2939 lines
108 KiB
Rust
2939 lines
108 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::DtorKind::*;
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pub use self::ImplOrTraitItemContainer::*;
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pub use self::BorrowKind::*;
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pub use self::ImplOrTraitItem::*;
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pub use self::IntVarValue::*;
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pub use self::LvaluePreference::*;
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pub use self::fold::TypeFoldable;
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use dep_graph::{self, DepNode};
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use hir::map as ast_map;
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use middle;
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use hir::def::{Def, CtorKind, PathResolution, ExportMap};
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use hir::def_id::{CrateNum, DefId, CRATE_DEF_INDEX, LOCAL_CRATE};
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use middle::lang_items::{FnTraitLangItem, FnMutTraitLangItem, FnOnceTraitLangItem};
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use middle::region::{CodeExtent, ROOT_CODE_EXTENT};
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use traits;
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use ty;
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use ty::subst::{Subst, Substs};
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use ty::walk::TypeWalker;
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use util::common::MemoizationMap;
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use util::nodemap::NodeSet;
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use util::nodemap::FnvHashMap;
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use serialize::{self, Encodable, Encoder};
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use std::borrow::Cow;
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use std::cell::{Cell, RefCell};
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use std::hash::{Hash, Hasher};
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use std::iter;
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use std::ops::Deref;
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use std::rc::Rc;
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use std::slice;
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use std::vec::IntoIter;
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use syntax::ast::{self, Name, NodeId};
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use syntax::attr;
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use syntax::parse::token::{self, InternedString};
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use syntax_pos::{DUMMY_SP, Span};
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use rustc_const_math::ConstInt;
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use hir;
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use hir::intravisit::Visitor;
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pub use self::sty::{Binder, DebruijnIndex};
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pub use self::sty::{BuiltinBound, BuiltinBounds};
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pub use self::sty::{BareFnTy, FnSig, PolyFnSig};
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pub use self::sty::{ClosureTy, InferTy, ParamTy, ProjectionTy, TraitObject};
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pub use self::sty::{ClosureSubsts, TypeAndMut};
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pub use self::sty::{TraitRef, TypeVariants, PolyTraitRef};
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pub use self::sty::{ExistentialTraitRef, PolyExistentialTraitRef};
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pub use self::sty::{ExistentialProjection, PolyExistentialProjection};
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pub use self::sty::{BoundRegion, EarlyBoundRegion, FreeRegion, Region};
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pub use self::sty::Issue32330;
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pub use self::sty::{TyVid, IntVid, FloatVid, RegionVid, SkolemizedRegionVid};
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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::Region::*;
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pub use self::sty::TypeVariants::*;
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pub use self::sty::BuiltinBound::Send as BoundSend;
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pub use self::sty::BuiltinBound::Sized as BoundSized;
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pub use self::sty::BuiltinBound::Copy as BoundCopy;
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pub use self::sty::BuiltinBound::Sync as BoundSync;
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pub use self::contents::TypeContents;
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pub use self::context::{TyCtxt, tls};
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pub use self::context::{CtxtArenas, Lift, Tables};
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pub use self::trait_def::{TraitDef, TraitFlags};
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pub mod adjustment;
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pub mod cast;
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pub mod error;
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pub mod fast_reject;
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pub mod fold;
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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 maps;
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pub mod outlives;
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pub mod relate;
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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 contents;
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mod context;
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mod flags;
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mod ivar;
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mod structural_impls;
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mod sty;
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pub type Disr = ConstInt;
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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 trans and later passes.
