other: &AdtDef) -> Ordering { + self.did.cmp(&other.did) + } +} + +impl PartialEq for AdtDef { + // `AdtDef`s are always interned, and this is part of `TyS` equality. + #[inline] + fn eq(&self, other: &Self) -> bool { + ptr::eq(self, other) + } +} + +impl Eq for AdtDef {} + +impl Hash for AdtDef { + #[inline] + fn hash<H: Hasher>(&self, s: &mut H) { + (self as *const AdtDef).hash(s) + } +} + +impl<S: Encoder> Encodable<S> for AdtDef { + fn encode(&self, s: &mut S) -> Result<(), S::Error> { + self.did.encode(s) + } +} + +impl<'a> HashStable<StableHashingContext<'a>> for AdtDef { + fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) { + thread_local! { + static CACHE: RefCell<FxHashMap<usize, Fingerprint>> = Default::default(); + } + + let hash: Fingerprint = CACHE.with(|cache| { + let addr = self as *const AdtDef as usize; + *cache.borrow_mut().entry(addr).or_insert_with(|| { + let ty::AdtDef { did, ref variants, ref flags, ref repr } = *self; + + let mut hasher = StableHasher::new(); + did.hash_stable(hcx, &mut hasher); + variants.hash_stable(hcx, &mut hasher); + flags.hash_stable(hcx, &mut hasher); + repr.hash_stable(hcx, &mut hasher); + + hasher.finish() + }) + }); + + hash.hash_stable(hcx, hasher); + } +} + +#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)] +pub enum AdtKind { + Struct, + Union, + Enum, +} + +impl Into<DataTypeKind> for AdtKind { + fn into(self) -> DataTypeKind { + match self { + AdtKind::Struct => DataTypeKind::Struct, + AdtKind::Union => DataTypeKind::Union, + AdtKind::Enum => DataTypeKind::Enum, + } + } +} + +impl<'tcx> AdtDef { + /// Creates a new `AdtDef`. + pub(super) fn new( + tcx: TyCtxt<'_>, + did: DefId, + kind: AdtKind, + variants: IndexVec<VariantIdx, VariantDef>, + repr: ReprOptions, + ) -> Self { + debug!("AdtDef::new({:?}, {:?}, {:?}, {:?})", did, kind, variants, repr); + let mut flags = AdtFlags::NO_ADT_FLAGS; + + if kind == AdtKind::Enum && tcx.has_attr(did, sym::non_exhaustive) { + debug!("found non-exhaustive variant list for {:?}", did); + flags = flags | AdtFlags::IS_VARIANT_LIST_NON_EXHAUSTIVE; + } + + flags |= match kind { + AdtKind::Enum => AdtFlags::IS_ENUM, + AdtKind::Union => AdtFlags::IS_UNION, + AdtKind::Struct => AdtFlags::IS_STRUCT, + }; + + if kind == AdtKind::Struct && variants[VariantIdx::new(0)].ctor_def_id.is_some() { + flags |= AdtFlags::HAS_CTOR; + } + + let attrs = tcx.get_attrs(did); + if tcx.sess.contains_name(&attrs, sym::fundamental) { + flags |= AdtFlags::IS_FUNDAMENTAL; + } + if Some(did) == tcx.lang_items().phantom_data() { + flags |= AdtFlags::IS_PHANTOM_DATA; + } + if Some(did) == tcx.lang_items().owned_box() { + flags |= AdtFlags::IS_BOX; + } + if Some(did) == tcx.lang_items().manually_drop() { + flags |= AdtFlags::IS_MANUALLY_DROP; + } + + AdtDef { did, variants, flags, repr } + } + + /// Returns `true` if this is a struct. + #[inline] + pub fn is_struct(&self) -> bool { + self.flags.contains(AdtFlags::IS_STRUCT) + } + + /// Returns `true` if this is a union. + #[inline] + pub fn is_union(&self) -> bool { + self.flags.contains(AdtFlags::IS_UNION) + } + + /// Returns `true` if this is a enum. + #[inline] + pub fn is_enum(&self) -> bool { + self.flags.contains(AdtFlags::IS_ENUM) + } + + /// Returns `true` if the variant list of this ADT is `#[non_exhaustive]`. + #[inline] + pub fn is_variant_list_non_exhaustive(&self) -> bool { + self.flags.contains(AdtFlags::IS_VARIANT_LIST_NON_EXHAUSTIVE) + } + + /// Returns the kind of the ADT. + #[inline] + pub fn