3171 lines
113 KiB
Rust
3171 lines
113 KiB
Rust
// Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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pub use self::Variance::*;
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pub use self::AssociatedItemContainer::*;
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pub use self::BorrowKind::*;
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pub use self::IntVarValue::*;
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pub use self::fold::TypeFoldable;
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use hir::{map as hir_map, FreevarMap, TraitMap};
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use hir::Node;
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use hir::def::{Def, CtorKind, ExportMap};
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use hir::def_id::{CrateNum, DefId, LocalDefId, CRATE_DEF_INDEX, LOCAL_CRATE};
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use hir::map::DefPathData;
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use rustc_data_structures::svh::Svh;
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use ich::Fingerprint;
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use ich::StableHashingContext;
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use infer::canonical::Canonical;
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use middle::lang_items::{FnTraitLangItem, FnMutTraitLangItem, FnOnceTraitLangItem};
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use middle::privacy::AccessLevels;
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use middle::resolve_lifetime::ObjectLifetimeDefault;
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use mir::Mir;
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use mir::interpret::{GlobalId, ErrorHandled};
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use mir::GeneratorLayout;
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use session::CrateDisambiguator;
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use traits::{self, Reveal};
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use ty;
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use ty::layout::VariantIdx;
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use ty::subst::{Subst, Substs};
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use ty::util::{IntTypeExt, Discr};
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use ty::walk::TypeWalker;
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use util::captures::Captures;
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use util::nodemap::{NodeSet, DefIdMap, FxHashMap};
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use arena::SyncDroplessArena;
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use session::DataTypeKind;
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use serialize::{self, Encodable, Encoder};
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use std::cell::RefCell;
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use std::cmp::{self, Ordering};
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use std::fmt;
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use std::hash::{Hash, Hasher};
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use std::ops::Deref;
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use rustc_data_structures::sync::{self, Lrc, ParallelIterator, par_iter};
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use std::slice;
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use std::vec::IntoIter;
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use std::{mem, ptr};
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use syntax::ast::{self, DUMMY_NODE_ID, Name, Ident, NodeId};
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use syntax::attr;
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use syntax::ext::hygiene::Mark;
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use syntax::symbol::{keywords, Symbol, LocalInternedString, InternedString};
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use syntax_pos::{DUMMY_SP, Span};
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use smallvec;
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use rustc_data_structures::indexed_vec::{Idx, IndexVec};
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use rustc_data_structures::stable_hasher::{StableHasher, StableHasherResult,
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HashStable};
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use hir;
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pub use self::sty::{Binder, BoundTy, BoundTyKind, BoundVar, DebruijnIndex, INNERMOST};
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pub use self::sty::{FnSig, GenSig, CanonicalPolyFnSig, PolyFnSig, PolyGenSig};
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pub use self::sty::{InferTy, ParamTy, ProjectionTy, ExistentialPredicate};
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pub use self::sty::{ClosureSubsts, GeneratorSubsts, UpvarSubsts, TypeAndMut};
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pub use self::sty::{TraitRef, TyKind, PolyTraitRef};
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pub use self::sty::{ExistentialTraitRef, PolyExistentialTraitRef};
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pub use self::sty::{ExistentialProjection, PolyExistentialProjection, Const};
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pub use self::sty::{BoundRegion, EarlyBoundRegion, FreeRegion, Region};
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pub use self::sty::RegionKind;
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pub use self::sty::{TyVid, IntVid, FloatVid, RegionVid};
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pub use self::sty::BoundRegion::*;
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pub use self::sty::InferTy::*;
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pub use self::sty::RegionKind::*;
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pub use self::sty::TyKind::*;
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pub use self::binding::BindingMode;
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pub use self::binding::BindingMode::*;
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pub use self::context::{TyCtxt, FreeRegionInfo, GlobalArenas, AllArenas, tls, keep_local};
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pub use self::context::{Lift, TypeckTables};
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pub use self::instance::{Instance, InstanceDef};
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pub use self::trait_def::TraitDef;
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pub use self::query::queries;
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pub mod adjustment;
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pub mod binding;
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pub mod cast;
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#[macro_use]
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pub mod codec;
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mod constness;
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pub mod error;
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mod erase_regions;
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pub mod fast_reject;
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pub mod fold;
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pub mod inhabitedness;
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pub mod item_path;
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pub mod layout;
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pub mod _match;
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pub mod outlives;
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pub mod query;
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pub mod relate;
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pub mod steal;
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pub mod subst;
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pub mod trait_def;
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pub mod walk;
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pub mod wf;
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pub mod util;
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mod context;
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mod flags;
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mod instance;
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mod structural_impls;
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mod sty;
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// Data types
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/// The complete set of all analyses described in this module. This is
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/// produced by the driver and fed to codegen and later passes.
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///
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/// NB: These contents are being migrated into queries using the
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/// *on-demand* infrastructure.
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#[derive(Clone)]
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pub struct CrateAnalysis {
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pub access_levels: Lrc<AccessLevels>,
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pub name: String,
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pub glob_map: Option<hir::GlobMap>,
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}
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#[derive(Clone)]
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pub struct Resolutions {
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pub freevars: FreevarMap,
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pub trait_map: TraitMap,
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pub maybe_unused_trait_imports: NodeSet,
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pub maybe_unused_extern_crates: Vec<(NodeId, Span)>,
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pub export_map: ExportMap,
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/// Extern prelude entries. The value is `true` if the entry was introduced
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/// via `extern crate` item and not `--extern` option or compiler built-in.
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pub extern_prelude: FxHashMap<Name, bool>,
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}
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#[derive(Clone, Copy, PartialEq, Eq, Debug)]
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pub enum AssociatedItemContainer {
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TraitContainer(DefId),
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ImplContainer(DefId),
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}
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impl AssociatedItemContainer {
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/// Asserts that this is the def-id of an associated item declared
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/// in a trait, and returns the trait def-id.
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pub fn assert_trait(&self) -> DefId {
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match *self {
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TraitContainer(id) => id,
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_ => bug!("associated item has wrong container type: {:?}", self)
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}
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}
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pub fn id(&self) -> DefId {
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match *self {
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TraitContainer(id) => id,
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ImplContainer(id) => id,
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}
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}
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}
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/// The "header" of an impl is everything outside the body: a Self type, a trait
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/// ref (in the case of a trait impl), and a set of predicates (from the
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/// bounds/where clauses).
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#[derive(Clone, PartialEq, Eq, Hash, Debug)]
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pub struct ImplHeader<'tcx> {
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pub impl_def_id: DefId,
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pub self_ty: Ty<'tcx>,
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pub trait_ref: Option<TraitRef<'tcx>>,
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pub predicates: Vec<Predicate<'tcx>>,
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}
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#[derive(Copy, Clone, Debug, PartialEq)]
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pub struct AssociatedItem {
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pub def_id: DefId,
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pub ident: Ident,
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pub kind: AssociatedKind,
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pub vis: Visibility,
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pub defaultness: hir::Defaultness,
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pub container: AssociatedItemContainer,
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/// Whether this is a method with an explicit self
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/// as its first argument, allowing method calls.
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pub method_has_self_argument: bool,
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}
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#[derive(Copy, Clone, PartialEq, Eq, Debug, Hash, RustcEncodable, RustcDecodable)]
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pub enum AssociatedKind {
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Const,
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Method,
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Existential,
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Type
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}
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impl AssociatedItem {
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pub fn def(&self) -> Def {
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match self.kind {
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AssociatedKind::Const => Def::AssociatedConst(self.def_id),
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AssociatedKind::Method => Def::Method(self.def_id),
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AssociatedKind::Type => Def::AssociatedTy(self.def_id),
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AssociatedKind::Existential => Def::AssociatedExistential(self.def_id),
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}
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}
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/// Tests whether the associated item admits a non-trivial implementation
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/// for !
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pub fn relevant_for_never<'tcx>(&self) -> bool {
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match self.kind {
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AssociatedKind::Existential |
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AssociatedKind::Const |
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AssociatedKind::Type => true,
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// FIXME(canndrew): Be more thorough here, check if any argument is uninhabited.
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AssociatedKind::Method => !self.method_has_self_argument,
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}
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}
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pub fn signature<'a, 'tcx>(&self, tcx: &TyCtxt<'a, 'tcx, 'tcx>) -> String {
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match self.kind {
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ty::AssociatedKind::Method => {
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// We skip the binder here because the binder would deanonymize all
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// late-bound regions, and we don't want method signatures to show up
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// `as for<'r> fn(&'r MyType)`. Pretty-printing handles late-bound
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// regions just fine, showing `fn(&MyType)`.
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tcx.fn_sig(self.def_id).skip_binder().to_string()
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}
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ty::AssociatedKind::Type => format!("type {};", self.ident),
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ty::AssociatedKind::Existential => format!("existential type {};", self.ident),
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ty::AssociatedKind::Const => {
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format!("const {}: {:?};", self.ident, tcx.type_of(self.def_id))
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}
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}
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}
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}
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#[derive(Clone, Debug, PartialEq, Eq, Copy, RustcEncodable, RustcDecodable)]
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pub enum Visibility {
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/// Visible everywhere (including in other crates).
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Public,
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/// Visible only in the given crate-local module.
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Restricted(DefId),
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/// Not visible anywhere in the local crate. This is the visibility of private external items.
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Invisible,
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}
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pub trait DefIdTree: Copy {
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fn parent(self, id: DefId) -> Option<DefId>;
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fn is_descendant_of(self, mut descendant: DefId, ancestor: DefId) -> bool {
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if descendant.krate != ancestor.krate {
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return false;
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}
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while descendant != ancestor {
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match self.parent(descendant) {
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Some(parent) => descendant = parent,
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None => return false,
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}
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}
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true
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}
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}
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impl<'a, 'gcx, 'tcx> DefIdTree for TyCtxt<'a, 'gcx, 'tcx> {
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fn parent(self, id: DefId) -> Option<DefId> {
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self.def_key(id).parent.map(|index| DefId { index: index, ..id })
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}
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}
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impl Visibility {
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pub fn from_hir(visibility: &hir::Visibility, id: NodeId, tcx: TyCtxt<'_, '_, '_>) -> Self {
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match visibility.node {
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hir::VisibilityKind::Public => Visibility::Public,
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hir::VisibilityKind::Crate(_) => Visibility::Restricted(DefId::local(CRATE_DEF_INDEX)),
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hir::VisibilityKind::Restricted { ref path, .. } => match path.def {
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// If there is no resolution, `resolve` will have already reported an error, so
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// assume that the visibility is public to avoid reporting more privacy errors.
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Def::Err => Visibility::Public,
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def => Visibility::Restricted(def.def_id()),
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},
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hir::VisibilityKind::Inherited => {
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Visibility::Restricted(tcx.hir.get_module_parent(id))
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}
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}
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}
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/// Returns `true` if an item with this visibility is accessible from the given block.
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pub fn is_accessible_from<T: DefIdTree>(self, module: DefId, tree: T) -> bool {
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let restriction = match self {
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// Public items are visible everywhere.
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Visibility::Public => return true,
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// Private items from other crates are visible nowhere.
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Visibility::Invisible => return false,
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// Restricted items are visible in an arbitrary local module.
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Visibility::Restricted(other) if other.krate != module.krate => return false,
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Visibility::Restricted(module) => module,
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};
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tree.is_descendant_of(module, restriction)
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}
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/// Returns `true` if this visibility is at least as accessible as the given visibility
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pub fn is_at_least<T: DefIdTree>(self, vis: Visibility, tree: T) -> bool {
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let vis_restriction = match vis {
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Visibility::Public => return self == Visibility::Public,
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Visibility::Invisible => return true,
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Visibility::Restricted(module) => module,
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};
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self.is_accessible_from(vis_restriction, tree)
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}
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// Returns `true` if this item is visible anywhere in the local crate.
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pub fn is_visible_locally(self) -> bool {
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match self {
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Visibility::Public => true,
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Visibility::Restricted(def_id) => def_id.is_local(),
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Visibility::Invisible => false,
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}
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}
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}
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#[derive(Copy, Clone, PartialEq, Eq, RustcDecodable, RustcEncodable, Hash)]
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pub enum Variance {
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Covariant, // T<A> <: T<B> iff A <: B -- e.g., function return type
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Invariant, // T<A> <: T<B> iff B == A -- e.g., type of mutable cell
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Contravariant, // T<A> <: T<B> iff B <: A -- e.g., function param type
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Bivariant, // T<A> <: T<B> -- e.g., unused type parameter
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}
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/// The crate variances map is computed during typeck and contains the
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/// variance of every item in the local crate. You should not use it
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/// directly, because to do so will make your pass dependent on the
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/// HIR of every item in the local crate. Instead, use
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/// `tcx.variances_of()` to get the variance for a *particular*
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/// item.
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pub struct CrateVariancesMap {
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/// For each item with generics, maps to a vector of the variance
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/// of its generics. If an item has no generics, it will have no
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/// entry.
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pub variances: FxHashMap<DefId, Lrc<Vec<ty::Variance>>>,
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/// An empty vector, useful for cloning.
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pub empty_variance: Lrc<Vec<ty::Variance>>,
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}
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impl Variance {
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/// `a.xform(b)` combines the variance of a context with the
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/// variance of a type with the following meaning. If we are in a
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/// context with variance `a`, and we encounter a type argument in
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/// a position with variance `b`, then `a.xform(b)` is the new
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/// variance with which the argument appears.
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///
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/// Example 1:
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///
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/// *mut Vec<i32>
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///
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/// Here, the "ambient" variance starts as covariant. `*mut T` is
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/// invariant with respect to `T`, so the variance in which the
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/// `Vec<i32>` appears is `Covariant.xform(Invariant)`, which
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/// yields `Invariant`. Now, the type `Vec<T>` is covariant with
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/// respect to its type argument `T`, and hence the variance of
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/// the `i32` here is `Invariant.xform(Covariant)`, which results
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/// (again) in `Invariant`.
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///
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/// Example 2:
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///
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/// fn(*const Vec<i32>, *mut Vec<i32)
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///
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/// The ambient variance is covariant. A `fn` type is
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/// contravariant with respect to its parameters, so the variance
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/// within which both pointer types appear is
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/// `Covariant.xform(Contravariant)`, or `Contravariant`. `*const
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/// T` is covariant with respect to `T`, so the variance within
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/// which the first `Vec<i32>` appears is
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/// `Contravariant.xform(Covariant)` or `Contravariant`. The same
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/// is true for its `i32` argument. In the `*mut T` case, the
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/// variance of `Vec<i32>` is `Contravariant.xform(Invariant)`,
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/// and hence the outermost type is `Invariant` with respect to
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/// `Vec<i32>` (and its `i32` argument).
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///
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/// Source: Figure 1 of "Taming the Wildcards:
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/// Combining Definition- and Use-Site Variance" published in PLDI'11.
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pub fn xform(self, v: ty::Variance) -> ty::Variance {
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match (self, v) {
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// Figure 1, column 1.
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(ty::Covariant, ty::Covariant) => ty::Covariant,
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(ty::Covariant, ty::Contravariant) => ty::Contravariant,
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(ty::Covariant, ty::Invariant) => ty::Invariant,
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(ty::Covariant, ty::Bivariant) => ty::Bivariant,
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// Figure 1, column 2.
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(ty::Contravariant, ty::Covariant) => ty::Contravariant,
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(ty::Contravariant, ty::Contravariant) => ty::Covariant,
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(ty::Contravariant, ty::Invariant) => ty::Invariant,
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(ty::Contravariant, ty::Bivariant) => ty::Bivariant,
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// Figure 1, column 3.
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(ty::Invariant, _) => ty::Invariant,
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// Figure 1, column 4.