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#[derive(Clone)]
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pub struct CrateAnalysis<'a> {
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pub export_map: ExportMap,
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pub access_levels: middle::privacy::AccessLevels,
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pub reachable: NodeSet,
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pub name: &'a str,
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pub glob_map: Option<hir::GlobMap>,
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}
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#[derive(Copy, Clone)]
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pub enum DtorKind {
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NoDtor,
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TraitDtor
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}
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impl DtorKind {
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pub fn is_present(&self) -> bool {
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match *self {
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TraitDtor => true,
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_ => false
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}
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}
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}
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#[derive(Clone, Copy, PartialEq, Eq, Debug)]
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pub enum ImplOrTraitItemContainer {
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TraitContainer(DefId),
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ImplContainer(DefId),
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}
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impl ImplOrTraitItemContainer {
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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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impl<'a, 'gcx, 'tcx> ImplHeader<'tcx> {
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pub fn with_fresh_ty_vars(selcx: &mut traits::SelectionContext<'a, 'gcx, 'tcx>,
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impl_def_id: DefId)
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-> ImplHeader<'tcx>
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{
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let tcx = selcx.tcx();
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let impl_substs = selcx.infcx().fresh_substs_for_item(DUMMY_SP, impl_def_id);
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let header = ImplHeader {
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impl_def_id: impl_def_id,
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self_ty: tcx.lookup_item_type(impl_def_id).ty,
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trait_ref: tcx.impl_trait_ref(impl_def_id),
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predicates: tcx.lookup_predicates(impl_def_id).predicates
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}.subst(tcx, impl_substs);
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let traits::Normalized { value: mut header, obligations } =
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traits::normalize(selcx, traits::ObligationCause::dummy(), &header);
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header.predicates.extend(obligations.into_iter().map(|o| o.predicate));
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header
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}
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}
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#[derive(Clone)]
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pub enum ImplOrTraitItem<'tcx> {
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ConstTraitItem(Rc<AssociatedConst<'tcx>>),
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MethodTraitItem(Rc<Method<'tcx>>),
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TypeTraitItem(Rc<AssociatedType<'tcx>>),
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}
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impl<'tcx> ImplOrTraitItem<'tcx> {
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pub fn def(&self) -> Def {
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match *self {
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ConstTraitItem(ref associated_const) => Def::AssociatedConst(associated_const.def_id),
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MethodTraitItem(ref method) => Def::Method(method.def_id),
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TypeTraitItem(ref ty) => Def::AssociatedTy(ty.def_id),
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}
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}
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pub fn def_id(&self) -> DefId {
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match *self {
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ConstTraitItem(ref associated_const) => associated_const.def_id,
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MethodTraitItem(ref method) => method.def_id,
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TypeTraitItem(ref associated_type) => associated_type.def_id,
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}
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}
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pub fn name(&self) -> Name {
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match *self {
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ConstTraitItem(ref associated_const) => associated_const.name,
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MethodTraitItem(ref method) => method.name,
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TypeTraitItem(ref associated_type) => associated_type.name,
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}
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}
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pub fn vis(&self) -> Visibility {
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match *self {
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ConstTraitItem(ref associated_const) => associated_const.vis,
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MethodTraitItem(ref method) => method.vis,
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TypeTraitItem(ref associated_type) => associated_type.vis,
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}
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}
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pub fn container(&self) -> ImplOrTraitItemContainer {
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match *self {
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ConstTraitItem(ref associated_const) => associated_const.container,
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MethodTraitItem(ref method) => method.container,
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TypeTraitItem(ref associated_type) => associated_type.container,
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}
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}
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pub fn as_opt_method(&self) -> Option<Rc<Method<'tcx>>> {
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match *self {
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MethodTraitItem(ref m) => Some((*m).clone()),
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_ => None,
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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(NodeId),
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/// Not visible anywhere in the local crate. This is the visibility of private external items.
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PrivateExternal,
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}
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pub trait NodeIdTree {
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fn is_descendant_of(&self, node: NodeId, ancestor: NodeId) -> bool;
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}
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impl<'a> NodeIdTree for ast_map::Map<'a> {
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fn is_descendant_of(&self, node: NodeId, ancestor: NodeId) -> bool {
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let mut node_ancestor = node;
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while node_ancestor != ancestor {
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let node_ancestor_parent = self.get_module_parent(node_ancestor);
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if node_ancestor_parent == node_ancestor {
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return false;
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}
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node_ancestor = node_ancestor_parent;
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}
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true
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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 {
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hir::Public => Visibility::Public,
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hir::Visibility::Crate => Visibility::Restricted(ast::CRATE_NODE_ID),
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hir::Visibility::Restricted { id, .. } => match tcx.expect_def(id) {
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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(tcx.map.as_local_node_id(def.def_id()).unwrap()),
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},
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hir::Inherited => Visibility::Restricted(tcx.map.get_module_parent(id)),
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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: NodeIdTree>(self, block: NodeId, 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::PrivateExternal => return false,
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// Restricted items are visible in an arbitrary local module.