adt_kind(&self) -> AdtKind { + if self.is_enum() { + AdtKind::Enum + } else if self.is_union() { + AdtKind::Union + } else { + AdtKind::Struct + } + } + + /// Returns a description of this abstract data type. + pub fn descr(&self) -> &'static str { + match self.adt_kind() { + AdtKind::Struct => "struct", + AdtKind::Union => "union", + AdtKind::Enum => "enum", + } + } + + /// Returns a description of a variant of this abstract data type. + #[inline] + pub fn variant_descr(&self) -> &'static str { + match self.adt_kind() { + AdtKind::Struct => "struct", + AdtKind::Union => "union", + AdtKind::Enum => "variant", + } + } + + /// If this function returns `true`, it implies that `is_struct` must return `true`. + #[inline] + pub fn has_ctor(&self) -> bool { + self.flags.contains(AdtFlags::HAS_CTOR) + } + + /// Returns `true` if this type is `#[fundamental]` for the purposes + /// of coherence checking. + #[inline] + pub fn is_fundamental(&self) -> bool { + self.flags.contains(AdtFlags::IS_FUNDAMENTAL) + } + + /// Returns `true` if this is `PhantomData<T>`. + #[inline] + pub fn is_phantom_data(&self) -> bool { + self.flags.contains(AdtFlags::IS_PHANTOM_DATA) + } + + /// Returns `true` if this is Box<T>. + #[inline] + pub fn is_box(&self) -> bool { + self.flags.contains(AdtFlags::IS_BOX) + } + + /// Returns `true` if this is `ManuallyDrop<T>`. + #[inline] + pub fn is_manually_drop(&self) -> bool { + self.flags.contains(AdtFlags::IS_MANUALLY_DROP) + } + + /// Returns `true` if this type has a destructor. + pub fn has_dtor(&self, tcx: TyCtxt<'tcx>) -> bool { + self.destructor(tcx).is_some() + } + + /// Asserts this is a struct or union and returns its unique variant. + pub fn non_enum_variant(&self) -> &VariantDef { + assert!(self.is_struct() || self.is_union()); + &self.variants[VariantIdx::new(0)] + } + + #[inline] + pub fn predicates(&self, tcx: TyCtxt<'tcx>) -> GenericPredicates<'tcx> { + tcx.predicates_of(self.did) + } + + /// Returns an iterator over all fields contained + /// by this ADT. + #[inline] + pub fn all_fields(&self) -> impl Iterator<Item = &FieldDef> + Clone { + self.variants.iter().flat_map(|v| v.fields.iter()) + } + + /// Whether the ADT lacks fields. Note that this includes uninhabited enums, + /// e.g., `enum Void {}` is considered payload free as well. + pub fn is_payloadfree(&self) -> bool { + self.variants.iter().all(|v| v.fields.is_empty()) + } + + /// Return a `VariantDef` given a variant id. + pub fn variant_with_id(&self, vid: DefId) -> &VariantDef { + self.variants.iter().find(|v| v.def_id == vid).expect("variant_with_id: unknown variant") + } + + /// Return a `VariantDef` given a constructor id. + pub fn variant_with_ctor_id(&self, cid: DefId) -> &VariantDef { + self.variants + .iter() + .find(|v| v.ctor_def_id == Some(cid)) + .expect("variant_with_ctor_id: unknown variant") + } + + /// Return the index of `VariantDef` given a variant id. + pub fn variant_index_with_id(&self, vid: DefId) -> VariantIdx { + self.variants + .iter_enumerated() + .find(|(_, v)| v.def_id == vid) + .expect("variant_index_with_id: unknown variant") + .0 + } + + /// Return the index of `VariantDef` given a constructor id. + pub fn variant_index_with_ctor_id(&self, cid: DefId) -> VariantIdx { + self.variants + .iter_enumerated() + .find(|(_, v)| v.ctor_def_id == Some(cid)) + .expect("variant_index_with_ctor_id: unknown variant") + .0 + } + + pub fn variant_of_res(&self, res: Res) -> &VariantDef { + match res { + Res::Def(DefKind::Variant, vid) => self.variant_with_id(vid), + Res::Def(DefKind::Ctor(..), cid) => self.variant_with_ctor_id(cid), + Res::Def(DefKind::Struct, _) + | Res::Def(DefKind::Union, _) + | Res::Def(DefKind::TyAlias, _) + | Res::Def(DefKind::AssocTy, _) + | Res::SelfTy(..) + | Res::SelfCtor(..) => self.non_enum_variant(), + _ => bug!