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(ty::Bivariant, _) => ty::Bivariant,
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}
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}
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}
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// Contains information needed to resolve types and (in the future) look up
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// the types of AST nodes.
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#[derive(Copy, Clone, PartialEq, Eq, Hash)]
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pub struct CReaderCacheKey {
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pub cnum: CrateNum,
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pub pos: usize,
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}
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// Flags that we track on types. These flags are propagated upwards
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// through the type during type construction, so that we can quickly
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// check whether the type has various kinds of types in it without
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// recursing over the type itself.
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bitflags! {
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pub struct TypeFlags: u32 {
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const HAS_PARAMS = 1 << 0;
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const HAS_SELF = 1 << 1;
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const HAS_TY_INFER = 1 << 2;
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const HAS_RE_INFER = 1 << 3;
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const HAS_RE_SKOL = 1 << 4;
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/// Does this have any `ReEarlyBound` regions? Used to
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/// determine whether substitition is required, since those
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/// represent regions that are bound in a `ty::Generics` and
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/// hence may be substituted.
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const HAS_RE_EARLY_BOUND = 1 << 5;
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/// Does this have any region that "appears free" in the type?
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/// Basically anything but `ReLateBound` and `ReErased`.
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const HAS_FREE_REGIONS = 1 << 6;
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/// Is an error type reachable?
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const HAS_TY_ERR = 1 << 7;
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const HAS_PROJECTION = 1 << 8;
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// FIXME: Rename this to the actual property since it's used for generators too
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const HAS_TY_CLOSURE = 1 << 9;
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// `true` if there are "names" of types and regions and so forth
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// that are local to a particular fn
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const HAS_FREE_LOCAL_NAMES = 1 << 10;
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// Present if the type belongs in a local type context.
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// Only set for Infer other than Fresh.
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const KEEP_IN_LOCAL_TCX = 1 << 11;
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// Is there a projection that does not involve a bound region?
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// Currently we can't normalize projections w/ bound regions.
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const HAS_NORMALIZABLE_PROJECTION = 1 << 12;
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/// Does this have any `ReLateBound` regions? Used to check
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/// if a global bound is safe to evaluate.
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|
const HAS_RE_LATE_BOUND = 1 << 13;
|
|
|
|
const NEEDS_SUBST = TypeFlags::HAS_PARAMS.bits |
|
|
TypeFlags::HAS_SELF.bits |
|
|
TypeFlags::HAS_RE_EARLY_BOUND.bits;
|
|
|
|
// Flags representing the nominal content of a type,
|
|
// computed by FlagsComputation. If you add a new nominal
|
|
// flag, it should be added here too.
|
|
const NOMINAL_FLAGS = TypeFlags::HAS_PARAMS.bits |
|
|
TypeFlags::HAS_SELF.bits |
|
|
TypeFlags::HAS_TY_INFER.bits |
|
|
TypeFlags::HAS_RE_INFER.bits |
|
|
TypeFlags::HAS_RE_SKOL.bits |
|
|
TypeFlags::HAS_RE_EARLY_BOUND.bits |
|
|
TypeFlags::HAS_FREE_REGIONS.bits |
|
|
TypeFlags::HAS_TY_ERR.bits |
|
|
TypeFlags::HAS_PROJECTION.bits |
|
|
TypeFlags::HAS_TY_CLOSURE.bits |
|
|
TypeFlags::HAS_FREE_LOCAL_NAMES.bits |
|
|
TypeFlags::KEEP_IN_LOCAL_TCX.bits |
|
|
TypeFlags::HAS_RE_LATE_BOUND.bits;
|
|
}
|
|
}
|
|
|
|
pub struct TyS<'tcx> {
|
|
pub sty: TyKind<'tcx>,
|
|
pub flags: TypeFlags,
|
|
|
|
/// This is a kind of confusing thing: it stores the smallest
|
|
/// binder such that
|
|
///
|
|
/// (a) the binder itself captures nothing but
|
|
/// (b) all the late-bound things within the type are captured
|
|
/// by some sub-binder.
|
|
///
|
|
/// So, for a type without any late-bound things, like `u32`, this
|
|
/// will be INNERMOST, because that is the innermost binder that
|
|
/// captures nothing. But for a type `&'D u32`, where `'D` is a
|
|
/// late-bound region with debruijn index D, this would be D+1 --
|
|
/// the binder itself does not capture D, but D is captured by an
|
|
/// inner binder.
|
|
///
|
|
/// We call this concept an "exclusive" binder D (because all
|
|
/// debruijn indices within the type are contained within `0..D`
|
|
/// (exclusive)).
|
|
outer_exclusive_binder: ty::DebruijnIndex,
|
|
}
|
|
|
|
impl<'tcx> Ord for TyS<'tcx> {
|
|
fn cmp(&self, other: &TyS<'tcx>) -> Ordering {
|
|
self.sty.cmp(&other.sty)
|
|
}
|
|
}
|
|
|
|
impl<'tcx> PartialOrd for TyS<'tcx> {
|
|
fn partial_cmp(&self, other: &TyS<'tcx>) -> Option<Ordering> {
|
|
Some(self.sty.cmp(&other.sty))
|
|
}
|
|
}
|
|
|
|
impl<'tcx> PartialEq for TyS<'tcx> {
|
|
#[inline]
|
|
fn eq(&self, other: &TyS<'tcx>) -> bool {
|
|
ptr::eq(self, other)
|
|
}
|
|
}
|
|
impl<'tcx> Eq for TyS<'tcx> {}
|
|
|
|
impl<'tcx> Hash for TyS<'tcx> {
|
|
fn hash<H: Hasher>(&self, s: &mut H) {
|
|
(self as *const TyS<'_>).hash(s)
|
|
}
|
|
}
|
|
|
|
impl<'tcx> TyS<'tcx> {
|
|
pub fn is_primitive_ty(&self) -> bool {
|
|
match self.sty {
|
|
TyKind::Bool |
|
|
TyKind::Char |
|
|
TyKind::Int(_) |
|
|
TyKind::Uint(_) |
|
|
TyKind::Float(_) |
|
|
TyKind::Infer(InferTy::IntVar(_)) |
|
|
TyKind::Infer(InferTy::FloatVar(_)) |
|
|
TyKind::Infer(InferTy::FreshIntTy(_)) |
|
|
TyKind::Infer(InferTy::FreshFloatTy(_)) => true,
|
|
TyKind::Ref(_, x, _) => x.is_primitive_ty(),
|
|
_ => false,
|
|
}
|
|
}
|
|
|
|
pub fn is_suggestable(&self) -> bool {
|
|
match self.sty {
|
|
TyKind::Opaque(..) |
|
|
TyKind::FnDef(..) |
|
|
TyKind::FnPtr(..) |
|
|
TyKind::Dynamic(..) |
|
|
TyKind::Closure(..) |
|
|
TyKind::Infer(..) |
|
|
TyKind::Projection(..) => false,
|
|
_ => true,
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'a, 'gcx> HashStable<StableHashingContext<'a>> for ty::TyS<'gcx> {
|
|
fn hash_stable<W: StableHasherResult>(&self,
|
|
hcx: &mut StableHashingContext<'a>,
|
|
hasher: &mut StableHasher<W>) {
|
|
let ty::TyS {
|
|
ref sty,
|
|
|
|
// The other fields just provide fast access to information that is
|
|
// also contained in `sty`, so no need to hash them.
|
|
flags: _,
|
|
|
|
outer_exclusive_binder: _,
|
|
} = *self;
|
|
|
|
sty.hash_stable(hcx, hasher);
|
|
}
|
|
}
|
|
|
|
pub type Ty<'tcx> = &'tcx TyS<'tcx>;
|
|
|
|
impl<'tcx> serialize::UseSpecializedEncodable for Ty<'tcx> {}
|
|
impl<'tcx> serialize::UseSpecializedDecodable for Ty<'tcx> {}
|
|
|
|
pub type CanonicalTy<'gcx> = Canonical<'gcx, Ty<'gcx>>;
|
|
|
|
extern {
|
|
/// A dummy type used to force List to by unsized without requiring fat pointers
|
|
type OpaqueListContents;
|
|
}
|
|
|
|
/// A wrapper for slices with the additional invariant
|
|
/// that the slice is interned and no other slice with
|
|
/// the same contents can exist in the same context.
|
|
/// This means we can use pointer for both
|
|
/// equality comparisons and hashing.
|
|
/// Note: `Slice` was already taken by the `Ty`.
|
|
#[repr(C)]
|
|
pub struct List<T> {
|
|
len: usize,
|
|
data: [T; 0],
|
|
opaque: OpaqueListContents,
|
|
}
|
|
|
|
unsafe impl<T: Sync> Sync for List<T> {}
|
|
|
|
impl<T: Copy> List<T> {
|
|
#[inline]
|
|
fn from_arena<'tcx>(arena: &'tcx SyncDroplessArena, slice: &[T]) -> &'tcx List<T> {
|
|
assert!(!mem::needs_drop::<T>());
|
|
assert!(mem::size_of::<T>() != 0);
|
|
assert!(slice.len() != 0);
|
|
|
|
// Align up the size of the len (usize) field
|
|
let align = mem::align_of::<T>();
|
|
let align_mask = align - 1;
|
|
let offset = mem::size_of::<usize>();
|
|
let offset = (offset + align_mask) & !align_mask;
|
|
|
|
let size = offset + slice.len() * mem::size_of::<T>();
|
|
|
|
let mem = arena.alloc_raw(
|
|
size,
|
|
cmp::max(mem::align_of::<T>(), mem::align_of::<usize>()));
|
|
unsafe {
|
|
let result = &mut *(mem.as_mut_ptr() as *mut List<T>);
|
|
// Write the length
|
|
result.len = slice.len();
|
|
|
|
// Write the elements
|
|
let arena_slice = slice::from_raw_parts_mut(result.data.as_mut_ptr(), result.len);
|
|
arena_slice.copy_from_slice(slice);
|
|
|
|
result
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<T: fmt::Debug> fmt::Debug for List<T> {
|
|
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
|
(**self).fmt(f)
|
|
}
|
|
}
|
|
|
|
impl<T: Encodable> Encodable for List<T> {
|
|
#[inline]
|
|
fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
|
|
(**self).encode(s)
|
|
}
|
|
}
|
|
|
|
impl<T> Ord for List<T> where T: Ord {
|
|
fn cmp(&self, other: &List<T>) -> Ordering {
|
|
if self == other { Ordering::Equal } else {
|
|
<[T] as Ord>::cmp(&**self, &**other)
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<T> PartialOrd for List<T> where T: PartialOrd {
|
|
fn partial_cmp(&self, other: &List<T>) -> Option<Ordering> {
|
|
if self == other { Some(Ordering::Equal) } else {
|
|
<[T] as PartialOrd>::partial_cmp(&**self, &**other)
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<T: PartialEq> PartialEq for List<T> {
|
|
#[inline]
|
|
fn eq(&self, other: &List<T>) -> bool {
|
|
ptr::eq(self, other)
|
|
}
|
|
}
|
|
impl<T: Eq> Eq for List<T> {}
|
|
|
|
impl<T> Hash for List<T> {
|
|
#[inline]
|
|
fn hash<H: Hasher>(&self, s: &mut H) {
|
|
(self as *const List<T>).hash(s)
|
|
}
|
|
}
|
|
|
|
impl<T> Deref for List<T> {
|
|
type Target = [T];
|
|
#[inline(always)]
|
|
fn deref(&self) -> &[T] {
|
|
unsafe {
|
|
slice::from_raw_parts(self.data.as_ptr(), self.len)
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'a, T> IntoIterator for &'a List<T> {
|
|
type Item = &'a T;
|
|
type IntoIter = <&'a [T] as IntoIterator>::IntoIter;
|
|
#[inline(always)]
|
|
fn into_iter(self) -> Self::IntoIter {
|
|
self[..].iter()
|
|
}
|
|
}
|
|
|
|
impl<'tcx> serialize::UseSpecializedDecodable for &'tcx List<Ty<'tcx>> {}
|
|
|
|
impl<T> List<T> {
|
|
#[inline(always)]
|
|
pub fn empty<'a>() -> &'a List<T> {
|
|
#[repr(align(64), C)]
|
|
struct EmptySlice([u8; 64]);
|
|
static EMPTY_SLICE: EmptySlice = EmptySlice([0; 64]);
|
|
assert!(mem::align_of::<T>() <= 64);
|
|
unsafe {
|
|
&*(&EMPTY_SLICE as *const _ as *const List<T>)
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Upvars do not get their own node-id. Instead, we use the pair of
|
|
/// the original var id (that is, the root variable that is referenced
|
|
/// by the upvar) and the id of the closure expression.
|
|
#[derive(Clone, Copy, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
|
|
pub struct UpvarId {
|
|
pub var_id: hir::HirId,
|
|
pub closure_expr_id: LocalDefId,
|
|
}
|
|
|
|
#[derive(Clone, PartialEq, Eq, Hash, Debug, RustcEncodable, RustcDecodable, Copy)]
|
|
pub enum BorrowKind {
|
|
/// Data must be immutable and is aliasable.
|
|
ImmBorrow,
|
|
|
|
/// Data must be immutable but not aliasable. This kind of borrow
|
|
/// cannot currently be expressed by the user and is used only in
|
|
/// implicit closure bindings. It is needed when the closure
|
|
/// is borrowing or mutating a mutable referent, e.g.:
|
|
///
|
|
/// let x: &mut isize = ...;
|
|
/// let y = || *x += 5;
|
|
///
|
|
/// If we were to try to translate this closure into a more explicit
|
|
/// form, we'd encounter an error with the code as written:
|
|
///
|
|
/// struct Env { x: & &mut isize }
|
|
/// let x: &mut isize = ...;
|
|
/// let y = (&mut Env { &x }, fn_ptr); // Closure is pair of env and fn
|
|
/// fn fn_ptr(env: &mut Env) { **env.x += 5; }
|
|
///
|
|
/// This is then illegal because you cannot mutate a `&mut` found
|
|
/// in an aliasable location. To solve, you'd have to translate with
|
|
/// an `&mut` borrow:
|
|
///
|
|
/// struct Env { x: & &mut isize }
|
|
/// let x: &mut isize = ...;
|
|
/// let y = (&mut Env { &mut x }, fn_ptr); // changed from &x to &mut x
|
|
/// fn fn_ptr(env: &mut Env) { **env.x += 5; }
|
|
///
|
|
/// Now the assignment to `**env.x` is legal, but creating a
|
|
/// mutable pointer to `x` is not because `x` is not mutable. We
|
|
/// could fix this by declaring `x` as `let mut x`. This is ok in
|
|
/// user code, if awkward, but extra weird for closures, since the
|
|
/// borrow is hidden.
|
|
///
|
|
/// So we introduce a "unique imm" borrow -- the referent is
|
|
/// immutable, but not aliasable. This solves the problem. For
|
|
/// simplicity, we don't give users the way to express this
|
|
/// borrow, it's just used when translating closures.
|
|
UniqueImmBorrow,
|
|
|
|
/// Data is mutable and not aliasable.
|
|
MutBorrow
|
|
}
|
|
|
|
/// Information describing the capture of an upvar. This is computed
|
|
/// during `typeck`, specifically by `regionck`.
|
|
#[derive(PartialEq, Clone, Debug, Copy, RustcEncodable, RustcDecodable)]
|
|
pub enum UpvarCapture<'tcx> {
|
|
/// Upvar is captured by value. This is always true when the
|
|
/// closure is labeled `move`, but can also be true in other cases
|
|
/// depending on inference.
|
|
ByValue,
|
|
|
|
/// Upvar is captured by reference.