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Visibility::Restricted(module) => module,
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};
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tree.is_descendant_of(block, 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: NodeIdTree>(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::PrivateExternal => 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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}
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#[derive(Clone, Debug)]
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pub struct Method<'tcx> {
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pub name: Name,
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pub generics: &'tcx Generics<'tcx>,
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pub predicates: GenericPredicates<'tcx>,
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pub fty: &'tcx BareFnTy<'tcx>,
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pub explicit_self: ExplicitSelfCategory<'tcx>,
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pub vis: Visibility,
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pub defaultness: hir::Defaultness,
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pub has_body: bool,
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pub def_id: DefId,
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pub container: ImplOrTraitItemContainer,
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}
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impl<'tcx> Method<'tcx> {
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pub fn container_id(&self) -> DefId {
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match self.container {
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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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impl<'tcx> PartialEq for Method<'tcx> {
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#[inline]
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fn eq(&self, other: &Self) -> bool { self.def_id == other.def_id }
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}
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impl<'tcx> Eq for Method<'tcx> {}
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impl<'tcx> Hash for Method<'tcx> {
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#[inline]
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fn hash<H: Hasher>(&self, s: &mut H) {
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self.def_id.hash(s)
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}
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}
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#[derive(Clone, Copy, Debug)]
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pub struct AssociatedConst<'tcx> {
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pub name: Name,
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pub ty: Ty<'tcx>,
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pub vis: Visibility,
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pub defaultness: hir::Defaultness,
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pub def_id: DefId,
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pub container: ImplOrTraitItemContainer,
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pub has_value: bool
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}
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#[derive(Clone, Copy, Debug)]
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pub struct AssociatedType<'tcx> {
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pub name: Name,
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pub ty: Option<Ty<'tcx>>,
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pub vis: Visibility,
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pub defaultness: hir::Defaultness,
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pub def_id: DefId,
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pub container: ImplOrTraitItemContainer,
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}
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#[derive(Clone, PartialEq, RustcDecodable, RustcEncodable, Copy)]
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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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#[derive(Clone, Copy, Debug, RustcDecodable, RustcEncodable)]
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pub struct MethodCallee<'tcx> {
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/// Impl method ID, for inherent methods, or trait method ID, otherwise.
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pub def_id: DefId,
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pub ty: Ty<'tcx>,
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pub substs: &'tcx Substs<'tcx>
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}
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/// With method calls, we store some extra information in
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/// side tables (i.e method_map). We use
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/// MethodCall as a key to index into these tables instead of
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/// just directly using the expression's NodeId. The reason
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/// for this being that we may apply adjustments (coercions)
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/// with the resulting expression also needing to use the
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/// side tables. The problem with this is that we don't
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/// assign a separate NodeId to this new expression
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/// and so it would clash with the base expression if both
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/// needed to add to the side tables. Thus to disambiguate
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/// we also keep track of whether there's an adjustment in
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/// our key.
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#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
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pub struct MethodCall {
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pub expr_id: NodeId,
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pub autoderef: u32
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}
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impl MethodCall {
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pub fn expr(id: NodeId) -> MethodCall {
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MethodCall {
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expr_id: id,
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autoderef: 0
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}
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}
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pub fn autoderef(expr_id: NodeId, autoderef: u32) -> MethodCall {
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MethodCall {
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expr_id: expr_id,
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autoderef: 1 + autoderef
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}
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}
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}
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// maps from an expression id that corresponds to a method call to the details
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// of the method to be invoked
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pub type MethodMap<'tcx> = FnvHashMap<MethodCall, MethodCallee<'tcx>>;
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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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/// Describes the fragment-state associated with a NodeId.
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///
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/// Currently only unfragmented paths have entries in the table,
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/// but longer-term this enum is expected to expand to also
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/// include data for fragmented paths.
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#[derive(Copy, Clone, Debug)]
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pub enum FragmentInfo {
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Moved { var: NodeId, move_expr: NodeId },
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Assigned { var: NodeId, assign_expr: NodeId, assignee_id: NodeId },
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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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flags 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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const HAS_RE_EARLY_BOUND = 1 << 5,
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const HAS_FREE_REGIONS = 1 << 6,
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const HAS_TY_ERR = 1 << 7,
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const HAS_PROJECTION = 1 << 8,
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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_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 TyInfer 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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const NEEDS_SUBST = TypeFlags::HAS_PARAMS.bits |
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TypeFlags::HAS_SELF.bits |
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TypeFlags::HAS_RE_EARLY_BOUND.bits,
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// Flags representing the nominal content of a type,
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// computed by FlagsComputation. If you add a new nominal
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// flag, it should be added here too.