("unexpected res {:?} in variant_of_res", res), + } + } + + #[inline] + pub fn eval_explicit_discr(&self, tcx: TyCtxt<'tcx>, expr_did: DefId) -> Option<Discr<'tcx>> { + assert!(self.is_enum()); + let param_env = tcx.param_env(expr_did); + let repr_type = self.repr.discr_type(); + match tcx.const_eval_poly(expr_did) { + Ok(val) => { + let ty = repr_type.to_ty(tcx); + if let Some(b) = val.try_to_bits_for_ty(tcx, param_env, ty) { + trace!("discriminants: {} ({:?})", b, repr_type); + Some(Discr { val: b, ty }) + } else { + info!("invalid enum discriminant: {:#?}", val); + crate::mir::interpret::struct_error( + tcx.at(tcx.def_span(expr_did)), + "constant evaluation of enum discriminant resulted in non-integer", + ) + .emit(); + None + } + } + Err(err) => { + let msg = match err { + ErrorHandled::Reported(ErrorReported) | ErrorHandled::Linted => { + "enum discriminant evaluation failed" + } + ErrorHandled::TooGeneric => "enum discriminant depends on generics", + }; + tcx.sess.delay_span_bug(tcx.def_span(expr_did), msg); + None + } + } + } + + #[inline] + pub fn discriminants( + &'tcx self, + tcx: TyCtxt<'tcx>, + ) -> impl Iterator<Item = (VariantIdx, Discr<'tcx>)> + Captures<'tcx> { + assert!(self.is_enum()); + let repr_type = self.repr.discr_type(); + let initial = repr_type.initial_discriminant(tcx); + let mut prev_discr = None::<Discr<'tcx>>; + self.variants.iter_enumerated().map(move |(i, v)| { + let mut discr = prev_discr.map_or(initial, |d| d.wrap_incr(tcx)); + if let VariantDiscr::Explicit(expr_did) = v.discr { + if let Some(new_discr) = self.eval_explicit_discr(tcx, expr_did) { + discr = new_discr; + } + } + prev_discr = Some(discr); + + (i, discr) + }) + } + + #[inline] + pub fn variant_range(&self) -> Range<VariantIdx> { + VariantIdx::new(0)..VariantIdx::new(self.variants.len()) + } + + /// Computes the discriminant value used by a specific variant. + /// Unlike `discriminants`, this is (amortized) constant-time, + /// only doing at most one query for evaluating an explicit + /// discriminant (the last one before the requested variant), + /// assuming there are no constant-evaluation errors there. + #[inline] + pub fn discriminant_for_variant( + &self, + tcx: TyCtxt<'tcx>, + variant_index: VariantIdx, + ) -> Discr<'tcx> { + assert!(self.is_enum()); + let (val, offset) = self.discriminant_def_for_variant(variant_index); + let explicit_value = val + .and_then(|expr_did| self.eval_explicit_discr(tcx, expr_did)) + .unwrap_or_else(|| self.repr.discr_type().initial_discriminant(tcx)); + explicit_value.checked_add(tcx, offset as u128).0 + } + + /// Yields a `DefId` for the discriminant and an offset to add to it + /// Alternatively, if there is no explicit discriminant, returns the + /// inferred discriminant directly. + pub fn discriminant_def_for_variant(&self, variant_index: VariantIdx) -> (Option<DefId>, u32) { + assert!