|
|
ByRef(UpvarBorrow<'tcx>),
|
|
}
|
|
|
|
#[derive(PartialEq, Clone, Copy, RustcEncodable, RustcDecodable)]
|
|
pub struct UpvarBorrow<'tcx> {
|
|
/// The kind of borrow: by-ref upvars have access to shared
|
|
/// immutable borrows, which are not part of the normal language
|
|
/// syntax.
|
|
pub kind: BorrowKind,
|
|
|
|
/// Region of the resulting reference.
|
|
pub region: ty::Region<'tcx>,
|
|
}
|
|
|
|
pub type UpvarCaptureMap<'tcx> = FxHashMap<UpvarId, UpvarCapture<'tcx>>;
|
|
|
|
#[derive(Copy, Clone)]
|
|
pub struct ClosureUpvar<'tcx> {
|
|
pub def: Def,
|
|
pub span: Span,
|
|
pub ty: Ty<'tcx>,
|
|
}
|
|
|
|
#[derive(Clone, Copy, PartialEq, Eq)]
|
|
pub enum IntVarValue {
|
|
IntType(ast::IntTy),
|
|
UintType(ast::UintTy),
|
|
}
|
|
|
|
#[derive(Clone, Copy, PartialEq, Eq)]
|
|
pub struct FloatVarValue(pub ast::FloatTy);
|
|
|
|
impl ty::EarlyBoundRegion {
|
|
pub fn to_bound_region(&self) -> ty::BoundRegion {
|
|
ty::BoundRegion::BrNamed(self.def_id, self.name)
|
|
}
|
|
|
|
/// Does this early bound region have a name? Early bound regions normally
|
|
/// always have names except when using anonymous lifetimes (`'_`).
|
|
pub fn has_name(&self) -> bool {
|
|
self.name != keywords::UnderscoreLifetime.name().as_interned_str()
|
|
}
|
|
}
|
|
|
|
#[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
|
|
pub enum GenericParamDefKind {
|
|
Lifetime,
|
|
Type {
|
|
has_default: bool,
|
|
object_lifetime_default: ObjectLifetimeDefault,
|
|
synthetic: Option<hir::SyntheticTyParamKind>,
|
|
}
|
|
}
|
|
|
|
#[derive(Clone, RustcEncodable, RustcDecodable)]
|
|
pub struct GenericParamDef {
|
|
pub name: InternedString,
|
|
pub def_id: DefId,
|
|
pub index: u32,
|
|
|
|
/// `pure_wrt_drop`, set by the (unsafe) `#[may_dangle]` attribute
|
|
/// on generic parameter `'a`/`T`, asserts data behind the parameter
|
|
/// `'a`/`T` won't be accessed during the parent type's `Drop` impl.
|
|
pub pure_wrt_drop: bool,
|
|
|
|
pub kind: GenericParamDefKind,
|
|
}
|
|
|
|
impl GenericParamDef {
|
|
pub fn to_early_bound_region_data(&self) -> ty::EarlyBoundRegion {
|
|
if let GenericParamDefKind::Lifetime = self.kind {
|
|
ty::EarlyBoundRegion {
|
|
def_id: self.def_id,
|
|
index: self.index,
|
|
name: self.name,
|
|
}
|
|
} else {
|
|
bug!("cannot convert a non-lifetime parameter def to an early bound region")
|
|
}
|
|
}
|
|
|
|
pub fn to_bound_region(&self) -> ty::BoundRegion {
|
|
if let GenericParamDefKind::Lifetime = self.kind {
|
|
self.to_early_bound_region_data().to_bound_region()
|
|
} else {
|
|
bug!("cannot convert a non-lifetime parameter def to an early bound region")
|
|
}
|
|
}
|
|
}
|
|
|
|
#[derive(Default)]
|
|
pub struct GenericParamCount {
|
|
pub lifetimes: usize,
|
|
pub types: usize,
|
|
}
|
|
|
|
/// Information about the formal type/lifetime parameters associated
|
|
/// with an item or method. Analogous to hir::Generics.
|
|
///
|
|
/// The ordering of parameters is the same as in Subst (excluding child generics):
|
|
/// Self (optionally), Lifetime params..., Type params...
|
|
#[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
|
|
pub struct Generics {
|
|
pub parent: Option<DefId>,
|
|
pub parent_count: usize,
|
|
pub params: Vec<GenericParamDef>,
|
|
|
|
/// Reverse map to the `index` field of each `GenericParamDef`
|
|
pub param_def_id_to_index: FxHashMap<DefId, u32>,
|
|
|
|
pub has_self: bool,
|
|
pub has_late_bound_regions: Option<Span>,
|
|
}
|
|
|
|
impl<'a, 'gcx, 'tcx> Generics {
|
|
pub fn count(&self) -> usize {
|
|
self.parent_count + self.params.len()
|
|
}
|
|
|
|
pub fn own_counts(&self) -> GenericParamCount {
|
|
// We could cache this as a property of `GenericParamCount`, but
|
|
// the aim is to refactor this away entirely eventually and the
|
|
// presence of this method will be a constant reminder.
|
|
let mut own_counts: GenericParamCount = Default::default();
|
|
|
|
for param in &self.params {
|
|
match param.kind {
|
|
GenericParamDefKind::Lifetime => own_counts.lifetimes += 1,
|
|
GenericParamDefKind::Type { .. } => own_counts.types += 1,
|
|
};
|
|
}
|
|
|
|
own_counts
|
|
}
|
|
|
|
pub fn requires_monomorphization(&self, tcx: TyCtxt<'a, 'gcx, 'tcx>) -> bool {
|
|
for param in &self.params {
|
|
match param.kind {
|
|
GenericParamDefKind::Type { .. } => return true,
|
|
GenericParamDefKind::Lifetime => {}
|
|
}
|
|
}
|
|
if let Some(parent_def_id) = self.parent {
|
|
let parent = tcx.generics_of(parent_def_id);
|
|
parent.requires_monomorphization(tcx)
|
|
} else {
|
|
false
|
|
}
|
|
}
|
|
|
|
pub fn region_param(&'tcx self,
|
|
param: &EarlyBoundRegion,
|
|
tcx: TyCtxt<'a, 'gcx, 'tcx>)
|
|
-> &'tcx GenericParamDef
|
|
{
|
|
if let Some(index) = param.index.checked_sub(self.parent_count as u32) {
|
|
let param = &self.params[index as usize];
|
|
match param.kind {
|
|
ty::GenericParamDefKind::Lifetime => param,
|
|
_ => bug!("expected lifetime parameter, but found another generic parameter")
|
|
}
|
|
} else {
|
|
tcx.generics_of(self.parent.expect("parent_count > 0 but no parent?"))
|
|
.region_param(param, tcx)
|
|
}
|
|
}
|
|
|
|
/// Returns the `GenericParamDef` associated with this `ParamTy`.
|
|
pub fn type_param(&'tcx self,
|
|
param: &ParamTy,
|
|
tcx: TyCtxt<'a, 'gcx, 'tcx>)
|
|
-> &'tcx GenericParamDef {
|
|
if let Some(index) = param.idx.checked_sub(self.parent_count as u32) {
|
|
let param = &self.params[index as usize];
|
|
match param.kind {
|
|
ty::GenericParamDefKind::Type {..} => param,
|
|
_ => bug!("expected type parameter, but found another generic parameter")
|
|
}
|
|
} else {
|
|
tcx.generics_of(self.parent.expect("parent_count > 0 but no parent?"))
|
|
.type_param(param, tcx)
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Bounds on generics.
|
|
#[derive(Clone, Default)]
|
|
pub struct GenericPredicates<'tcx> {
|
|
pub parent: Option<DefId>,
|
|
pub predicates: Vec<(Predicate<'tcx>, Span)>,
|
|
}
|
|
|
|
impl<'tcx> serialize::UseSpecializedEncodable for GenericPredicates<'tcx> {}
|
|
impl<'tcx> serialize::UseSpecializedDecodable for GenericPredicates<'tcx> {}
|
|
|
|
impl<'a, 'gcx, 'tcx> GenericPredicates<'tcx> {
|
|
pub fn instantiate(&self, tcx: TyCtxt<'a, 'gcx, 'tcx>, substs: &Substs<'tcx>)
|
|
-> InstantiatedPredicates<'tcx> {
|
|
let mut instantiated = InstantiatedPredicates::empty();
|
|
self.instantiate_into(tcx, &mut instantiated, substs);
|
|
instantiated
|
|
}
|
|
|
|
pub fn instantiate_own(&self, tcx: TyCtxt<'a, 'gcx, 'tcx>, substs: &Substs<'tcx>)
|
|
-> InstantiatedPredicates<'tcx> {
|
|
InstantiatedPredicates {
|
|
predicates: self.predicates.iter().map(|(p, _)| p.subst(tcx, substs)).collect(),
|
|
}
|
|
}
|
|
|
|
fn instantiate_into(&self, tcx: TyCtxt<'a, 'gcx, 'tcx>,
|
|
instantiated: &mut InstantiatedPredicates<'tcx>,
|
|
substs: &Substs<'tcx>) {
|
|
if let Some(def_id) = self.parent {
|
|
tcx.predicates_of(def_id).instantiate_into(tcx, instantiated, substs);
|
|
}
|
|
instantiated.predicates.extend(
|
|
self.predicates.iter().map(|(p, _)| p.subst(tcx, substs)),
|
|
);
|
|
}
|
|
|
|
pub fn instantiate_identity(&self, tcx: TyCtxt<'a, 'gcx, 'tcx>)
|
|
-> InstantiatedPredicates<'tcx> {
|
|
let mut instantiated = InstantiatedPredicates::empty();
|
|
self.instantiate_identity_into(tcx, &mut instantiated);
|
|
instantiated
|
|
}
|
|
|
|
fn instantiate_identity_into(&self, tcx: TyCtxt<'a, 'gcx, 'tcx>,
|
|
instantiated: &mut InstantiatedPredicates<'tcx>) {
|
|
if let Some(def_id) = self.parent {
|
|
tcx.predicates_of(def_id).instantiate_identity_into(tcx, instantiated);
|
|
}
|
|
instantiated.predicates.extend(self.predicates.iter().map(|&(p, _)| p))
|
|
}
|
|
|
|
pub fn instantiate_supertrait(&self, tcx: TyCtxt<'a, 'gcx, 'tcx>,
|
|
poly_trait_ref: &ty::PolyTraitRef<'tcx>)
|
|
-> InstantiatedPredicates<'tcx>
|
|
{
|
|
assert_eq!(self.parent, None);
|
|
InstantiatedPredicates {
|
|
predicates: self.predicates.iter().map(|(pred, _)| {
|
|
pred.subst_supertrait(tcx, poly_trait_ref)
|
|
}).collect()
|
|
}
|
|
}
|
|
}
|
|
|
|
#[derive(Clone, Copy, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
|
|
pub enum Predicate<'tcx> {
|
|
/// Corresponds to `where Foo: Bar<A,B,C>`. `Foo` here would be
|
|
/// the `Self` type of the trait reference and `A`, `B`, and `C`
|
|
/// would be the type parameters.
|
|
Trait(PolyTraitPredicate<'tcx>),
|
|
|
|
/// where `'a: 'b`
|
|
RegionOutlives(PolyRegionOutlivesPredicate<'tcx>),
|
|
|
|
/// where `T: 'a`
|
|
TypeOutlives(PolyTypeOutlivesPredicate<'tcx>),
|
|
|
|
/// where `<T as TraitRef>::Name == X`, approximately.
|
|
/// See the `ProjectionPredicate` struct for details.
|
|
Projection(PolyProjectionPredicate<'tcx>),
|
|
|
|
/// no syntax: `T` well-formed
|
|
WellFormed(Ty<'tcx>),
|
|
|
|
/// trait must be object-safe
|
|
ObjectSafe(DefId),
|
|
|
|
/// No direct syntax. May be thought of as `where T: FnFoo<...>`
|
|
/// for some substitutions `...` and `T` being a closure type.
|
|
/// Satisfied (or refuted) once we know the closure's kind.
|
|
ClosureKind(DefId, ClosureSubsts<'tcx>, ClosureKind),
|
|
|
|
/// `T1 <: T2`
|
|
Subtype(PolySubtypePredicate<'tcx>),
|
|
|
|
/// Constant initializer must evaluate successfully.
|
|
ConstEvaluatable(DefId, &'tcx Substs<'tcx>),
|
|
}
|
|
|
|
/// 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.
|
|
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: FxHashMap<DefId, Lrc<Vec<ty::Predicate<'tcx>>>>,
|
|
|
|
/// An empty vector, useful for cloning.
|
|
pub empty_predicate: Lrc<Vec<ty::Predicate<'tcx>>>,
|
|
}
|
|
|
|
impl<'tcx> AsRef<Predicate<'tcx>> for Predicate<'tcx> {
|
|
fn as_ref(&self) -> &Predicate<'tcx> {
|
|
self
|
|
}
|
|
}
|
|
|
|
impl<'a, 'gcx, 'tcx> Predicate<'tcx> {
|
|
/// Performs a substitution suitable for going from a
|
|
/// poly-trait-ref to supertraits that must hold if that
|
|
/// poly-trait-ref holds. This is slightly different from a normal
|
|
/// substitution in terms of what happens with bound regions. See
|
|
/// lengthy comment below for details.
|
|
pub fn subst_supertrait(&self, tcx: TyCtxt<'a, 'gcx, 'tcx>,
|
|
trait_ref: &ty::PolyTraitRef<'tcx>)
|
|
-> ty::Predicate<'tcx>
|
|
{
|
|
// The interaction between HRTB and supertraits is not entirely
|
|
// obvious. Let me walk you (and myself) through an example.
|
|
//
|
|
// Let's start with an easy case. Consider two traits:
|
|
//
|
|
// trait Foo<'a>: Bar<'a,'a> { }
|
|
// trait Bar<'b,'c> { }
|
|
//
|
|
// Now, if we have a trait reference `for<'x> T: Foo<'x>`, then
|
|
// we can deduce that `for<'x> T: Bar<'x,'x>`. Basically, if we
|
|
// knew that `Foo<'x>` (for any 'x) then we also know that
|
|
// `Bar<'x,'x>` (for any 'x). This more-or-less falls out from
|
|
// normal substitution.
|
|
//
|
|
// In terms of why this is sound, the idea is that whenever there
|
|
// is an impl of `T:Foo<'a>`, it must show that `T:Bar<'a,'a>`
|
|
// holds. So if there is an impl of `T:Foo<'a>` that applies to
|
|
// all `'a`, then we must know that `T:Bar<'a,'a>` holds for all
|
|
// `'a`.
|
|
//
|
|
// Another example to be careful of is this:
|
|
//
|
|
// trait Foo1<'a>: for<'b> Bar1<'a,'b> { }
|
|
// trait Bar1<'b,'c> { }
|
|
//
|
|
// Here, if we have `for<'x> T: Foo1<'x>`, then what do we know?
|
|
// The answer is that we know `for<'x,'b> T: Bar1<'x,'b>`. The
|
|
// reason is similar to the previous example: any impl of
|
|
// `T:Foo1<'x>` must show that `for<'b> T: Bar1<'x, 'b>`. So
|
|
// basically we would want to collapse the bound lifetimes from
|
|
// the input (`trait_ref`) and the supertraits.
|
|
//
|
|
// To achieve this in practice is fairly straightforward. Let's
|
|
// consider the more complicated scenario:
|
|
//
|
|
// - We start out with `for<'x> T: Foo1<'x>`. In this case, `'x`
|
|
// has a De Bruijn index of 1. We want to produce `for<'x,'b> T: Bar1<'x,'b>`,
|
|
// where both `'x` and `'b` would have a DB index of 1.
|
|
// The substitution from the input trait-ref is therefore going to be
|
|
// `'a => 'x` (where `'x` has a DB index of 1).