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const NOMINAL_FLAGS = TypeFlags::HAS_PARAMS.bits |
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TypeFlags::HAS_SELF.bits |
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TypeFlags::HAS_TY_INFER.bits |
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TypeFlags::HAS_RE_INFER.bits |
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TypeFlags::HAS_RE_SKOL.bits |
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TypeFlags::HAS_RE_EARLY_BOUND.bits |
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TypeFlags::HAS_FREE_REGIONS.bits |
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TypeFlags::HAS_TY_ERR.bits |
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TypeFlags::HAS_PROJECTION.bits |
|
|
TypeFlags::HAS_TY_CLOSURE.bits |
|
|
TypeFlags::HAS_LOCAL_NAMES.bits |
|
|
TypeFlags::KEEP_IN_LOCAL_TCX.bits,
|
|
|
|
// Caches for type_is_sized, type_moves_by_default
|
|
const SIZEDNESS_CACHED = 1 << 16,
|
|
const IS_SIZED = 1 << 17,
|
|
const MOVENESS_CACHED = 1 << 18,
|
|
const MOVES_BY_DEFAULT = 1 << 19,
|
|
}
|
|
}
|
|
|
|
pub struct TyS<'tcx> {
|
|
pub sty: TypeVariants<'tcx>,
|
|
pub flags: Cell<TypeFlags>,
|
|
|
|
// the maximal depth of any bound regions appearing in this type.
|
|
region_depth: u32,
|
|
}
|
|
|
|
impl<'tcx> PartialEq for TyS<'tcx> {
|
|
#[inline]
|
|
fn eq(&self, other: &TyS<'tcx>) -> bool {
|
|
// (self as *const _) == (other as *const _)
|
|
(self as *const TyS<'tcx>) == (other as *const TyS<'tcx>)
|
|
}
|
|
}
|
|
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)
|
|
}
|
|
}
|
|
|
|
pub type Ty<'tcx> = &'tcx TyS<'tcx>;
|
|
|
|
impl<'tcx> serialize::UseSpecializedEncodable for Ty<'tcx> {}
|
|
impl<'tcx> serialize::UseSpecializedDecodable for Ty<'tcx> {}
|
|
|
|
/// 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 + length for both
|
|
/// equality comparisons and hashing.
|
|
#[derive(Debug, RustcEncodable)]
|
|
pub struct Slice<T>([T]);
|
|
|
|
impl<T> PartialEq for Slice<T> {
|
|
#[inline]
|
|
fn eq(&self, other: &Slice<T>) -> bool {
|
|
(&self.0 as *const [T]) == (&other.0 as *const [T])
|
|
}
|
|
}
|
|
impl<T> Eq for Slice<T> {}
|
|
|
|
impl<T> Hash for Slice<T> {
|
|
fn hash<H: Hasher>(&self, s: &mut H) {
|
|
(self.as_ptr(), self.len()).hash(s)
|
|
}
|
|
}
|
|
|
|
impl<T> Deref for Slice<T> {
|
|
type Target = [T];
|
|
fn deref(&self) -> &[T] {
|
|
&self.0
|
|
}
|
|
}
|
|
|
|
impl<'a, T> IntoIterator for &'a Slice<T> {
|
|
type Item = &'a T;
|
|
type IntoIter = <&'a [T] as IntoIterator>::IntoIter;
|
|
fn into_iter(self) -> Self::IntoIter {
|
|
self[..].iter()
|
|
}
|
|
}
|
|
|
|
impl<'tcx> serialize::UseSpecializedDecodable for &'tcx Slice<Ty<'tcx>> {}
|
|
|
|
/// 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)]
|
|
pub struct UpvarId {
|
|
pub var_id: NodeId,
|
|
pub closure_expr_id: NodeId,
|
|
}
|
|
|
|
#[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 you 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: &'tcx ty::Region,
|
|
}
|
|
|
|
pub type UpvarCaptureMap<'tcx> = FnvHashMap<UpvarId, UpvarCapture<'tcx>>;
|
|
|
|
#[derive(Copy, Clone)]
|
|
pub struct ClosureUpvar<'tcx> {
|
|
pub def: Def,
|
|
pub span: Span,
|
|
pub ty: Ty<'tcx>,
|
|
}
|
|
|
|
#[derive(Clone, Copy, PartialEq)]
|
|
pub enum IntVarValue {
|
|
IntType(ast::IntTy),
|
|
UintType(ast::UintTy),
|
|
}
|
|
|
|
/// Default region to use for the bound of objects that are
|
|
/// supplied as the value for this type parameter. This is derived
|
|
/// from `T:'a` annotations appearing in the type definition. If
|
|
/// this is `None`, then the default is inherited from the
|
|
/// surrounding context. See RFC #599 for details.