(!self.variants.is_empty()); + let mut explicit_index = variant_index.as_u32(); + let expr_did; + loop { + match self.variants[VariantIdx::from_u32(explicit_index)].discr { + ty::VariantDiscr::Relative(0) => { + expr_did = None; + break; + } + ty::VariantDiscr::Relative(distance) => { + explicit_index -= distance; + } + ty::VariantDiscr::Explicit(did) => { + expr_did = Some(did); + break; + } + } + } + (expr_did, variant_index.as_u32() - explicit_index) + } + + pub fn destructor(&self, tcx: TyCtxt<'tcx>) -> Option<Destructor> { + tcx.adt_destructor(self.did) + } + + /// Returns a list of types such that `Self: Sized` if and only + /// if that type is `Sized`, or `TyErr` if this type is recursive. + /// + /// Oddly enough, checking that the sized-constraint is `Sized` is + /// actually more expressive than checking all members: + /// the `Sized` trait is inductive, so an associated type that references + /// `Self` would prevent its containing ADT from being `Sized`. + /// + /// Due to normalization being eager, this applies even if + /// the associated type is behind a pointer (e.g., issue #31299). + pub fn sized_constraint(&self, tcx: TyCtxt<'tcx>) -> &'tcx [Ty<'tcx>] { + tcx.adt_sized_constraint(self.did).0 + } +} diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs index f380a9b4b81..785d96b5ada 100644 --- a/compiler/rustc_middle/src/ty/mod.rs +++ b/compiler/rustc_middle/src/ty/mod.rs @@ -14,6 +14,7 @@ pub use self::AssocItemContainer::*; pub use self::BorrowKind::*; pub use self::IntVarValue::*; pub use self::Variance::*; +pub use adt::*; pub use assoc::*; pub use generics::*; pub use upvar::*; @@ -24,39 +25,32 @@ use crate::hir::place::{ }; use crate::ich::StableHashingContext; use crate::middle::cstore::CrateStoreDyn; -use crate::mir::interpret::ErrorHandled; use crate::mir::{Body, GeneratorLayout}; use crate::traits::{self, Reveal}; use crate::ty; use crate::ty::subst::{GenericArg, InternalSubsts, Subst, SubstsRef}; -use crate::ty::util::{Discr, IntTypeExt}; +use crate::ty::util::Discr; use rustc_ast as ast; use rustc_attr as attr; use rustc_data_structures::captures::Captures; -use rustc_data_structures::fingerprint::Fingerprint; use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap}; use rustc_data_structures::stable_hasher::{HashStable, StableHasher}; use rustc_data_structures::sync::{self, par_iter, ParallelIterator}; use rustc_data_structures::tagged_ptr::CopyTaggedPtr; -use rustc_errors::ErrorReported; use rustc_hir as hir; use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res}; use rustc_hir::def_id::{CrateNum, DefId, DefIdMap, LocalDefId, CRATE_DEF_INDEX}; use rustc_hir::lang_items::LangItem; use rustc_hir::{Constness, Node}; -use rustc_index::vec::{Idx, IndexVec}; use rustc_macros::HashStable; -use rustc_serialize::{self, Encodable, Encoder}; -use rustc_session::DataTypeKind; use rustc_span::hygiene::ExpnId; -use rustc_span::symbol::{kw, sym, Ident, Symbol}; +use rustc_span::symbol::{kw, Ident, Symbol}; use rustc_span::Span; -use rustc_target::abi::{Align, VariantIdx}; +use rustc_target::abi::Align; -use std::cell::RefCell; use std::cmp::Ordering; use std::hash::{Hash, Hasher}; -use std::ops::{ControlFlow, Range}; +use std::ops::ControlFlow; use std::{fmt, ptr, str}; pub use crate::ty::diagnostics::*; @@ -107,6 +101,7 @@ pub mod trait_def; pub mod util; pub mod walk; +mod adt; mod assoc; mod consts; mod context; @@ -1449,32 +1444,6 @@ pub struct Destructor { bitflags! { #[derive(HashStable)] - pub struct AdtFlags: u32 { - const NO_ADT_FLAGS = 0; - /// Indicates whether the ADT is an enum. - const IS_ENUM = 1 << 0; - /// Indicates whether the ADT is a union. - const IS_UNION = 1 << 1; - /// Indicates whether the ADT is a struct. - const IS_STRUCT = 1 << 2; - /// Indicates whether the ADT is a struct and has a