|
|
// - The super-trait-ref is `for<'b> Bar1<'a,'b>`, where `'a` is an
|
|
// early-bound parameter and `'b' is a late-bound parameter with a
|
|
// DB index of 1.
|
|
// - If we replace `'a` with `'x` from the input, it too will have
|
|
// a DB index of 1, and thus we'll have `for<'x,'b> Bar1<'x,'b>`
|
|
// just as we wanted.
|
|
//
|
|
// There is only one catch. If we just apply the substitution `'a
|
|
// => 'x` to `for<'b> Bar1<'a,'b>`, the substitution code will
|
|
// adjust the DB index because we substituting into a binder (it
|
|
// tries to be so smart...) resulting in `for<'x> for<'b>
|
|
// Bar1<'x,'b>` (we have no syntax for this, so use your
|
|
// imagination). Basically the 'x will have DB index of 2 and 'b
|
|
// will have DB index of 1. Not quite what we want. So we apply
|
|
// the substitution to the *contents* of the trait reference,
|
|
// rather than the trait reference itself (put another way, the
|
|
// substitution code expects equal binding levels in the values
|
|
// from the substitution and the value being substituted into, and
|
|
// this trick achieves that).
|
|
|
|
let substs = &trait_ref.skip_binder().substs;
|
|
match *self {
|
|
Predicate::Trait(ref binder) =>
|
|
Predicate::Trait(binder.map_bound(|data| data.subst(tcx, substs))),
|
|
Predicate::Subtype(ref binder) =>
|
|
Predicate::Subtype(binder.map_bound(|data| data.subst(tcx, substs))),
|
|
Predicate::RegionOutlives(ref binder) =>
|
|
Predicate::RegionOutlives(binder.map_bound(|data| data.subst(tcx, substs))),
|
|
Predicate::TypeOutlives(ref binder) =>
|
|
Predicate::TypeOutlives(binder.map_bound(|data| data.subst(tcx, substs))),
|
|
Predicate::Projection(ref binder) =>
|
|
Predicate::Projection(binder.map_bound(|data| data.subst(tcx, substs))),
|
|
Predicate::WellFormed(data) =>
|
|
Predicate::WellFormed(data.subst(tcx, substs)),
|
|
Predicate::ObjectSafe(trait_def_id) =>
|
|
Predicate::ObjectSafe(trait_def_id),
|
|
Predicate::ClosureKind(closure_def_id, closure_substs, kind) =>
|
|
Predicate::ClosureKind(closure_def_id, closure_substs.subst(tcx, substs), kind),
|
|
Predicate::ConstEvaluatable(def_id, const_substs) =>
|
|
Predicate::ConstEvaluatable(def_id, const_substs.subst(tcx, substs)),
|
|
}
|
|
}
|
|
}
|
|
|
|
#[derive(Clone, Copy, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
|
|
pub struct TraitPredicate<'tcx> {
|
|
pub trait_ref: TraitRef<'tcx>
|
|
}
|
|
|
|
pub type PolyTraitPredicate<'tcx> = ty::Binder<TraitPredicate<'tcx>>;
|
|
|
|
impl<'tcx> TraitPredicate<'tcx> {
|
|
pub fn def_id(&self) -> DefId {
|
|
self.trait_ref.def_id
|
|
}
|
|
|
|
pub fn input_types<'a>(&'a self) -> impl DoubleEndedIterator<Item=Ty<'tcx>> + 'a {
|
|
self.trait_ref.input_types()
|
|
}
|
|
|
|
pub fn self_ty(&self) -> Ty<'tcx> {
|
|
self.trait_ref.self_ty()
|
|
}
|
|
}
|
|
|
|
impl<'tcx> PolyTraitPredicate<'tcx> {
|
|
pub fn def_id(&self) -> DefId {
|
|
// ok to skip binder since trait def-id does not care about regions
|
|
self.skip_binder().def_id()
|
|
}
|
|
}
|
|
|
|
#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug, RustcEncodable, RustcDecodable)]
|
|
pub struct OutlivesPredicate<A,B>(pub A, pub B); // `A: B`
|
|
pub type PolyOutlivesPredicate<A,B> = ty::Binder<OutlivesPredicate<A,B>>;
|
|
pub type RegionOutlivesPredicate<'tcx> = OutlivesPredicate<ty::Region<'tcx>,
|
|
ty::Region<'tcx>>;
|
|
pub type TypeOutlivesPredicate<'tcx> = OutlivesPredicate<Ty<'tcx>,
|
|
ty::Region<'tcx>>;
|
|
pub type PolyRegionOutlivesPredicate<'tcx> = ty::Binder<RegionOutlivesPredicate<'tcx>>;
|
|
pub type PolyTypeOutlivesPredicate<'tcx> = ty::Binder<TypeOutlivesPredicate<'tcx>>;
|
|
|
|
#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug, RustcEncodable, RustcDecodable)]
|
|
pub struct SubtypePredicate<'tcx> {
|
|
pub a_is_expected: bool,
|
|
pub a: Ty<'tcx>,
|
|
pub b: Ty<'tcx>
|
|
}
|
|
pub type PolySubtypePredicate<'tcx> = ty::Binder<SubtypePredicate<'tcx>>;
|
|
|
|
/// This kind of predicate has no *direct* correspondent in the
|
|
/// syntax, but it roughly corresponds to the syntactic forms:
|
|
///
|
|
/// 1. `T: TraitRef<..., Item=Type>`
|
|
/// 2. `<T as TraitRef<...>>::Item == Type` (NYI)
|
|
///
|
|
/// In particular, form #1 is "desugared" to the combination of a
|
|
/// normal trait predicate (`T: TraitRef<...>`) and one of these
|
|
/// predicates. Form #2 is a broader form in that it also permits
|
|
/// equality between arbitrary types. Processing an instance of
|
|
/// Form #2 eventually yields one of these `ProjectionPredicate`
|
|
/// instances to normalize the LHS.
|
|
#[derive(Copy, Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
|
|
pub struct ProjectionPredicate<'tcx> {
|
|
pub projection_ty: ProjectionTy<'tcx>,
|
|
pub ty: Ty<'tcx>,
|
|
}
|
|
|
|
pub type PolyProjectionPredicate<'tcx> = Binder<ProjectionPredicate<'tcx>>;
|
|
|
|
impl<'tcx> PolyProjectionPredicate<'tcx> {
|
|
/// Returns the `DefId` of the associated item being projected.
|
|
pub fn item_def_id(&self) -> DefId {
|
|
self.skip_binder().projection_ty.item_def_id
|
|
}
|
|
|
|
pub fn to_poly_trait_ref(&self, tcx: TyCtxt<'_, '_, '_>) -> PolyTraitRef<'tcx> {
|
|
// Note: unlike with `TraitRef::to_poly_trait_ref()`,
|
|
// `self.0.trait_ref` is permitted to have escaping regions.
|
|
// This is because here `self` has a `Binder` and so does our
|
|
// return value, so we are preserving the number of binding
|
|
// levels.
|
|
self.map_bound(|predicate| predicate.projection_ty.trait_ref(tcx))
|
|
}
|
|
|
|
pub fn ty(&self) -> Binder<Ty<'tcx>> {
|
|
self.map_bound(|predicate| predicate.ty)
|
|
}
|
|
|
|
/// The `DefId` of the `TraitItem` for the associated type.
|
|
///
|
|
/// Note that this is not the `DefId` of the `TraitRef` containing this
|
|
/// associated type, which is in `tcx.associated_item(projection_def_id()).container`.
|
|
pub fn projection_def_id(&self) -> DefId {
|
|
// okay to skip binder since trait def-id does not care about regions
|
|
self.skip_binder().projection_ty.item_def_id
|
|
}
|
|
}
|
|
|
|
pub trait ToPolyTraitRef<'tcx> {
|
|
fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx>;
|
|
}
|
|
|
|
impl<'tcx> ToPolyTraitRef<'tcx> for TraitRef<'tcx> {
|
|
fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx> {
|
|
ty::Binder::dummy(self.clone())
|
|
}
|
|
}
|
|
|
|
impl<'tcx> ToPolyTraitRef<'tcx> for PolyTraitPredicate<'tcx> {
|
|
fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx> {
|
|
self.map_bound_ref(|trait_pred| trait_pred.trait_ref)
|
|
}
|
|
}
|
|
|
|
pub trait ToPredicate<'tcx> {
|
|
fn to_predicate(&self) -> Predicate<'tcx>;
|
|
}
|
|
|
|
impl<'tcx> ToPredicate<'tcx> for TraitRef<'tcx> {
|
|
fn to_predicate(&self) -> Predicate<'tcx> {
|
|
ty::Predicate::Trait(ty::Binder::dummy(ty::TraitPredicate {
|
|
trait_ref: self.clone()
|
|
}))
|
|
}
|
|
}
|
|
|
|
impl<'tcx> ToPredicate<'tcx> for PolyTraitRef<'tcx> {
|
|
fn to_predicate(&self) -> Predicate<'tcx> {
|
|
ty::Predicate::Trait(self.to_poly_trait_predicate())
|
|
}
|
|
}
|
|
|
|
impl<'tcx> ToPredicate<'tcx> for PolyRegionOutlivesPredicate<'tcx> {
|
|
fn to_predicate(&self) -> Predicate<'tcx> {
|
|
Predicate::RegionOutlives(self.clone())
|
|
}
|
|
}
|
|
|
|
impl<'tcx> ToPredicate<'tcx> for PolyTypeOutlivesPredicate<'tcx> {
|
|
fn to_predicate(&self) -> Predicate<'tcx> {
|
|
Predicate::TypeOutlives(self.clone())
|
|
}
|
|
}
|
|
|
|
impl<'tcx> ToPredicate<'tcx> for PolyProjectionPredicate<'tcx> {
|
|
fn to_predicate(&self) -> Predicate<'tcx> {
|
|
Predicate::Projection(self.clone())
|
|
}
|
|
}
|
|
|
|
impl<'tcx> Predicate<'tcx> {
|
|
/// Iterates over the types in this predicate. Note that in all
|
|
/// cases this is skipping over a binder, so late-bound regions
|
|
/// with depth 0 are bound by the predicate.
|
|
pub fn walk_tys(&self) -> IntoIter<Ty<'tcx>> {
|
|
let vec: Vec<_> = match *self {
|
|
ty::Predicate::Trait(ref data) => {
|
|
data.skip_binder().input_types().collect()
|
|
}
|
|
ty::Predicate::Subtype(binder) => {
|
|
let SubtypePredicate { a, b, a_is_expected: _ } = binder.skip_binder();
|
|
vec![a, b]
|
|
}
|
|
ty::Predicate::TypeOutlives(binder) => {
|
|
vec![binder.skip_binder().0]
|
|
}
|
|
ty::Predicate::RegionOutlives(..) => {
|
|
vec![]
|
|
}
|
|
ty::Predicate::Projection(ref data) => {
|
|
let inner = data.skip_binder();
|
|
inner.projection_ty.substs.types().chain(Some(inner.ty)).collect()
|
|
}
|
|
ty::Predicate::WellFormed(data) => {
|
|
vec![data]
|
|
}
|
|
ty::Predicate::ObjectSafe(_trait_def_id) => {
|
|
vec![]
|
|
}
|
|
ty::Predicate::ClosureKind(_closure_def_id, closure_substs, _kind) => {
|
|
closure_substs.substs.types().collect()
|
|
}
|
|
ty::Predicate::ConstEvaluatable(_, substs) => {
|
|
substs.types().collect()
|
|
}
|
|
};
|
|
|
|
// FIXME: The only reason to collect into a vector here is that I was
|
|
// too lazy to make the full (somewhat complicated) iterator
|
|
// type that would be needed here. But I wanted this fn to
|
|
// return an iterator conceptually, rather than a `Vec`, so as
|
|
// to be closer to `Ty::walk`.
|
|
vec.into_iter()
|
|
}
|
|
|
|
pub fn to_opt_poly_trait_ref(&self) -> Option<PolyTraitRef<'tcx>> {
|
|
match *self {
|
|
Predicate::Trait(ref t) => {
|
|
Some(t.to_poly_trait_ref())
|
|
}
|
|
Predicate::Projection(..) |
|
|
Predicate::Subtype(..) |
|
|
Predicate::RegionOutlives(..) |
|
|
Predicate::WellFormed(..) |
|
|
Predicate::ObjectSafe(..) |
|
|
Predicate::ClosureKind(..) |
|
|
Predicate::TypeOutlives(..) |
|
|
Predicate::ConstEvaluatable(..) => {
|
|
None
|
|
}
|
|
}
|
|
}
|
|
|
|
pub fn to_opt_type_outlives(&self) -> Option<PolyTypeOutlivesPredicate<'tcx>> {
|
|
match *self {
|
|
Predicate::TypeOutlives(data) => {
|
|
Some(data)
|
|
}
|
|
Predicate::Trait(..) |
|
|
Predicate::Projection(..) |
|
|
Predicate::Subtype(..) |
|
|
Predicate::RegionOutlives(..) |
|
|
Predicate::WellFormed(..) |
|
|
Predicate::ObjectSafe(..) |
|
|
Predicate::ClosureKind(..) |
|
|
Predicate::ConstEvaluatable(..) => {
|
|
None
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/// 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 a `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 substituted with
|
|
/// their values.
|
|
///
|
|
/// Example:
|
|
///
|
|
/// 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)]
|
|
pub struct InstantiatedPredicates<'tcx> {
|
|
pub predicates: Vec<Predicate<'tcx>>,
|
|
}
|
|
|
|
impl<'tcx> InstantiatedPredicates<'tcx> {
|
|
pub fn empty() -> InstantiatedPredicates<'tcx> {
|
|
InstantiatedPredicates { predicates: vec![] }
|
|
}
|
|
|
|
pub fn is_empty(&self) -> bool {
|
|
self.predicates.is_empty()
|
|
}
|
|
}
|
|
|
|
/// "Universes" are used during type- and trait-checking in the
|
|
/// presence of `for<..>` binders to control what sets of names are
|
|
/// visible. Universes are arranged into a tree: the root universe
|
|
/// contains names that are always visible. Each child then adds a new
|
|
/// set of names that are visible, in addition to those of its parent.
|
|
/// We say that the child universe "extends" the parent universe with
|
|
/// new names.
|
|
///
|
|
/// To make this more concrete, consider this program:
|
|
///
|
|
/// ```
|
|
/// struct Foo { }
|
|
/// fn bar<T>(x: T) {
|
|
/// let y: for<'a> fn(&'a u8, Foo) = ...;
|
|
/// }
|
|
/// ```
|
|
///
|
|
/// The struct name `Foo` is in the root universe U0. But the type
|
|
/// parameter `T`, introduced on `bar`, is in an extended universe U1
|
|
/// -- i.e., within `bar`, we can name both `T` and `Foo`, but outside
|
|
/// of `bar`, we cannot name `T`. Then, within the type of `y`, the
|
|
/// region `'a` is in a universe U2 that extends U1, because we can
|
|
/// name it inside the fn type but not outside.
|
|
///
|
|
/// Universes are used to do type- and trait-checking around these
|
|
/// "forall" binders (also called **universal quantification**). The
|
|
/// idea is that when, in the body of `bar`, we refer to `T` as a
|
|
/// type, we aren't referring to any type in particular, but rather a
|
|
/// kind of "fresh" type that is distinct from all other types we have
|
|
/// actually declared. This is called a **placeholder** type, and we
|
|
/// use universes to talk about this. In other words, a type name in
|
|
/// universe 0 always corresponds to some "ground" type that the user
|
|
/// declared, but a type name in a non-zero universe is a placeholder
|
|
/// type -- an idealized representative of "types in general" that we
|
|
/// use for checking generic functions.