|
|
#[derive(Copy, Clone, RustcEncodable, RustcDecodable)]
|
|
pub enum ObjectLifetimeDefault<'tcx> {
|
|
/// Require an explicit annotation. Occurs when multiple
|
|
/// `T:'a` constraints are found.
|
|
Ambiguous,
|
|
|
|
/// Use the base default, typically 'static, but in a fn body it is a fresh variable
|
|
BaseDefault,
|
|
|
|
/// Use the given region as the default.
|
|
Specific(&'tcx Region),
|
|
}
|
|
|
|
#[derive(Clone, RustcEncodable, RustcDecodable)]
|
|
pub struct TypeParameterDef<'tcx> {
|
|
pub name: Name,
|
|
pub def_id: DefId,
|
|
pub index: u32,
|
|
pub default_def_id: DefId, // for use in error reporing about defaults
|
|
pub default: Option<Ty<'tcx>>,
|
|
pub object_lifetime_default: ObjectLifetimeDefault<'tcx>,
|
|
|
|
/// `pure_wrt_drop`, set by the (unsafe) `#[may_dangle]` attribute
|
|
/// on generic parameter `T`, asserts data behind the parameter
|
|
/// `T` won't be accessed during the parent type's `Drop` impl.
|
|
pub pure_wrt_drop: bool,
|
|
}
|
|
|
|
#[derive(Clone, RustcEncodable, RustcDecodable)]
|
|
pub struct RegionParameterDef<'tcx> {
|
|
pub name: Name,
|
|
pub def_id: DefId,
|
|
pub index: u32,
|
|
pub bounds: Vec<&'tcx ty::Region>,
|
|
|
|
/// `pure_wrt_drop`, set by the (unsafe) `#[may_dangle]` attribute
|
|
/// on generic parameter `'a`, asserts data of lifetime `'a`
|
|
/// won't be accessed during the parent type's `Drop` impl.
|
|
pub pure_wrt_drop: bool,
|
|
}
|
|
|
|
impl<'tcx> RegionParameterDef<'tcx> {
|
|
pub fn to_early_bound_region(&self) -> ty::Region {
|
|
ty::ReEarlyBound(self.to_early_bound_region_data())
|
|
}
|
|
|
|
pub fn to_early_bound_region_data(&self) -> ty::EarlyBoundRegion {
|
|
ty::EarlyBoundRegion {
|
|
index: self.index,
|
|
name: self.name,
|
|
}
|
|
}
|
|
|
|
pub fn to_bound_region(&self) -> ty::BoundRegion {
|
|
// this is an early bound region, so unaffected by #32330
|
|
ty::BoundRegion::BrNamed(self.def_id, self.name, Issue32330::WontChange)
|
|
}
|
|
}
|
|
|
|
/// Information about the formal type/lifetime parameters associated
|
|
/// with an item or method. Analogous to hir::Generics.
|
|
#[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
|
|
pub struct Generics<'tcx> {
|
|
pub parent: Option<DefId>,
|
|
pub parent_regions: u32,
|
|
pub parent_types: u32,
|
|
pub regions: Vec<RegionParameterDef<'tcx>>,
|
|
pub types: Vec<TypeParameterDef<'tcx>>,
|
|
pub has_self: bool,
|
|
}
|
|
|
|
impl<'tcx> Generics<'tcx> {
|
|
pub fn parent_count(&self) -> usize {
|
|
self.parent_regions as usize + self.parent_types as usize
|
|
}
|
|
|
|
pub fn own_count(&self) -> usize {
|
|
self.regions.len() + self.types.len()
|
|
}
|
|
|
|
pub fn count(&self) -> usize {
|
|
self.parent_count() + self.own_count()
|
|
}
|
|
|
|
pub fn region_param(&self, param: &EarlyBoundRegion) -> &RegionParameterDef<'tcx> {
|
|
&self.regions[param.index as usize - self.has_self as usize]
|
|
}
|
|
|
|
pub fn type_param(&self, param: &ParamTy) -> &TypeParameterDef<'tcx> {
|
|
&self.types[param.idx as usize - self.has_self as usize - self.regions.len()]
|
|
}
|
|
}
|
|
|
|
/// Bounds on generics.