constructor. - const HAS_CTOR = 1 << 3; - /// Indicates whether the type is `PhantomData`. - const IS_PHANTOM_DATA = 1 << 4; - /// Indicates whether the type has a `#[fundamental]` attribute. - const IS_FUNDAMENTAL = 1 << 5; - /// Indicates whether the type is `Box`. - const IS_BOX = 1 << 6; - /// Indicates whether the type is `ManuallyDrop`. - const IS_MANUALLY_DROP = 1 << 7; - /// Indicates whether the variant list of this ADT is `#[non_exhaustive]`. - /// (i.e., this flag is never set unless this ADT is an enum). - const IS_VARIANT_LIST_NON_EXHAUSTIVE = 1 << 8; - } -} - -bitflags! { - #[derive(HashStable)] pub struct VariantFlags: u32 { const NO_VARIANT_FLAGS = 0; /// Indicates whether the field list of this variant is `#[non_exhaustive]`. @@ -1596,105 +1565,6 @@ pub struct FieldDef { pub vis: Visibility, } -/// The definition of a user-defined type, e.g., a `struct`, `enum`, or `union`. -/// -/// These are all interned (by `alloc_adt_def`) into the global arena. -/// -/// The initialism *ADT* stands for an [*algebraic data type (ADT)*][adt]. -/// This is slightly wrong because `union`s are not ADTs. -/// Moreover, Rust only allows recursive data types through indirection. -/// -/// [adt]: https://en.wikipedia.org/wiki/Algebraic_data_type -pub struct AdtDef { - /// The `DefId` of the struct, enum or union item. - pub did: DefId, - /// Variants of the ADT. If this is a struct or union, then there will be a single variant. - pub variants: IndexVec<VariantIdx, VariantDef>, - /// Flags of the ADT (e.g., is this a struct? is this non-exhaustive?). - flags: AdtFlags, - /// Repr options provided by the user. - pub repr: ReprOptions, -} - -impl PartialOrd for AdtDef { - fn partial_cmp(&self, other: &AdtDef) -> Option<Ordering> { - Some(self.cmp(&other)) - } -} - -/// There should be only one AdtDef for each `did`, therefore -/// it is fine to implement `Ord` only based on `did`. -impl Ord for AdtDef { - fn cmp(&self, other: &AdtDef) -> Ordering { - self.did.cmp(&other.did) - } -} - -impl PartialEq for AdtDef { - // `AdtDef`s are always interned, and this is part of `TyS` equality. - #[inline] - fn eq(&self, other: &Self) -> bool { - ptr::eq(self, other) - } -} - -impl Eq for AdtDef {} - -impl Hash for AdtDef { - #[inline] - fn hash<H: Hasher>(&self, s: &mut H) { - (self as *const AdtDef).hash(s) - } -} - -impl<S: Encoder> Encodable<S> for AdtDef { - fn encode(&self, s: &mut S) -> Result<(), S::Error> { - self.did.encode(s) - } -} - -impl<'a> HashStable<StableHashingContext<'a>> for AdtDef { - fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) { - thread_local! { - static CACHE: RefCell<FxHashMap<usize, Fingerprint>> = Default::default(); - } - - let hash: Fingerprint = CACHE.with(|cache| { - let addr = self as *const AdtDef as usize; - *cache.borrow_mut().entry(addr).or_insert_with(|| { - let ty::AdtDef { did, ref variants, ref flags, ref repr } = *self; - - let mut hasher = StableHasher::new(); - did.hash_stable(hcx, &mut hasher); - variants.hash_stable(hcx, &mut hasher); - flags.hash_stable(hcx, &mut hasher); - repr.hash_stable(hcx, &mut hasher); - - hasher.finish() - }) - }); - - hash.hash_stable(hcx, hasher); - } -} - -#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)] -pub enum AdtKind { - Struct, - Union, - Enum, -} - -impl Into<DataTypeKind> for AdtKind { - fn into(self) -> DataTypeKind { - match self { - AdtKind::Struct => DataTypeKind::Struct, - AdtKind::Union => DataTypeKind::Union, - AdtKind::Enum => DataTypeKind::Enum, - } - } -} - bitflags! { #[derive(TyEncodable, TyDecodable, Default, HashStable)] pub struct ReprFlags: u8 { @@ -1817,334 +1687,6 @@ impl ReprOptions { } } -impl<'tcx> AdtDef { - /// Creates a new `AdtDef`. - fn new( - tcx: TyCtxt<'_>, - did: DefId, - kind: AdtKind, - variants: IndexVec<VariantIdx, VariantDef>, - repr: ReprOptions, - ) -> Self { - debug!