|
|
newtype_index! {
|
|
pub struct UniverseIndex {
|
|
DEBUG_FORMAT = "U{}",
|
|
}
|
|
}
|
|
|
|
impl_stable_hash_for!(struct UniverseIndex { private });
|
|
|
|
impl UniverseIndex {
|
|
pub const ROOT: UniverseIndex = UniverseIndex::from_u32_const(0);
|
|
|
|
/// Returns the "next" universe index in order -- this new index
|
|
/// is considered to extend all previous universes. This
|
|
/// corresponds to entering a `forall` quantifier. So, for
|
|
/// example, suppose we have this type in universe `U`:
|
|
///
|
|
/// ```
|
|
/// for<'a> fn(&'a u32)
|
|
/// ```
|
|
///
|
|
/// Once we "enter" into this `for<'a>` quantifier, we are in a
|
|
/// new universe that extends `U` -- in this new universe, we can
|
|
/// name the region `'a`, but that region was not nameable from
|
|
/// `U` because it was not in scope there.
|
|
pub fn next_universe(self) -> UniverseIndex {
|
|
UniverseIndex::from_u32(self.private.checked_add(1).unwrap())
|
|
}
|
|
|
|
/// Returns `true` if `self` can name a name from `other` -- in other words,
|
|
/// if the set of names in `self` is a superset of those in
|
|
/// `other` (`self >= other`).
|
|
pub fn can_name(self, other: UniverseIndex) -> bool {
|
|
self.private >= other.private
|
|
}
|
|
|
|
/// Returns `true` if `self` cannot name some names from `other` -- in other
|
|
/// words, if the set of names in `self` is a strict subset of
|
|
/// those in `other` (`self < other`).
|
|
pub fn cannot_name(self, other: UniverseIndex) -> bool {
|
|
self.private < other.private
|
|
}
|
|
}
|
|
|
|
/// The "placeholder index" fully defines a placeholder region.
|
|
/// Placeholder regions are identified by both a **universe** as well
|
|
/// as a "bound-region" within that universe. The `bound_region` is
|
|
/// basically a name -- distinct bound regions within the same
|
|
/// universe are just two regions with an unknown relationship to one
|
|
/// another.
|
|
#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, PartialOrd, Ord)]
|
|
pub struct Placeholder {
|
|
pub universe: UniverseIndex,
|
|
pub name: BoundRegion,
|
|
}
|
|
|
|
impl_stable_hash_for!(struct Placeholder { universe, name });
|
|
|
|
/// When type checking, we use the `ParamEnv` to track
|
|
/// details about the set of where-clauses that are in scope at this
|
|
/// particular point.
|
|
#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
|
|
pub struct ParamEnv<'tcx> {
|
|
/// Obligations that the caller must satisfy. This is basically
|
|
/// the set of bounds on the in-scope type parameters, translated
|
|
/// into Obligations, and elaborated and normalized.
|
|
pub caller_bounds: &'tcx List<ty::Predicate<'tcx>>,
|
|
|
|
/// Typically, this is `Reveal::UserFacing`, but during codegen we
|
|
/// want `Reveal::All` -- note that this is always paired with an
|
|
/// empty environment. To get that, use `ParamEnv::reveal()`.
|
|
pub reveal: traits::Reveal,
|
|
}
|
|
|
|
impl<'tcx> ParamEnv<'tcx> {
|
|
/// Construct a trait environment suitable for contexts where
|
|
/// there are no where clauses in scope. Hidden types (like `impl
|
|
/// Trait`) are left hidden, so this is suitable for ordinary
|
|
/// type-checking.
|
|
pub fn empty() -> Self {
|
|
Self::new(List::empty(), Reveal::UserFacing)
|
|
}
|
|
|
|
/// Construct a trait environment with no where clauses in scope
|
|
/// where the values of all `impl Trait` and other hidden types
|
|
/// are revealed. This is suitable for monomorphized, post-typeck
|
|
/// environments like codegen or doing optimizations.
|
|
///
|
|
/// N.B. If you want to have predicates in scope, use `ParamEnv::new`,
|
|
/// or invoke `param_env.with_reveal_all()`.
|
|
pub fn reveal_all() -> Self {
|
|
Self::new(List::empty(), Reveal::All)
|
|
}
|
|
|
|
/// Construct a trait environment with the given set of predicates.
|
|
pub fn new(caller_bounds: &'tcx List<ty::Predicate<'tcx>>,
|
|
reveal: Reveal)
|
|
-> Self {
|
|
ty::ParamEnv { caller_bounds, reveal }
|
|
}
|
|
|
|
/// Returns a new parameter environment with the same clauses, but
|
|
/// which "reveals" the true results of projections in all cases
|
|
/// (even for associated types that are specializable). This is
|
|
/// the desired behavior during codegen and certain other special
|
|
/// contexts; normally though we want to use `Reveal::UserFacing`,
|
|
/// which is the default.
|
|
pub fn with_reveal_all(self) -> Self {
|
|
ty::ParamEnv { reveal: Reveal::All, ..self }
|
|
}
|
|
|
|
/// Returns this same environment but with no caller bounds.
|
|
pub fn without_caller_bounds(self) -> Self {
|
|
ty::ParamEnv { caller_bounds: List::empty(), ..self }
|
|
}
|
|
|
|
/// Creates a suitable environment in which to perform trait
|
|
/// queries on the given value. When type-checking, this is simply
|
|
/// the pair of the environment plus value. But when reveal is set to
|
|
/// All, then if `value` does not reference any type parameters, we will
|
|
/// pair it with the empty environment. This improves caching and is generally
|
|
/// invisible.
|
|
///
|
|
/// NB: We preserve the environment when type-checking because it
|
|
/// is possible for the user to have wacky where-clauses like
|
|
/// `where Box<u32>: Copy`, which are clearly never
|
|
/// satisfiable. We generally want to behave as if they were true,
|
|
/// although the surrounding function is never reachable.
|
|
pub fn and<T: TypeFoldable<'tcx>>(self, value: T) -> ParamEnvAnd<'tcx, T> {
|
|
match self.reveal {
|
|
Reveal::UserFacing => {
|
|
ParamEnvAnd {
|
|
param_env: self,
|
|
value,
|
|
}
|
|
}
|
|
|
|
Reveal::All => {
|
|
if value.has_skol()
|
|
|| value.needs_infer()
|
|
|| value.has_param_types()
|
|
|| value.has_self_ty()
|
|
{
|
|
ParamEnvAnd {
|
|
param_env: self,
|
|
value,
|
|
}
|
|
} else {
|
|
ParamEnvAnd {
|
|
param_env: self.without_caller_bounds(),
|
|
value,
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
|
|
pub struct ParamEnvAnd<'tcx, T> {
|
|
pub param_env: ParamEnv<'tcx>,
|
|
pub value: T,
|
|
}
|
|
|
|
impl<'tcx, T> ParamEnvAnd<'tcx, T> {
|
|
pub fn into_parts(self) -> (ParamEnv<'tcx>, T) {
|
|
(self.param_env, self.value)
|
|
}
|
|
}
|
|
|
|
impl<'a, 'gcx, T> HashStable<StableHashingContext<'a>> for ParamEnvAnd<'gcx, T>
|
|
where T: HashStable<StableHashingContext<'a>>
|
|
{
|
|
fn hash_stable<W: StableHasherResult>(&self,
|
|
hcx: &mut StableHashingContext<'a>,
|
|
hasher: &mut StableHasher<W>) {
|
|
let ParamEnvAnd {
|
|
ref param_env,
|
|
ref value
|
|
} = *self;
|
|
|
|
param_env.hash_stable(hcx, hasher);
|
|
value.hash_stable(hcx, hasher);
|
|
}
|
|
}
|
|
|
|
#[derive(Copy, Clone, Debug)]
|
|
pub struct Destructor {
|
|
/// The def-id of the destructor method
|
|
pub did: DefId,
|
|
}
|
|
|
|
bitflags! {
|
|
pub struct AdtFlags: u32 {
|
|
const NO_ADT_FLAGS = 0;
|
|
const IS_ENUM = 1 << 0;
|
|
const IS_PHANTOM_DATA = 1 << 1;
|
|
const IS_FUNDAMENTAL = 1 << 2;
|
|
const IS_UNION = 1 << 3;
|
|
const IS_BOX = 1 << 4;
|
|
/// Indicates whether the type is an `Arc`.
|
|
const IS_ARC = 1 << 5;
|
|
/// Indicates whether the type is an `Rc`.
|
|
const IS_RC = 1 << 6;
|
|
/// 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 << 7;
|
|
}
|
|
}
|
|
|
|
bitflags! {
|
|
pub struct VariantFlags: u32 {
|
|
const NO_VARIANT_FLAGS = 0;
|
|
/// Indicates whether the field list of this variant is `#[non_exhaustive]`.
|
|
const IS_FIELD_LIST_NON_EXHAUSTIVE = 1 << 0;
|
|
}
|
|
}
|
|
|
|
#[derive(Debug)]
|
|
pub struct VariantDef {
|
|
/// The variant's DefId. If this is a tuple-like struct,
|
|
/// this is the DefId of the struct's ctor.
|
|
pub did: DefId,
|
|
pub name: Name, // struct's name if this is a struct
|
|
pub discr: VariantDiscr,
|
|
pub fields: Vec<FieldDef>,
|
|
pub ctor_kind: CtorKind,
|
|
flags: VariantFlags,
|
|
}
|
|
|
|
impl<'a, 'gcx, 'tcx> VariantDef {
|
|
/// Create a new `VariantDef`.
|
|
///
|
|
/// - `did` is the DefId used for the variant - for tuple-structs, it is the constructor DefId,
|
|
/// and for everything else, it is the variant DefId.
|
|
/// - `attribute_def_id` is the DefId that has the variant's attributes.
|
|
/// this is the struct DefId for structs, and the variant DefId for variants.
|
|
///
|
|
/// Note that we *could* use the constructor DefId, because the constructor attributes
|
|
/// redirect to the base attributes, but compiling a small crate requires
|
|
/// loading the AdtDefs 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.
|
|
pub fn new(tcx: TyCtxt<'a, 'gcx, 'tcx>,
|
|
did: DefId,
|
|
name: Name,
|
|
discr: VariantDiscr,
|
|
fields: Vec<FieldDef>,
|
|
adt_kind: AdtKind,
|
|
ctor_kind: CtorKind,
|
|
attribute_def_id: DefId)
|
|
-> Self
|
|
{
|
|
debug!("VariantDef::new({:?}, {:?}, {:?}, {:?}, {:?}, {:?}, {:?})", did, name, discr,
|
|
fields, adt_kind, ctor_kind, attribute_def_id);
|
|
let mut flags = VariantFlags::NO_VARIANT_FLAGS;
|
|
if adt_kind == AdtKind::Struct && tcx.has_attr(attribute_def_id, "non_exhaustive") {
|
|
debug!("found non-exhaustive field list for {:?}", did);
|
|
flags = flags | VariantFlags::IS_FIELD_LIST_NON_EXHAUSTIVE;
|
|
}
|
|
VariantDef {
|
|
did,
|
|
name,
|
|
discr,
|
|
fields,
|
|
ctor_kind,
|
|
flags
|
|
}
|
|
}
|
|
|
|
#[inline]
|
|
pub fn is_field_list_non_exhaustive(&self) -> bool {
|
|
self.flags.intersects(VariantFlags::IS_FIELD_LIST_NON_EXHAUSTIVE)
|
|
}
|
|
}
|
|
|
|
impl_stable_hash_for!(struct VariantDef {
|
|
did,
|
|
name,
|
|
discr,
|
|
fields,
|
|
ctor_kind,
|
|
flags
|
|
});
|
|
|
|
#[derive(Copy, Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)]
|
|
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)]
|
|
pub struct FieldDef {
|
|
pub did: DefId,
|
|
pub ident: Ident,
|
|
pub vis: Visibility,
|
|
}
|
|
|
|
/// The definition of an abstract data type - a struct or enum.
|
|
///
|
|
/// These are all interned (by intern_adt_def) into the adt_defs
|
|
/// table.
|
|
pub struct AdtDef {
|
|
pub did: DefId,
|
|
pub variants: IndexVec<self::layout::VariantIdx, VariantDef>,
|
|
flags: AdtFlags,
|
|
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 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<'tcx> serialize::UseSpecializedEncodable for &'tcx AdtDef {
|
|
fn default_encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
|
|
self.did.encode(s)
|
|
}
|
|
}
|
|
|
|
impl<'tcx> serialize::UseSpecializedDecodable for &'tcx AdtDef {}
|
|
|
|
|
|
impl<'a> HashStable<StableHashingContext<'a>> for AdtDef {
|
|
fn hash_stable<W: StableHasherResult>(&self,
|
|
hcx: &mut StableHashingContext<'a>,
|
|
hasher: &mut StableHasher<W>) {
|
|
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(RustcEncodable, RustcDecodable, Default)]
|
|
pub struct ReprFlags: u8 {
|
|
const IS_C = 1 << 0;
|
|
const IS_SIMD = 1 << 1;
|
|
const IS_TRANSPARENT = 1 << 2;
|
|
// Internal only for now. If true, don't reorder fields.
|
|
const IS_LINEAR = 1 << 3;
|
|
|
|
// Any of these flags being set prevent field reordering optimisation.
|
|
const IS_UNOPTIMISABLE = ReprFlags::IS_C.bits |
|
|
ReprFlags::IS_SIMD.bits |
|
|
ReprFlags::IS_LINEAR.bits;
|
|
}
|
|
}
|
|
|
|
impl_stable_hash_for!(struct ReprFlags {
|
|
bits
|
|
});
|
|
|
|
|
|
|
|
/// Represents the repr options provided by the user,
|
|
#[derive(Copy, Clone, Debug, Eq, PartialEq, RustcEncodable, RustcDecodable, Default)]
|
|
pub struct ReprOptions {
|
|
pub int: Option<attr::IntType>,
|
|
pub align: u32,
|
|
pub pack: u32,
|
|
pub flags: ReprFlags,
|
|
}
|
|
|
|
impl_stable_hash_for!(struct ReprOptions {
|
|
align,
|
|
pack,
|
|
int,
|
|
flags
|
|
});
|
|
|
|
impl ReprOptions {
|
|
pub fn new(tcx: TyCtxt<'_, '_, '_>, did: DefId) -> ReprOptions {
|
|
let mut flags = ReprFlags::empty();
|
|
let mut size = None;
|
|
let mut max_align = 0;
|
|
let mut min_pack = 0;
|
|
for attr in tcx.get_attrs(did).iter() {
|
|
for r in attr::find_repr_attrs(&tcx.sess.parse_sess, attr) {
|
|
flags.insert(match r {
|
|
attr::ReprC => ReprFlags::IS_C,
|
|
attr::ReprPacked(pack) => {
|
|
min_pack = if min_pack > 0 {
|
|
cmp::min(pack, min_pack)
|
|
} else {
|
|
pack
|
|
};
|
|
ReprFlags::empty()
|
|
},
|
|
attr::ReprTransparent => ReprFlags::IS_TRANSPARENT,
|
|
attr::ReprSimd => ReprFlags::IS_SIMD,
|
|
attr::ReprInt(i) => {
|
|
size = Some(i);
|
|
ReprFlags::empty()
|
|
},
|
|
attr::ReprAlign(align) => {
|
|
max_align = cmp::max(align, max_align);
|
|
ReprFlags::empty()
|
|
},
|
|
});
|
|
}
|
|
}
|
|
|
|
// This is here instead of layout because the choice must make it into metadata.