|
|
#[derive(Clone)]
|
|
pub struct GenericPredicates<'tcx> {
|
|
pub parent: Option<DefId>,
|
|
pub predicates: Vec<Predicate<'tcx>>,
|
|
}
|
|
|
|
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.subst(tcx, substs)
|
|
}
|
|
}
|
|
|
|
fn instantiate_into(&self, tcx: TyCtxt<'a, 'gcx, 'tcx>,
|
|
instantiated: &mut InstantiatedPredicates<'tcx>,
|
|
substs: &Substs<'tcx>) {
|
|
if let Some(def_id) = self.parent {
|
|
tcx.lookup_predicates(def_id).instantiate_into(tcx, instantiated, substs);
|
|
}
|
|
instantiated.predicates.extend(self.predicates.iter().map(|p| p.subst(tcx, substs)))
|
|
}
|
|
|
|
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, 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 `T1 == T2`.
|
|
Equate(PolyEquatePredicate<'tcx>),
|
|
|
|
/// where 'a : 'b
|
|
RegionOutlives(PolyRegionOutlivesPredicate<'tcx>),
|
|
|
|
/// where T : 'a
|
|
TypeOutlives(PolyTypeOutlivesPredicate<'tcx>),
|
|
|
|
/// where <T as TraitRef>::Name == X, approximately.
|
|
/// See `ProjectionPredicate` struct for details.
|
|
Projection(PolyProjectionPredicate<'tcx>),
|
|
|
|
/// no syntax: T WF
|
|
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, ClosureKind),
|
|
}
|
|
|
|
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.0.substs;
|
|
match *self {
|
|
Predicate::Trait(ty::Binder(ref data)) =>
|
|
Predicate::Trait(ty::Binder(data.subst(tcx, substs))),
|
|
Predicate::Equate(ty::Binder(ref data)) =>
|
|
Predicate::Equate(ty::Binder(data.subst(tcx, substs))),
|
|
Predicate::RegionOutlives(ty::Binder(ref data)) =>
|
|
Predicate::RegionOutlives(ty::Binder(data.subst(tcx, substs))),
|
|
Predicate::TypeOutlives(ty::Binder(ref data)) =>
|
|
Predicate::TypeOutlives(ty::Binder(data.subst(tcx, substs))),
|
|
Predicate::Projection(ty::Binder(ref data)) =>
|
|
Predicate::Projection(ty::Binder(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, kind) =>
|
|
Predicate::ClosureKind(closure_def_id, kind),
|
|
}
|
|
}
|
|
}
|
|
|
|
#[derive(Clone, 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
|
|
}
|
|
|
|
/// Creates the dep-node for selecting/evaluating this trait reference.
|
|
fn dep_node(&self) -> DepNode<DefId> {
|
|
// Ideally, the dep-node would just have all the input types
|
|
// in it. But they are limited to including def-ids. So as an
|
|
// approximation we include the def-ids for all nominal types
|
|
// found somewhere. This means that we will e.g. conflate the
|
|
// dep-nodes for `u32: SomeTrait` and `u64: SomeTrait`, but we
|
|
// would have distinct dep-nodes for `Vec<u32>: SomeTrait`,
|
|
// `Rc<u32>: SomeTrait`, and `(Vec<u32>, Rc<u32>): SomeTrait`.
|
|
// Note that it's always sound to conflate dep-nodes, it just
|
|
// leads to more recompilation.