("AdtDef::new({:?}, {:?}, {:?}, {:?})", did, kind, variants, repr); - let mut flags = AdtFlags::NO_ADT_FLAGS; - - if kind == AdtKind::Enum && tcx.has_attr(did, sym::non_exhaustive) { - debug!("found non-exhaustive variant list for {:?}", did); - flags = flags | AdtFlags::IS_VARIANT_LIST_NON_EXHAUSTIVE; - } - - flags |= match kind { - AdtKind::Enum => AdtFlags::IS_ENUM, - AdtKind::Union => AdtFlags::IS_UNION, - AdtKind::Struct => AdtFlags::IS_STRUCT, - }; - - if kind == AdtKind::Struct && variants[VariantIdx::new(0)].ctor_def_id.is_some() { - flags |= AdtFlags::HAS_CTOR; - } - - let attrs = tcx.get_attrs(did); - if tcx.sess.contains_name(&attrs, sym::fundamental) { - flags |= AdtFlags::IS_FUNDAMENTAL; - } - if Some(did) == tcx.lang_items().phantom_data() { - flags |= AdtFlags::IS_PHANTOM_DATA; - } - if Some(did) == tcx.lang_items().owned_box() { - flags |= AdtFlags::IS_BOX; - } - if Some(did) == tcx.lang_items().manually_drop() { - flags |= AdtFlags::IS_MANUALLY_DROP; - } - - AdtDef { did, variants, flags, repr } - } - - /// Returns `true` if this is a struct. - #[inline] - pub fn is_struct(&self) -> bool { - self.flags.contains(AdtFlags::IS_STRUCT) - } - - /// Returns `true` if this is a union. - #[inline] - pub fn is_union(&self) -> bool { - self.flags.contains(AdtFlags::IS_UNION) - } - - /// Returns `true` if this is a enum. - #[inline] - pub fn is_enum(&self) -> bool { - self.flags.contains(AdtFlags::IS_ENUM) - } - - /// Returns `true` if the variant list of this ADT is `#[non_exhaustive]`. - #[inline] - pub fn is_variant_list_non_exhaustive(&self) -> bool { - self.flags.contains(AdtFlags::IS_VARIANT_LIST_NON_EXHAUSTIVE) - } - - /// Returns the kind of the ADT. - #[inline] - pub fn adt_kind(&self) -> AdtKind { - if self.is_enum() { - AdtKind::Enum - } else if self.is_union() { - AdtKind::Union - } else { - AdtKind::Struct - } - } - - /// Returns a description of this abstract data type. - pub fn descr(&self) -> &'static str { - match self.adt_kind() { - AdtKind::Struct => "struct", - AdtKind::Union => "union", - AdtKind::Enum => "enum", - } - } - - /// Returns a description of a variant of this abstract data type. - #[inline] - pub fn variant_descr(&self) -> &'static str { - match self.adt_kind() { - AdtKind::Struct => "struct", - AdtKind::Union => "union", - AdtKind::Enum => "variant", - } - } - - /// If this function returns `true`, it implies that `is_struct` must return `true`. - #[inline] - pub fn has_ctor(&self) -> bool { - self.flags.contains(AdtFlags::HAS_CTOR) - } - - /// Returns `true` if this type is `#[fundamental]` for the purposes - /// of coherence checking. - #[inline] - pub fn is_fundamental(&self) -> bool { - self.flags.contains(AdtFlags::IS_FUNDAMENTAL) - } - - /// Returns `true` if this is `PhantomData<T>`. - #[inline] - pub fn is_phantom_data(&self) -> bool { - self.flags.contains(AdtFlags::IS_PHANTOM_DATA) - } - - /// Returns `true` if this is Box<T>. - #[inline] - pub fn is_box(&self) -> bool { - self.flags.contains(AdtFlags::IS_BOX) - } - - /// Returns `true` if this is `ManuallyDrop<T>`. - #[inline] - pub fn is_manually_drop(&self) -> bool { - self.flags.contains(AdtFlags::IS_MANUALLY_DROP) - } - - /// Returns `true` if this type has a destructor. - pub fn has_dtor(&self, tcx: TyCtxt<'tcx>) -> bool { - self.destructor(tcx).is_some() - } - - /// Asserts this is a struct or union and returns its unique variant. - pub fn non_enum_variant(&self) -> &VariantDef { - assert!