|
|
if !tcx.consider_optimizing(|| format!("Reorder fields of {:?}", tcx.item_path_str(did))) {
|
|
flags.insert(ReprFlags::IS_LINEAR);
|
|
}
|
|
ReprOptions { int: size, align: max_align, pack: min_pack, flags: flags }
|
|
}
|
|
|
|
#[inline]
|
|
pub fn simd(&self) -> bool { self.flags.contains(ReprFlags::IS_SIMD) }
|
|
#[inline]
|
|
pub fn c(&self) -> bool { self.flags.contains(ReprFlags::IS_C) }
|
|
#[inline]
|
|
pub fn packed(&self) -> bool { self.pack > 0 }
|
|
#[inline]
|
|
pub fn transparent(&self) -> bool { self.flags.contains(ReprFlags::IS_TRANSPARENT) }
|
|
#[inline]
|
|
pub fn linear(&self) -> bool { self.flags.contains(ReprFlags::IS_LINEAR) }
|
|
|
|
pub fn discr_type(&self) -> attr::IntType {
|
|
self.int.unwrap_or(attr::SignedInt(ast::IntTy::Isize))
|
|
}
|
|
|
|
/// Returns `true` if this `#[repr()]` should inhabit "smart enum
|
|
/// layout" optimizations, such as representing `Foo<&T>` as a
|
|
/// single pointer.
|
|
pub fn inhibit_enum_layout_opt(&self) -> bool {
|
|
self.c() || self.int.is_some()
|
|
}
|
|
|
|
/// Returns `true` if this `#[repr()]` should inhibit struct field reordering
|
|
/// optimizations, such as with repr(C) or repr(packed(1)).
|
|
pub fn inhibit_struct_field_reordering_opt(&self) -> bool {
|
|
!(self.flags & ReprFlags::IS_UNOPTIMISABLE).is_empty() || (self.pack == 1)
|
|
}
|
|
}
|
|
|
|
impl<'a, 'gcx, 'tcx> 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;
|
|
let attrs = tcx.get_attrs(did);
|
|
if attr::contains_name(&attrs, "fundamental") {
|
|
flags = flags | AdtFlags::IS_FUNDAMENTAL;
|
|
}
|
|
if Some(did) == tcx.lang_items().phantom_data() {
|
|
flags = flags | AdtFlags::IS_PHANTOM_DATA;
|
|
}
|
|
if Some(did) == tcx.lang_items().owned_box() {
|
|
flags = flags | AdtFlags::IS_BOX;
|
|
}
|
|
if Some(did) == tcx.lang_items().arc() {
|
|
flags = flags | AdtFlags::IS_ARC;
|
|
}
|
|
if Some(did) == tcx.lang_items().rc() {
|
|
flags = flags | AdtFlags::IS_RC;
|
|
}
|
|
if kind == AdtKind::Enum && tcx.has_attr(did, "non_exhaustive") {
|
|
debug!("found non-exhaustive variant list for {:?}", did);
|
|
flags = flags | AdtFlags::IS_VARIANT_LIST_NON_EXHAUSTIVE;
|
|
}
|
|
match kind {
|
|
AdtKind::Enum => flags = flags | AdtFlags::IS_ENUM,
|
|
AdtKind::Union => flags = flags | AdtFlags::IS_UNION,
|
|
AdtKind::Struct => {}
|
|
}
|
|
AdtDef {
|
|
did,
|
|
variants,
|
|
flags,
|
|
repr,
|
|
}
|
|
}
|
|
|
|
#[inline]
|
|
pub fn is_struct(&self) -> bool {
|
|
!self.is_union() && !self.is_enum()
|
|
}
|
|
|
|
#[inline]
|
|
pub fn is_union(&self) -> bool {
|
|
self.flags.intersects(AdtFlags::IS_UNION)
|
|
}
|
|
|
|
#[inline]
|
|
pub fn is_enum(&self) -> bool {
|
|
self.flags.intersects(AdtFlags::IS_ENUM)
|
|
}
|
|
|
|
#[inline]
|
|
pub fn is_variant_list_non_exhaustive(&self) -> bool {
|
|
self.flags.intersects(AdtFlags::IS_VARIANT_LIST_NON_EXHAUSTIVE)
|
|
}
|
|
|
|
/// Returns the kind of the ADT - Struct or Enum.
|
|
#[inline]
|
|
pub fn adt_kind(&self) -> AdtKind {
|
|
if self.is_enum() {
|
|
AdtKind::Enum
|
|
} else if self.is_union() {
|
|
AdtKind::Union
|
|
} else {
|
|
AdtKind::Struct
|
|
}
|
|
}
|
|
|
|
pub fn descr(&self) -> &'static str {
|
|
match self.adt_kind() {
|
|
AdtKind::Struct => "struct",
|
|
AdtKind::Union => "union",
|
|
AdtKind::Enum => "enum",
|
|
}
|
|
}
|
|
|
|
pub fn variant_descr(&self) -> &'static str {
|
|
match self.adt_kind() {
|
|
AdtKind::Struct => "struct",
|
|
AdtKind::Union => "union",
|
|
AdtKind::Enum => "variant",
|
|
}
|
|
}
|
|
|
|
/// Returns whether this type is #[fundamental] for the purposes
|
|
/// of coherence checking.
|
|
#[inline]
|
|
pub fn is_fundamental(&self) -> bool {
|
|
self.flags.intersects(AdtFlags::IS_FUNDAMENTAL)
|
|
}
|
|
|
|
/// Returns `true` if this is PhantomData<T>.
|
|
#[inline]
|
|
pub fn is_phantom_data(&self) -> bool {
|
|
self.flags.intersects(AdtFlags::IS_PHANTOM_DATA)
|
|
}
|
|
|
|
/// Returns `true` if this is `Arc<T>`.
|
|
pub fn is_arc(&self) -> bool {
|
|
self.flags.intersects(AdtFlags::IS_ARC)
|
|
}
|
|
|
|
/// Returns `true` if this is `Rc<T>`.
|
|
pub fn is_rc(&self) -> bool {
|
|
self.flags.intersects(AdtFlags::IS_RC)
|
|
}
|
|
|
|
/// Returns `true` if this is Box<T>.
|
|
#[inline]
|
|
pub fn is_box(&self) -> bool {
|
|
self.flags.intersects(AdtFlags::IS_BOX)
|
|
}
|
|
|
|
/// Returns whether this type has a destructor.
|
|
pub fn has_dtor(&self, tcx: TyCtxt<'a, 'gcx, '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<'a, 'gcx, 'tcx>) -> GenericPredicates<'gcx> {
|
|
tcx.predicates_of(self.did)
|
|
}
|
|
|
|
/// Returns an iterator over all fields contained
|
|
/// by this ADT.
|
|
#[inline]
|
|
pub fn all_fields<'s>(&'s self) -> impl Iterator<Item = &'s FieldDef> {
|
|
self.variants.iter().flat_map(|v| v.fields.iter())
|
|
}
|
|
|
|
pub fn is_payloadfree(&self) -> bool {
|
|
!self.variants.is_empty() &&
|
|
self.variants.iter().all(|v| v.fields.is_empty())
|
|
}
|
|
|
|
pub fn variant_with_id(&self, vid: DefId) -> &VariantDef {
|
|
self.variants
|
|
.iter()
|
|
.find(|v| v.did == vid)
|
|
.expect("variant_with_id: unknown variant")
|
|
}
|
|
|
|
pub fn variant_index_with_id(&self, vid: DefId) -> usize {
|
|
self.variants
|
|
.iter()
|
|
.position(|v| v.did == vid)
|
|
.expect("variant_index_with_id: unknown variant")
|
|
}
|
|
|
|
pub fn variant_of_def(&self, def: Def) -> &VariantDef {
|
|
match def {
|
|
Def::Variant(vid) | Def::VariantCtor(vid, ..) => self.variant_with_id(vid),
|
|
Def::Struct(..) | Def::StructCtor(..) | Def::Union(..) |
|
|
Def::TyAlias(..) | Def::AssociatedTy(..) | Def::SelfTy(..) |
|
|
Def::SelfCtor(..) => self.non_enum_variant(),
|
|
_ => bug!("unexpected def {:?} in variant_of_def", def)
|
|
}
|
|
}
|
|
|
|
#[inline]
|
|
pub fn eval_explicit_discr(
|
|
&self,
|
|
tcx: TyCtxt<'a, 'gcx, 'tcx>,
|
|
expr_did: DefId,
|
|
) -> Option<Discr<'tcx>> {
|
|
let param_env = ParamEnv::empty();
|
|
let repr_type = self.repr.discr_type();
|
|
let substs = Substs::identity_for_item(tcx.global_tcx(), expr_did);
|
|
let instance = ty::Instance::new(expr_did, substs);
|
|
let cid = GlobalId {
|
|
instance,
|
|
promoted: None
|
|
};
|
|
match tcx.const_eval(param_env.and(cid)) {
|
|
Ok(val) => {
|
|
// FIXME: Find the right type and use it instead of `val.ty` here
|
|
if let Some(b) = val.assert_bits(tcx.global_tcx(), param_env.and(val.ty)) {
|
|
trace!("discriminants: {} ({:?})", b, repr_type);
|
|
Some(Discr {
|
|
val: b,
|
|
ty: val.ty,
|
|
})
|
|
} else {
|
|
info!("invalid enum discriminant: {:#?}", val);
|
|
::mir::interpret::struct_error(
|
|
tcx.at(tcx.def_span(expr_did)),
|
|
"constant evaluation of enum discriminant resulted in non-integer",
|
|
).emit();
|
|
None
|
|
}
|
|
}
|
|
Err(ErrorHandled::Reported) => {
|
|
if !expr_did.is_local() {
|
|
span_bug!(tcx.def_span(expr_did),
|
|
"variant discriminant evaluation succeeded \
|
|
in its crate but failed locally");
|
|
}
|
|
None
|
|
}
|
|
Err(ErrorHandled::TooGeneric) => span_bug!(
|
|
tcx.def_span(expr_did),
|
|
"enum discriminant depends on generic arguments",
|
|
),
|
|
}
|
|
}
|
|
|
|
#[inline]
|
|
pub fn discriminants(
|
|
&'a self,
|
|
tcx: TyCtxt<'a, 'gcx, 'tcx>,
|
|
) -> impl Iterator<Item=(VariantIdx, Discr<'tcx>)> + Captures<'gcx> + 'a {
|
|
let repr_type = self.repr.discr_type();
|
|
let initial = repr_type.initial_discriminant(tcx.global_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)
|
|
})
|
|
}
|
|
|
|
/// Compute 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.
|
|
pub fn discriminant_for_variant(&self,
|
|
tcx: TyCtxt<'a, 'gcx, 'tcx>,
|
|
variant_index: VariantIdx)
|
|
-> Discr<'tcx> {
|
|
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.global_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) {
|
|
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<'a, 'gcx, '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<'a, 'gcx, 'tcx>) -> &'tcx [Ty<'tcx>] {
|
|
match tcx.try_adt_sized_constraint(DUMMY_SP, self.did) {
|
|
Ok(tys) => tys,
|
|
Err(mut bug) => {
|
|
debug!("adt_sized_constraint: {:?} is recursive", self);
|
|
// This should be reported as an error by `check_representable`.
|
|
//
|
|
// Consider the type as Sized in the meanwhile to avoid
|
|
// further errors. Delay our `bug` diagnostic here to get
|
|
// emitted later as well in case we accidentally otherwise don't
|
|
// emit an error.
|
|
bug.delay_as_bug();
|
|
tcx.intern_type_list(&[tcx.types.err])
|
|
}
|
|
}
|
|
}
|
|
|
|
fn sized_constraint_for_ty(&self,
|
|
tcx: TyCtxt<'a, 'tcx, 'tcx>,
|
|
ty: Ty<'tcx>)
|
|
-> Vec<Ty<'tcx>> {
|
|
let result = match ty.sty {
|
|
Bool | Char | Int(..) | Uint(..) | Float(..) |
|
|
RawPtr(..) | Ref(..) | FnDef(..) | FnPtr(_) |
|
|
Array(..) | Closure(..) | Generator(..) | Never => {
|
|
vec![]
|
|
}
|
|
|
|
Str |
|
|
Dynamic(..) |
|
|
Slice(_) |
|
|
Foreign(..) |
|
|
Error |
|
|
GeneratorWitness(..) => {
|
|
// these are never sized - return the target type
|
|
vec![ty]
|
|
}
|
|
|
|
Tuple(ref tys) => {
|
|
match tys.last() {
|
|
None => vec![],
|
|
Some(ty) => self.sized_constraint_for_ty(tcx, ty)
|
|
}
|
|
}
|
|
|
|
Adt(adt, substs) => {
|
|
// recursive case
|
|
let adt_tys = adt.sized_constraint(tcx);
|
|
debug!("sized_constraint_for_ty({:?}) intermediate = {:?}",
|
|
ty, adt_tys);
|
|
adt_tys.iter()
|
|
.map(|ty| ty.subst(tcx, substs))
|
|
.flat_map(|ty| self.sized_constraint_for_ty(tcx, ty))
|
|
.collect()
|
|
}
|
|
|
|
Projection(..) | Opaque(..) => {
|
|
// must calculate explicitly.
|
|
// FIXME: consider special-casing always-Sized projections
|
|
vec![ty]
|
|
}
|
|
|
|
UnnormalizedProjection(..) => bug!("only used with chalk-engine"),
|
|
|
|
Param(..) => {
|
|
// perf hack: if there is a `T: Sized` bound, then
|
|
// we know that `T` is Sized and do not need to check
|
|
// it on the impl.
|
|
|
|
let sized_trait = match tcx.lang_items().sized_trait() {
|
|
Some(x) => x,
|
|
_ => return vec![ty]
|
|
};
|
|
let sized_predicate = Binder::dummy(TraitRef {
|
|
def_id: sized_trait,
|
|
substs: tcx.mk_substs_trait(ty, &[])
|
|
}).to_predicate();
|
|
let predicates = tcx.predicates_of(self.did).predicates;
|
|
if predicates.into_iter().any(|(p, _)| p == sized_predicate) {
|
|
vec![]
|
|
} else {
|
|
vec![ty]
|
|
}
|
|
}
|
|
|
|
Bound(..) |
|
|
Infer(..) => {
|
|
bug!("unexpected type `{:?}` in sized_constraint_for_ty",
|
|
ty)
|
|
}
|
|
};
|
|
debug!("sized_constraint_for_ty({:?}) = {:?}", ty, result);
|
|
result
|
|
}
|
|
}
|
|
|
|
impl<'a, 'gcx, 'tcx> FieldDef {
|
|
pub fn ty(&self, tcx: TyCtxt<'a, 'gcx, 'tcx>, subst: &Substs<'tcx>) -> Ty<'tcx> {
|
|
tcx.type_of(self.did).subst(tcx, subst)
|
|
}
|
|
}
|
|
|
|
/// Represents the various closure traits in the Rust language. This
|
|
/// will determine the type of the environment (`self`, in the
|
|
/// desuaring) argument that the closure expects.
|
|
///
|
|
/// You can get the environment type of a closure using
|
|
/// `tcx.closure_env_ty()`.
|
|
#[derive(Clone, Copy, PartialOrd, Ord, PartialEq, Eq, Hash, Debug, RustcEncodable, RustcDecodable)]
|
|
pub enum ClosureKind {
|
|
// Warning: Ordering is significant here! The ordering is chosen
|
|
// because the trait Fn is a subtrait of FnMut and so in turn, and
|
|
// hence we order it so that Fn < FnMut < FnOnce.
|
|
Fn,
|
|
FnMut,
|
|
FnOnce,
|
|
}
|
|
|
|
impl<'a, 'tcx> ClosureKind {
|
|
// This is the initial value used when doing upvar inference.