|
|
let def_ids: Vec<_> =
|
|
self.input_types()
|
|
.flat_map(|t| t.walk())
|
|
.filter_map(|t| match t.sty {
|
|
ty::TyAdt(adt_def, _) =>
|
|
Some(adt_def.did),
|
|
_ =>
|
|
None
|
|
})
|
|
.chain(iter::once(self.def_id()))
|
|
.collect();
|
|
DepNode::TraitSelect(def_ids)
|
|
}
|
|
|
|
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.0.def_id()
|
|
}
|
|
|
|
pub fn dep_node(&self) -> DepNode<DefId> {
|
|
// ok to skip binder since depnode does not care about regions
|
|
self.0.dep_node()
|
|
}
|
|
}
|
|
|
|
#[derive(Clone, PartialEq, Eq, Hash, Debug, RustcEncodable, RustcDecodable)]
|
|
pub struct EquatePredicate<'tcx>(pub Ty<'tcx>, pub Ty<'tcx>); // `0 == 1`
|
|
pub type PolyEquatePredicate<'tcx> = ty::Binder<EquatePredicate<'tcx>>;
|
|
|
|
#[derive(Clone, PartialEq, Eq, 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 PolyRegionOutlivesPredicate<'tcx> = PolyOutlivesPredicate<&'tcx ty::Region,
|
|
&'tcx ty::Region>;
|
|
pub type PolyTypeOutlivesPredicate<'tcx> = PolyOutlivesPredicate<Ty<'tcx>, &'tcx ty::Region>;
|
|
|
|
/// 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> {
|
|
pub fn item_name(&self) -> Name {
|
|
self.0.projection_ty.item_name // safe to skip the binder to access a name
|
|
}
|
|
}
|
|
|
|
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> {
|
|
assert!(!self.has_escaping_regions());
|
|
ty::Binder(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)
|
|
}
|
|
}
|
|
|
|
impl<'tcx> ToPolyTraitRef<'tcx> for PolyProjectionPredicate<'tcx> {
|
|
fn to_poly_trait_ref(&self) -> 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.
|
|
ty::Binder(self.0.projection_ty.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> {
|
|
// we're about to add a binder, so let's check that we don't
|
|
// accidentally capture anything, or else that might be some
|
|
// weird debruijn accounting.
|
|
assert!(!self.has_escaping_regions());
|
|
|
|
ty::Predicate::Trait(ty::Binder(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 PolyEquatePredicate<'tcx> {
|
|
fn to_predicate(&self) -> Predicate<'tcx> {
|
|
Predicate::Equate(self.clone())
|
|
}
|
|
}
|
|
|
|
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::Equate(ty::Binder(ref data)) => {
|
|
vec![data.0, data.1]
|
|
}
|
|
ty::Predicate::TypeOutlives(ty::Binder(ref data)) => {
|
|
vec![data.0]
|
|
}
|
|
ty::Predicate::RegionOutlives(..) => {
|
|
vec![]
|
|
}
|
|
ty::Predicate::Projection(ref data) => {
|
|
let trait_inputs = data.0.projection_ty.trait_ref.input_types();
|
|
trait_inputs.chain(Some(data.0.ty)).collect()
|
|
}
|
|
ty::Predicate::WellFormed(data) => {
|
|
vec![data]
|
|
}
|
|
ty::Predicate::ObjectSafe(_trait_def_id) => {
|
|
vec![]
|
|
}
|
|
ty::Predicate::ClosureKind(_closure_def_id, _kind) => {
|
|
vec![]
|
|
}
|
|
};
|
|
|
|
// 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::Equate(..) |
|
|
Predicate::RegionOutlives(..) |
|
|
Predicate::WellFormed(..) |
|
|
Predicate::ObjectSafe(..) |
|
|
Predicate::ClosureKind(..) |
|
|
Predicate::TypeOutlives(..) => {
|
|
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()
|
|
}
|
|
}
|
|
|
|
impl<'tcx> TraitRef<'tcx> {
|
|
pub fn new(def_id: DefId, substs: &'tcx Substs<'tcx>) -> TraitRef<'tcx> {
|
|
TraitRef { def_id: def_id, substs: substs }
|
|
}
|
|
|
|
pub fn self_ty(&self) -> Ty<'tcx> {
|
|
self.substs.type_at(0)
|
|
}
|
|
|
|
pub fn input_types<'a>(&'a self) -> impl DoubleEndedIterator<Item=Ty<'tcx>> + 'a {
|
|
// Select only the "input types" from a trait-reference. For
|
|
// now this is all the types that appear in the
|
|
// trait-reference, but it should eventually exclude
|
|
// associated types.
|
|
self.substs.types()
|
|
}
|
|
}
|
|
|
|
/// When type checking, we use the `ParameterEnvironment` to track
|
|
/// details about the type/lifetime parameters that are in scope.
|
|
/// It primarily stores the bounds information.