(self.is_struct() || self.is_union()); - &self.variants[VariantIdx::new(0)] - } - - #[inline] - pub fn predicates(&self, tcx: TyCtxt<'tcx>) -> GenericPredicates<'tcx> { - tcx.predicates_of(self.did) - } - - /// Returns an iterator over all fields contained - /// by this ADT. - #[inline] - pub fn all_fields(&self) -> impl Iterator<Item = &FieldDef> + Clone { - self.variants.iter().flat_map(|v| v.fields.iter()) - } - - /// Whether the ADT lacks fields. Note that this includes uninhabited enums, - /// e.g., `enum Void {}` is considered payload free as well. - pub fn is_payloadfree(&self) -> bool { - self.variants.iter().all(|v| v.fields.is_empty()) - } - - /// Return a `VariantDef` given a variant id. - pub fn variant_with_id(&self, vid: DefId) -> &VariantDef { - self.variants.iter().find(|v| v.def_id == vid).expect("variant_with_id: unknown variant") - } - - /// Return a `VariantDef` given a constructor id. - pub fn variant_with_ctor_id(&self, cid: DefId) -> &VariantDef { - self.variants - .iter() - .find(|v| v.ctor_def_id == Some(cid)) - .expect("variant_with_ctor_id: unknown variant") - } - - /// Return the index of `VariantDef` given a variant id. - pub fn variant_index_with_id(&self, vid: DefId) -> VariantIdx { - self.variants - .iter_enumerated() - .find(|(_, v)| v.def_id == vid) - .expect("variant_index_with_id: unknown variant") - .0 - } - - /// Return the index of `VariantDef` given a constructor id. - pub fn variant_index_with_ctor_id(&self, cid: DefId) -> VariantIdx { - self.variants - .iter_enumerated() - .find(|(_, v)| v.ctor_def_id == Some(cid)) - .expect("variant_index_with_ctor_id: unknown variant") - .0 - } - - pub fn variant_of_res(&self, res: Res) -> &VariantDef { - match res { - Res::Def(DefKind::Variant, vid) => self.variant_with_id(vid), - Res::Def(DefKind::Ctor(..), cid) => self.variant_with_ctor_id(cid), - Res::Def(DefKind::Struct, _) - | Res::Def(DefKind::Union, _) - | Res::Def(DefKind::TyAlias, _) - | Res::Def(DefKind::AssocTy, _) - | Res::SelfTy(..) - | Res::SelfCtor(..) => self.non_enum_variant(), - _ => bug!("unexpected res {:?} in variant_of_res", res), - } - } - - #[inline] - pub fn eval_explicit_discr(&self, tcx: TyCtxt<'tcx>, expr_did: DefId) -> Option<Discr<'tcx>> { - assert!(self.is_enum()); - let param_env = tcx.param_env(expr_did); - let repr_type = self.repr.discr_type(); - match tcx.const_eval_poly(expr_did) { - Ok(val) => { - let ty = repr_type.to_ty(tcx); - if let Some(b) = val.try_to_bits_for_ty(tcx, param_env, ty) { - trace!("discriminants: {} ({:?})", b, repr_type); - Some(Discr { val: b, ty }) - } else { - info!("invalid enum discriminant: {:#?}", val); - crate::mir::interpret::struct_error( - tcx.at(tcx.def_span(expr_did)), - "constant evaluation of enum discriminant resulted in non-integer", - ) - .emit(); - None - } - } - Err(err) => { - let msg = match err { - ErrorHandled::Reported(ErrorReported) | ErrorHandled::Linted => { - "enum discriminant evaluation failed" - } - ErrorHandled::TooGeneric => "enum discriminant depends on generics", - }; - tcx.sess.delay_span_bug(tcx.def_span(expr_did), msg); - None - } - } - } - - #[inline] - pub fn discriminants( - &'tcx self, - tcx: TyCtxt<'tcx>, - ) -> impl Iterator<Item = (VariantIdx, Discr<'tcx>)> + Captures<'tcx> { - assert!