|
|
pub const LATTICE_BOTTOM: ClosureKind = ClosureKind::Fn;
|
|
|
|
pub fn trait_did(&self, tcx: TyCtxt<'a, 'tcx, 'tcx>) -> DefId {
|
|
match *self {
|
|
ClosureKind::Fn => tcx.require_lang_item(FnTraitLangItem),
|
|
ClosureKind::FnMut => {
|
|
tcx.require_lang_item(FnMutTraitLangItem)
|
|
}
|
|
ClosureKind::FnOnce => {
|
|
tcx.require_lang_item(FnOnceTraitLangItem)
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Returns `true` if this a type that impls this closure kind
|
|
/// must also implement `other`.
|
|
pub fn extends(self, other: ty::ClosureKind) -> bool {
|
|
match (self, other) {
|
|
(ClosureKind::Fn, ClosureKind::Fn) => true,
|
|
(ClosureKind::Fn, ClosureKind::FnMut) => true,
|
|
(ClosureKind::Fn, ClosureKind::FnOnce) => true,
|
|
(ClosureKind::FnMut, ClosureKind::FnMut) => true,
|
|
(ClosureKind::FnMut, ClosureKind::FnOnce) => true,
|
|
(ClosureKind::FnOnce, ClosureKind::FnOnce) => true,
|
|
_ => false,
|
|
}
|
|
}
|
|
|
|
/// Returns the representative scalar type for this closure kind.
|
|
/// See `TyS::to_opt_closure_kind` for more details.
|
|
pub fn to_ty(self, tcx: TyCtxt<'_, '_, 'tcx>) -> Ty<'tcx> {
|
|
match self {
|
|
ty::ClosureKind::Fn => tcx.types.i8,
|
|
ty::ClosureKind::FnMut => tcx.types.i16,
|
|
ty::ClosureKind::FnOnce => tcx.types.i32,
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'tcx> TyS<'tcx> {
|
|
/// 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:
|
|
///
|
|
/// ```notrust
|
|
/// isize => { isize }
|
|
/// Foo<Bar<isize>> => { Foo<Bar<isize>>, Bar<isize>, isize }
|
|
/// [isize] => { [isize], isize }
|
|
/// ```
|
|
pub fn walk(&'tcx self) -> TypeWalker<'tcx> {
|
|
TypeWalker::new(self)
|
|
}
|
|
|
|
/// Iterator that walks the immediate children of `self`. Hence
|
|
/// `Foo<Bar<i32>, u32>` yields the sequence `[Bar<i32>, u32]`
|
|
/// (but not `i32`, like `walk`).
|
|
pub fn walk_shallow(&'tcx self) -> smallvec::IntoIter<walk::TypeWalkerArray<'tcx>> {
|
|
walk::walk_shallow(self)
|
|
}
|
|
|
|
/// Walks `ty` and any types appearing within `ty`, invoking the
|
|
/// callback `f` on each type. If the callback returns false, then the
|
|
/// children of the current type are ignored.
|
|
///
|
|
/// Note: prefer `ty.walk()` where possible.
|
|
pub fn maybe_walk<F>(&'tcx self, mut f: F)
|
|
where F: FnMut(Ty<'tcx>) -> bool
|
|
{
|
|
let mut walker = self.walk();
|
|
while let Some(ty) = walker.next() {
|
|
if !f(ty) {
|
|
walker.skip_current_subtree();
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
impl BorrowKind {
|
|
pub fn from_mutbl(m: hir::Mutability) -> BorrowKind {
|
|
match m {
|
|
hir::MutMutable => MutBorrow,
|
|
hir::MutImmutable => ImmBorrow,
|
|
}
|
|
}
|
|
|
|
/// Returns a mutability `m` such that an `&m T` pointer could be used to obtain this borrow
|
|
/// kind. Because borrow kinds are richer than mutabilities, we sometimes have to pick a
|
|
/// mutability that is stronger than necessary so that it at least *would permit* the borrow in
|
|
/// question.
|
|
pub fn to_mutbl_lossy(self) -> hir::Mutability {
|
|
match self {
|
|
MutBorrow => hir::MutMutable,
|
|
ImmBorrow => hir::MutImmutable,
|
|
|
|
// We have no type corresponding to a unique imm borrow, so
|
|
// use `&mut`. It gives all the capabilities of an `&uniq`
|
|
// and hence is a safe "over approximation".
|
|
UniqueImmBorrow => hir::MutMutable,
|
|
}
|
|
}
|
|
|
|
pub fn to_user_str(&self) -> &'static str {
|
|
match *self {
|
|
MutBorrow => "mutable",
|
|
ImmBorrow => "immutable",
|
|
UniqueImmBorrow => "uniquely immutable",
|
|
}
|
|
}
|
|
}
|
|
|
|
#[derive(Debug, Clone)]
|
|
pub enum Attributes<'gcx> {
|
|
Owned(Lrc<[ast::Attribute]>),
|
|
Borrowed(&'gcx [ast::Attribute])
|
|
}
|
|
|
|
impl<'gcx> ::std::ops::Deref for Attributes<'gcx> {
|
|
type Target = [ast::Attribute];
|
|
|
|
fn deref(&self) -> &[ast::Attribute] {
|
|
match self {
|
|
&Attributes::Owned(ref data) => &data,
|
|
&Attributes::Borrowed(data) => data
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
|
|
pub fn body_tables(self, body: hir::BodyId) -> &'gcx TypeckTables<'gcx> {
|
|
self.typeck_tables_of(self.hir.body_owner_def_id(body))
|
|
}
|
|
|
|
/// Returns an iterator of the def-ids for all body-owners in this
|
|
/// crate. If you would prefer to iterate over the bodies
|
|
/// themselves, you can do `self.hir.krate().body_ids.iter()`.
|
|
pub fn body_owners(
|
|
self,
|
|
) -> impl Iterator<Item = DefId> + Captures<'tcx> + Captures<'gcx> + 'a {
|
|
self.hir.krate()
|
|
.body_ids
|
|
.iter()
|
|
.map(move |&body_id| self.hir.body_owner_def_id(body_id))
|
|
}
|
|
|
|
pub fn par_body_owners<F: Fn(DefId) + sync::Sync + sync::Send>(self, f: F) {
|
|
par_iter(&self.hir.krate().body_ids).for_each(|&body_id| {
|
|
f(self.hir.body_owner_def_id(body_id))
|
|
});
|
|
}
|
|
|
|
pub fn expr_span(self, id: NodeId) -> Span {
|
|
match self.hir.find(id) {
|
|
Some(Node::Expr(e)) => {
|
|
e.span
|
|
}
|
|
Some(f) => {
|
|
bug!("Node id {} is not an expr: {:?}", id, f);
|
|
}
|
|
None => {
|
|
bug!("Node id {} is not present in the node map", id);
|
|
}
|
|
}
|
|
}
|
|
|
|
pub fn provided_trait_methods(self, id: DefId) -> Vec<AssociatedItem> {
|
|
self.associated_items(id)
|
|
.filter(|item| item.kind == AssociatedKind::Method && item.defaultness.has_value())
|
|
.collect()
|
|
}
|
|
|
|
pub fn trait_relevant_for_never(self, did: DefId) -> bool {
|
|
self.associated_items(did).any(|item| {
|
|
item.relevant_for_never()
|
|
})
|
|
}
|
|
|
|
pub fn opt_associated_item(self, def_id: DefId) -> Option<AssociatedItem> {
|
|
let is_associated_item = if let Some(node_id) = self.hir.as_local_node_id(def_id) {
|
|
match self.hir.get(node_id) {
|
|
Node::TraitItem(_) | Node::ImplItem(_) => true,
|
|
_ => false,
|
|
}
|
|
} else {
|
|
match self.describe_def(def_id).expect("no def for def-id") {
|
|
Def::AssociatedConst(_) | Def::Method(_) | Def::AssociatedTy(_) => true,
|
|
_ => false,
|
|
}
|
|
};
|
|
|
|
if is_associated_item {
|
|
Some(self.associated_item(def_id))
|
|
} else {
|
|
None
|
|
}
|
|
}
|
|
|
|
fn associated_item_from_trait_item_ref(self,
|
|
parent_def_id: DefId,
|
|
parent_vis: &hir::Visibility,
|
|
trait_item_ref: &hir::TraitItemRef)
|
|
-> AssociatedItem {
|
|
let def_id = self.hir.local_def_id(trait_item_ref.id.node_id);
|
|
let (kind, has_self) = match trait_item_ref.kind {
|
|
hir::AssociatedItemKind::Const => (ty::AssociatedKind::Const, false),
|
|
hir::AssociatedItemKind::Method { has_self } => {
|
|
(ty::AssociatedKind::Method, has_self)
|
|
}
|
|
hir::AssociatedItemKind::Type => (ty::AssociatedKind::Type, false),
|
|
hir::AssociatedItemKind::Existential => bug!("only impls can have existentials"),
|
|
};
|
|
|
|
AssociatedItem {
|
|
ident: trait_item_ref.ident,
|
|
kind,
|
|
// Visibility of trait items is inherited from their traits.
|
|
vis: Visibility::from_hir(parent_vis, trait_item_ref.id.node_id, self),
|
|
defaultness: trait_item_ref.defaultness,
|
|
def_id,
|
|
container: TraitContainer(parent_def_id),
|
|
method_has_self_argument: has_self
|
|
}
|
|
}
|
|
|
|
fn associated_item_from_impl_item_ref(self,
|
|
parent_def_id: DefId,
|
|
impl_item_ref: &hir::ImplItemRef)
|
|
-> AssociatedItem {
|
|
let def_id = self.hir.local_def_id(impl_item_ref.id.node_id);
|
|
let (kind, has_self) = match impl_item_ref.kind {
|
|
hir::AssociatedItemKind::Const => (ty::AssociatedKind::Const, false),
|
|
hir::AssociatedItemKind::Method { has_self } => {
|
|
(ty::AssociatedKind::Method, has_self)
|
|
}
|
|
hir::AssociatedItemKind::Type => (ty::AssociatedKind::Type, false),
|
|
hir::AssociatedItemKind::Existential => (ty::AssociatedKind::Existential, false),
|
|
};
|
|
|
|
AssociatedItem {
|
|
ident: impl_item_ref.ident,
|
|
kind,
|
|
// Visibility of trait impl items doesn't matter.
|
|
vis: ty::Visibility::from_hir(&impl_item_ref.vis, impl_item_ref.id.node_id, self),
|
|
defaultness: impl_item_ref.defaultness,
|
|
def_id,
|
|
container: ImplContainer(parent_def_id),
|
|
method_has_self_argument: has_self
|
|
}
|
|
}
|
|
|
|
pub fn field_index(self, node_id: NodeId, tables: &TypeckTables<'_>) -> usize {
|
|
let hir_id = self.hir.node_to_hir_id(node_id);
|
|
tables.field_indices().get(hir_id).cloned().expect("no index for a field")
|
|
}
|
|
|
|
pub fn find_field_index(self, ident: Ident, variant: &VariantDef) -> Option<usize> {
|
|
variant.fields.iter().position(|field| {
|
|
self.adjust_ident(ident, variant.did, DUMMY_NODE_ID).0 == field.ident.modern()
|
|
})
|
|
}
|
|
|
|
pub fn associated_items(
|
|
self,
|
|
def_id: DefId,
|
|
) -> AssociatedItemsIterator<'a, 'gcx, 'tcx> {
|
|
// Ideally, we would use `-> impl Iterator` here, but it falls
|
|
// afoul of the conservative "capture [restrictions]" we put
|
|
// in place, so we use a hand-written iterator.
|
|
//
|
|
// [restrictions]: https://github.com/rust-lang/rust/issues/34511#issuecomment-373423999
|
|
AssociatedItemsIterator {
|
|
tcx: self,
|
|
def_ids: self.associated_item_def_ids(def_id),
|
|
next_index: 0,
|
|
}
|
|
}
|
|
|
|
/// Returns `true` if the impls are the same polarity and the trait either
|
|
/// has no items or is annotated #[marker] and prevents item overrides.
|
|
pub fn impls_are_allowed_to_overlap(self, def_id1: DefId, def_id2: DefId) -> bool {
|
|
if self.features().overlapping_marker_traits {
|
|
let trait1_is_empty = self.impl_trait_ref(def_id1)
|
|
.map_or(false, |trait_ref| {
|
|
self.associated_item_def_ids(trait_ref.def_id).is_empty()
|
|
});
|
|
let trait2_is_empty = self.impl_trait_ref(def_id2)
|
|
.map_or(false, |trait_ref| {
|
|
self.associated_item_def_ids(trait_ref.def_id).is_empty()
|
|
});
|
|
self.impl_polarity(def_id1) == self.impl_polarity(def_id2)
|
|
&& trait1_is_empty
|
|
&& trait2_is_empty
|
|
} else if self.features().marker_trait_attr {
|
|
let is_marker_impl = |def_id: DefId| -> bool {
|
|
let trait_ref = self.impl_trait_ref(def_id);
|
|
trait_ref.map_or(false, |tr| self.trait_def(tr.def_id).is_marker)
|
|
};
|
|
self.impl_polarity(def_id1) == self.impl_polarity(def_id2)
|
|
&& is_marker_impl(def_id1)
|
|
&& is_marker_impl(def_id2)
|
|
} else {
|
|
false
|
|
}
|
|
}
|
|
|
|
// Returns `ty::VariantDef` if `def` refers to a struct,
|
|
// or variant or their constructors, panics otherwise.
|
|
pub fn expect_variant_def(self, def: Def) -> &'tcx VariantDef {
|
|
match def {
|
|
Def::Variant(did) | Def::VariantCtor(did, ..) => {
|
|
let enum_did = self.parent_def_id(did).unwrap();
|
|
self.adt_def(enum_did).variant_with_id(did)
|
|
}
|
|
Def::Struct(did) | Def::Union(did) => {
|
|
self.adt_def(did).non_enum_variant()
|
|
}
|
|
Def::StructCtor(ctor_did, ..) => {
|
|
let did = self.parent_def_id(ctor_did).expect("struct ctor has no parent");
|
|
self.adt_def(did).non_enum_variant()
|
|
}
|
|
_ => bug!("expect_variant_def used with unexpected def {:?}", def)
|
|
}
|
|
}
|
|
|
|
/// Given a `VariantDef`, returns the def-id of the `AdtDef` of which it is a part.
|
|
pub fn adt_def_id_of_variant(self, variant_def: &'tcx VariantDef) -> DefId {
|
|
let def_key = self.def_key(variant_def.did);
|
|
match def_key.disambiguated_data.data {
|
|
// for enum variants and tuple structs, the def-id of the ADT itself
|
|
// is the *parent* of the variant
|
|
DefPathData::EnumVariant(..) | DefPathData::StructCtor =>
|
|
DefId { krate: variant_def.did.krate, index: def_key.parent.unwrap() },
|
|
|
|
// otherwise, for structs and unions, they share a def-id
|
|
_ => variant_def.did,
|
|
}
|
|
}
|
|
|
|
pub fn item_name(self, id: DefId) -> InternedString {
|
|
if id.index == CRATE_DEF_INDEX {
|
|
self.original_crate_name(id.krate).as_interned_str()
|
|
} else {
|
|
let def_key = self.def_key(id);
|
|
// The name of a StructCtor is that of its struct parent.
|
|
if let hir_map::DefPathData::StructCtor = def_key.disambiguated_data.data {
|
|
self.item_name(DefId {
|
|
krate: id.krate,
|
|
index: def_key.parent.unwrap()
|
|
})
|
|
} else {
|
|
def_key.disambiguated_data.data.get_opt_name().unwrap_or_else(|| {
|
|
bug!("item_name: no name for {:?}", self.def_path(id));
|
|
})
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Return the possibly-auto-generated MIR of a (DefId, Subst) pair.
|
|
pub fn instance_mir(self, instance: ty::InstanceDef<'gcx>)
|
|
-> &'gcx Mir<'gcx>
|
|
{
|
|
match instance {
|
|
ty::InstanceDef::Item(did) => {
|
|
self.optimized_mir(did)
|
|
}
|
|
ty::InstanceDef::VtableShim(..) |
|
|
ty::InstanceDef::Intrinsic(..) |
|
|
ty::InstanceDef::FnPtrShim(..) |
|
|
ty::InstanceDef::Virtual(..) |
|
|
ty::InstanceDef::ClosureOnceShim { .. } |
|
|
ty::InstanceDef::DropGlue(..) |
|
|
ty::InstanceDef::CloneShim(..) => {
|
|
self.mir_shims(instance)
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Given the DefId of an item, returns its MIR, borrowed immutably.
|
|
/// Returns None if there is no MIR for the DefId
|
|
pub fn maybe_optimized_mir(self, did: DefId) -> Option<&'gcx Mir<'gcx>> {
|
|
if self.is_mir_available(did) {
|
|
Some(self.optimized_mir(did))
|
|
} else {
|
|
None
|
|
}
|
|
}
|
|
|
|
/// Get the attributes of a definition.
|
|
pub fn get_attrs(self, did: DefId) -> Attributes<'gcx> {
|
|
if let Some(id) = self.hir.as_local_node_id(did) {
|
|
Attributes::Borrowed(self.hir.attrs(id))
|
|
} else {
|
|
Attributes::Owned(self.item_attrs(did))
|
|
}
|
|
}
|
|
|
|
/// Determine whether an item is annotated with an attribute.
|
|
pub fn has_attr(self, did: DefId, attr: &str) -> bool {
|
|
attr::contains_name(&self.get_attrs(did), attr)
|
|
}
|
|
|
|
/// 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
|
|
}
|
|
|
|
pub fn generator_layout(self, def_id: DefId) -> &'tcx GeneratorLayout<'tcx> {
|
|
self.optimized_mir(def_id).generator_layout.as_ref().unwrap()
|
|
}
|
|
|
|
/// Given the def-id of an impl, return the def_id of the trait it implements.
|
|
/// If it implements no trait, return `None`.
|
|
pub fn trait_id_of_impl(self, def_id: DefId) -> Option<DefId> {
|
|
self.impl_trait_ref(def_id).map(|tr| tr.def_id)
|
|
}
|
|
|
|
/// If the given defid describes a method belonging to an impl, return the
|
|
/// def-id of the impl that the method belongs to. Otherwise, return `None`.
|
|
pub fn impl_of_method(self, def_id: DefId) -> Option<DefId> {
|
|
let item = if def_id.krate != LOCAL_CRATE {
|
|
if let Some(Def::Method(_)) = self.describe_def(def_id) {
|
|
Some(self.associated_item(def_id))
|
|
} else {
|
|
None
|
|
}
|
|
} else {
|
|
self.opt_associated_item(def_id)
|
|
};
|
|
|
|
item.and_then(|trait_item|
|
|
match trait_item.container {
|
|
TraitContainer(_) => None,
|
|
ImplContainer(def_id) => Some(def_id),
|
|
}
|
|
)
|
|
}
|
|
|
|
/// 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_did: DefId) -> Result<Span, Symbol> {
|
|
if impl_did.is_local() {
|
|
let node_id = self.hir.as_local_node_id(impl_did).unwrap();
|
|
Ok(self.hir.span(node_id))
|
|
} else {
|
|
Err(self.crate_name(impl_did.krate))
|
|
}
|
|
}
|
|
|
|
// Hygienically compare 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_name: Ident, def_name: Ident, def_parent_def_id: DefId) -> bool {
|
|
self.adjust_ident(use_name, def_parent_def_id, DUMMY_NODE_ID).0 == def_name.modern()
|
|
}
|
|
|
|
pub fn adjust_ident(self, mut ident: Ident, scope: DefId, block: NodeId) -> (Ident, DefId) {
|
|
ident = ident.modern();
|
|
let target_expansion = match scope.krate {
|
|
LOCAL_CRATE => self.hir.definitions().expansion_that_defined(scope.index),
|
|
_ => Mark::root(),
|
|
};
|
|
let scope = match ident.span.adjust(target_expansion) {
|
|
Some(actual_expansion) =>
|
|
self.hir.definitions().parent_module_of_macro_def(actual_expansion),
|
|
None if block == DUMMY_NODE_ID => DefId::local(CRATE_DEF_INDEX), // Dummy DefId
|
|
None => self.hir.get_module_parent(block),
|
|
};
|
|
(ident, scope)
|
|
}
|
|
}
|
|
|
|
pub struct AssociatedItemsIterator<'a, 'gcx: 'tcx, 'tcx: 'a> {
|
|
tcx: TyCtxt<'a, 'gcx, 'tcx>,
|
|
def_ids: Lrc<Vec<DefId>>,
|
|
next_index: usize,
|
|
}
|
|
|
|
impl Iterator for AssociatedItemsIterator<'_, '_, '_> {
|
|
type Item = AssociatedItem;
|
|
|
|
fn next(&mut self) -> Option<AssociatedItem> {
|
|
let def_id = self.def_ids.get(self.next_index)?;
|
|
self.next_index += 1;
|
|
Some(self.tcx.associated_item(*def_id))
|
|
}
|
|
}
|
|
|
|
impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
|
|
pub fn with_freevars<T, F>(self, fid: NodeId, f: F) -> T where
|
|
F: FnOnce(&[hir::Freevar]) -> T,
|
|
{
|
|
let def_id = self.hir.local_def_id(fid);
|
|
match self.freevars(def_id) {
|
|
None => f(&[]),
|
|
Some(d) => f(&d),
|
|
}
|
|
}
|
|
}
|
|
|
|
fn associated_item<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefId) -> AssociatedItem {
|
|
let id = tcx.hir.as_local_node_id(def_id).unwrap();
|
|
let parent_id = tcx.hir.get_parent(id);
|
|
let parent_def_id = tcx.hir.local_def_id(parent_id);
|
|
let parent_item = tcx.hir.expect_item(parent_id);
|
|
match parent_item.node {
|
|
hir::ItemKind::Impl(.., ref impl_item_refs) => {
|
|
if let Some(impl_item_ref) = impl_item_refs.iter().find(|i| i.id.node_id == id) {
|
|
let assoc_item = tcx.associated_item_from_impl_item_ref(parent_def_id,
|
|
impl_item_ref);
|
|
debug_assert_eq!(assoc_item.def_id, def_id);
|
|
return assoc_item;
|
|
}
|
|
}
|
|
|
|
hir::ItemKind::Trait(.., ref trait_item_refs) => {
|
|
if let Some(trait_item_ref) = trait_item_refs.iter().find(|i| i.id.node_id == id) {
|
|
let assoc_item = tcx.associated_item_from_trait_item_ref(parent_def_id,
|
|
&parent_item.vis,
|
|
trait_item_ref);
|
|
debug_assert_eq!(assoc_item.def_id, def_id);
|
|
return assoc_item;
|
|
}
|
|
}
|
|
|
|
_ => { }
|
|
}
|
|
|
|
span_bug!(parent_item.span,
|
|
"unexpected parent of trait or impl item or item not found: {:?}",
|
|
parent_item.node)
|
|
}
|
|
|
|
/// Calculates the Sized-constraint.
|
|
///
|
|
/// In fact, there are only a few options for the types in the constraint:
|
|
/// - an obviously-unsized type
|
|
/// - a type parameter or projection whose Sizedness can't be known
|
|
/// - a tuple of type parameters or projections, if there are multiple
|
|
/// such.
|
|
/// - a Error, if a type contained itself. The representability
|
|
/// check should catch this case.
|
|
fn adt_sized_constraint<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
|
|
def_id: DefId)
|
|
-> &'tcx [Ty<'tcx>] {
|
|
let def = tcx.adt_def(def_id);
|
|
|
|
let result = tcx.mk_type_list(def.variants.iter().flat_map(|v| {
|
|
v.fields.last()
|
|
}).flat_map(|f| {
|
|
def.sized_constraint_for_ty(tcx, tcx.type_of(f.did))
|
|
}));
|
|
|
|
debug!("adt_sized_constraint: {:?} => {:?}", def, result);
|
|
|
|
result
|
|
}
|
|
|
|
fn associated_item_def_ids<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
|
|
def_id: DefId)
|
|
-> Lrc<Vec<DefId>> {
|
|
let id = tcx.hir.as_local_node_id(def_id).unwrap();
|
|
let item = tcx.hir.expect_item(id);
|
|
let vec: Vec<_> = match item.node {
|
|
hir::ItemKind::Trait(.., ref trait_item_refs) => {
|
|
trait_item_refs.iter()
|
|
.map(|trait_item_ref| trait_item_ref.id)
|
|
.map(|id| tcx.hir.local_def_id(id.node_id))
|
|
.collect()
|
|
}
|
|
hir::ItemKind::Impl(.., ref impl_item_refs) => {
|
|
impl_item_refs.iter()
|
|
.map(|impl_item_ref| impl_item_ref.id)
|
|
.map(|id| tcx.hir.local_def_id(id.node_id))
|
|
.collect()
|
|
}
|
|
hir::ItemKind::TraitAlias(..) => vec![],
|
|
_ => span_bug!(item.span, "associated_item_def_ids: not impl or trait")
|
|
};
|
|
Lrc::new(vec)
|
|
}
|
|
|
|
fn def_span<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefId) -> Span {
|
|
tcx.hir.span_if_local(def_id).unwrap()
|
|
}
|
|
|
|
/// If the given def ID describes an item belonging to a trait,
|
|
/// return the ID of the trait that the trait item belongs to.
|
|
/// Otherwise, return `None`.
|
|
fn trait_of_item<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefId) -> Option<DefId> {
|
|
tcx.opt_associated_item(def_id)
|
|
.and_then(|associated_item| {
|
|
match associated_item.container {
|
|
TraitContainer(def_id) => Some(def_id),
|
|
ImplContainer(_) => None
|
|
}
|
|
})
|
|
}
|
|
|
|
/// 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(node_id) = tcx.hir.as_local_node_id(def_id) {
|
|
if let Node::Item(item) = tcx.hir.get(node_id) {
|
|
if let hir::ItemKind::Existential(ref exist_ty) = item.node {
|
|
return exist_ty.impl_trait_fn;
|
|
}
|
|
}
|
|
}
|
|
None
|
|
}
|
|
|
|
/// Returns `true` if `def_id` is a trait alias.
|
|
pub fn is_trait_alias(tcx: TyCtxt<'_, '_, '_>, def_id: DefId) -> bool {
|
|
if let Some(node_id) = tcx.hir.as_local_node_id(def_id) {
|
|
if let Node::Item(item) = tcx.hir.get(node_id) {
|
|
if let hir::ItemKind::TraitAlias(..) = item.node {
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
false
|
|
}
|
|
|
|
/// See `ParamEnv` struct definition for details.
|
|
fn param_env<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
|
|
def_id: DefId)
|
|
-> ParamEnv<'tcx>
|
|
{
|
|
// The param_env of an impl Trait type is its defining function's param_env
|
|
if let Some(parent) = is_impl_trait_defn(tcx, def_id) {
|
|
return param_env(tcx, parent);
|
|
}
|
|
// Compute the bounds on Self and the type parameters.
|
|
|
|
let InstantiatedPredicates { predicates } =
|
|
tcx.predicates_of(def_id).instantiate_identity(tcx);
|
|
|
|
// Finally, we have to normalize the bounds in the environment, in
|
|
// case they contain any associated type projections. This process
|
|
// can yield errors if the put in illegal associated types, like
|
|
// `<i32 as Foo>::Bar` where `i32` does not implement `Foo`. We
|
|
// report these errors right here; this doesn't actually feel
|
|
// right to me, because constructing the environment feels like a
|
|
// kind of a "idempotent" action, but I'm not sure where would be
|
|
// a better place. In practice, we construct environments for
|
|
// every fn once during type checking, and we'll abort if there
|
|
// are any errors at that point, so after type checking you can be
|
|
// sure that this will succeed without errors anyway.
|
|
|
|
let unnormalized_env = ty::ParamEnv::new(tcx.intern_predicates(&predicates),
|
|
traits::Reveal::UserFacing);
|
|
|
|
let body_id = tcx.hir.as_local_node_id(def_id).map_or(DUMMY_NODE_ID, |id| {
|
|
tcx.hir.maybe_body_owned_by(id).map_or(id, |body| body.node_id)
|
|
});
|
|
let cause = traits::ObligationCause::misc(tcx.def_span(def_id), body_id);
|
|
traits::normalize_param_env_or_error(tcx, def_id, unnormalized_env, cause)
|
|
}
|
|
|
|
fn crate_disambiguator<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
|
|
crate_num: CrateNum) -> CrateDisambiguator {
|
|
assert_eq!(crate_num, LOCAL_CRATE);
|
|
tcx.sess.local_crate_disambiguator()
|
|
}
|
|
|
|
fn original_crate_name<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
|
|
crate_num: CrateNum) -> Symbol {
|
|
assert_eq!(crate_num, LOCAL_CRATE);
|
|
tcx.crate_name.clone()
|
|
}
|
|
|
|
fn crate_hash<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
|
|
crate_num: CrateNum)
|
|
-> Svh {
|
|
assert_eq!(crate_num, LOCAL_CRATE);
|
|
tcx.hir.crate_hash
|
|
}
|
|
|
|
fn instance_def_size_estimate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
|
|
instance_def: InstanceDef<'tcx>)
|
|
-> usize {
|
|
match instance_def {
|
|
InstanceDef::Item(..) |
|
|
InstanceDef::DropGlue(..) => {
|
|
let mir = tcx.instance_mir(instance_def);
|
|
mir.basic_blocks().iter().map(|bb| bb.statements.len()).sum()
|
|
},
|
|
// Estimate the size of other compiler-generated shims to be 1.
|
|
_ => 1
|
|
}
|
|
}
|
|
|
|
pub fn provide(providers: &mut ty::query::Providers<'_>) {
|
|
context::provide(providers);
|
|
erase_regions::provide(providers);
|
|
layout::provide(providers);
|
|
util::provide(providers);
|
|
constness::provide(providers);
|
|
*providers = ty::query::Providers {
|
|
associated_item,
|
|
associated_item_def_ids,
|
|
adt_sized_constraint,
|
|
def_span,
|
|
param_env,
|
|
trait_of_item,
|
|
crate_disambiguator,
|
|
original_crate_name,
|
|
crate_hash,
|
|
trait_impls_of: trait_def::trait_impls_of_provider,
|
|
instance_def_size_estimate,
|
|
..*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)]
|
|
pub struct CrateInherentImpls {
|
|
pub inherent_impls: DefIdMap<Lrc<Vec<DefId>>>,
|
|
}
|
|
|
|
#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, RustcEncodable, RustcDecodable)]
|
|
pub struct SymbolName {
|
|
// FIXME: we don't rely on interning or equality here - better have
|
|
// this be a `&'tcx str`.
|
|
pub name: InternedString
|
|
}
|
|
|
|
impl_stable_hash_for!(struct self::SymbolName {
|
|
name
|
|
});
|
|
|
|
impl SymbolName {
|
|
pub fn new(name: &str) -> SymbolName {
|
|
SymbolName {
|
|
name: Symbol::intern(name).as_interned_str()
|
|
}
|
|
}
|
|
|
|
pub fn as_str(&self) -> LocalInternedString {
|
|
self.name.as_str()
|
|
}
|
|
}
|
|
|
|
impl fmt::Display for SymbolName {
|
|
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
|
|
fmt::Display::fmt(&self.name, fmt)
|
|
}
|
|
}
|
|
|
|
impl fmt::Debug for SymbolName {
|
|
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
|
|
fmt::Display::fmt(&self.name, fmt)
|
|
}
|
|
}
|