(self.is_enum()); - let repr_type = self.repr.discr_type(); - let initial = repr_type.initial_discriminant(tcx); - let mut prev_discr = None::<Discr<'tcx>>; - self.variants.iter_enumerated().map(move |(i, v)| { - let mut discr = prev_discr.map_or(initial, |d| d.wrap_incr(tcx)); - if let VariantDiscr::Explicit(expr_did) = v.discr { - if let Some(new_discr) = self.eval_explicit_discr(tcx, expr_did) { - discr = new_discr; - } - } - prev_discr = Some(discr); - - (i, discr) - }) - } - - #[inline] - pub fn variant_range(&self) -> Range<VariantIdx> { - VariantIdx::new(0)..VariantIdx::new(self.variants.len()) - } - - /// Computes the discriminant value used by a specific variant. - /// Unlike `discriminants`, this is (amortized) constant-time, - /// only doing at most one query for evaluating an explicit - /// discriminant (the last one before the requested variant), - /// assuming there are no constant-evaluation errors there. - #[inline] - pub fn discriminant_for_variant( - &self, - tcx: TyCtxt<'tcx>, - variant_index: VariantIdx, - ) -> Discr<'tcx> { - assert!(self.is_enum()); - let (val, offset) = self.discriminant_def_for_variant(variant_index); - let explicit_value = val - .and_then(|expr_did| self.eval_explicit_discr(tcx, expr_did)) - .unwrap_or_else(|| self.repr.discr_type().initial_discriminant(tcx)); - explicit_value.checked_add(tcx, offset as u128).0 - } - - /// Yields a `DefId` for the discriminant and an offset to add to it - /// Alternatively, if there is no explicit discriminant, returns the - /// inferred discriminant directly. - pub fn discriminant_def_for_variant(&self, variant_index: VariantIdx) -> (Option<DefId>, u32) { - assert!(!self.variants.is_empty()); - let mut explicit_index = variant_index.as_u32(); - let expr_did; - loop { - match self.variants[VariantIdx::from_u32(explicit_index)].discr { - ty::VariantDiscr::Relative(0) => { - expr_did = None; - break; - } - ty::VariantDiscr::Relative(distance) => { - explicit_index -= distance; - } - ty::VariantDiscr::Explicit(did) => { - expr_did = Some(did); - break; - } - } - } - (expr_did, variant_index.as_u32() - explicit_index) - } - - pub fn destructor(&self, tcx: TyCtxt<'tcx>) -> Option<Destructor> { - tcx.adt_destructor(self.did) - } - - /// Returns a list of types such that `Self: Sized` if and only - /// if that type is `Sized`, or `TyErr` if this type is recursive. - /// - /// Oddly enough, checking that the sized-constraint is `Sized` is - /// actually more expressive than checking all members: - /// the `Sized` trait is inductive, so an associated type that references - /// `Self` would prevent its containing ADT from being `Sized`. - /// - /// Due to normalization being eager, this applies even if - /// the associated type is behind a pointer (e.g., issue #31299). - pub fn sized_constraint(&self, tcx: TyCtxt<'tcx>) -> &'tcx [Ty<'tcx>] { - tcx.adt_sized_constraint(self.did).0 - } -} - impl<'tcx> FieldDef { /// Returns the type of this field. The `subst` is typically obtained /// via the second field of `TyKind::AdtDef`. @@ -2597,9 +2139,6 @@ impl<'tcx> TyCtxt<'tcx> { } } -#[derive(Clone, HashStable, Debug)] -pub struct AdtSizedConstraint<'tcx>(pub &'tcx [Ty<'tcx>]); - /// Yields the parent function's `DefId` if `def_id` is an `impl Trait` definition. pub fn is_impl_trait_defn(tcx: TyCtxt<'_>, def_id: DefId) -> Option<DefId> { if let Some(def_id) = def_id.as_local() { |