|
|
///
|
|
/// Note: This information might seem to be redundant with the data in
|
|
/// `tcx.ty_param_defs`, but it is not. That table contains the
|
|
/// parameter definitions from an "outside" perspective, but this
|
|
/// struct will contain the bounds for a parameter as seen from inside
|
|
/// the function body. Currently the only real distinction is that
|
|
/// bound lifetime parameters are replaced with free ones, but in the
|
|
/// future I hope to refine the representation of types so as to make
|
|
/// more distinctions clearer.
|
|
#[derive(Clone)]
|
|
pub struct ParameterEnvironment<'tcx> {
|
|
/// See `construct_free_substs` for details.
|
|
pub free_substs: &'tcx Substs<'tcx>,
|
|
|
|
/// Each type parameter has an implicit region bound that
|
|
/// indicates it must outlive at least the function body (the user
|
|
/// may specify stronger requirements). This field indicates the
|
|
/// region of the callee.
|
|
pub implicit_region_bound: &'tcx ty::Region,
|
|
|
|
/// 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: Vec<ty::Predicate<'tcx>>,
|
|
|
|
/// Scope that is attached to free regions for this scope. This
|
|
/// is usually the id of the fn body, but for more abstract scopes
|
|
/// like structs we often use the node-id of the struct.
|
|
///
|
|
/// FIXME(#3696). It would be nice to refactor so that free
|
|
/// regions don't have this implicit scope and instead introduce
|
|
/// relationships in the environment.
|
|
pub free_id_outlive: CodeExtent,
|
|
|
|
/// A cache for `moves_by_default`.
|
|
pub is_copy_cache: RefCell<FnvHashMap<Ty<'tcx>, bool>>,
|
|
|
|
/// A cache for `type_is_sized`
|
|
pub is_sized_cache: RefCell<FnvHashMap<Ty<'tcx>, bool>>,
|
|
}
|
|
|
|
impl<'a, 'tcx> ParameterEnvironment<'tcx> {
|
|
pub fn with_caller_bounds(&self,
|
|
caller_bounds: Vec<ty::Predicate<'tcx>>)
|
|
-> ParameterEnvironment<'tcx>
|
|
{
|
|
ParameterEnvironment {
|
|
free_substs: self.free_substs,
|
|
implicit_region_bound: self.implicit_region_bound,
|
|
caller_bounds: caller_bounds,
|
|
free_id_outlive: self.free_id_outlive,
|
|
is_copy_cache: RefCell::new(FnvHashMap()),
|
|
is_sized_cache: RefCell::new(FnvHashMap()),
|
|
}
|
|
}
|
|
|
|
/// Construct a parameter environment given an item, impl item, or trait item
|
|
pub fn for_item(tcx: TyCtxt<'a, 'tcx, 'tcx>, id: NodeId)
|
|
-> ParameterEnvironment<'tcx> {
|
|
match tcx.map.find(id) {
|
|
Some(ast_map::NodeImplItem(ref impl_item)) => {
|
|
match impl_item.node {
|
|
hir::ImplItemKind::Type(_) | hir::ImplItemKind::Const(..) => {
|
|
// associated types don't have their own entry (for some reason),
|
|
// so for now just grab environment for the impl
|
|
let impl_id = tcx.map.get_parent(id);
|
|
let impl_def_id = tcx.map.local_def_id(impl_id);
|
|
tcx.construct_parameter_environment(impl_item.span,
|
|
impl_def_id,
|
|
tcx.region_maps.item_extent(id))
|
|
}
|
|
hir::ImplItemKind::Method(_, ref body) => {
|
|
let method_def_id = tcx.map.local_def_id(id);
|
|
match tcx.impl_or_trait_item(method_def_id) {
|
|
MethodTraitItem(ref method_ty) => {
|
|
tcx.construct_parameter_environment(
|
|
impl_item.span,
|
|
method_ty.def_id,
|
|
tcx.region_maps.call_site_extent(id, body.id))
|
|
}
|
|
_ => {
|
|
bug!("ParameterEnvironment::for_item(): \
|
|
got non-method item from impl method?!")
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
Some(ast_map::NodeTraitItem(trait_item)) => {
|
|
match trait_item.node {
|
|
hir::TypeTraitItem(..) | hir::ConstTraitItem(..) => {
|
|
// associated types don't have their own entry (for some reason),
|
|
// so for now just grab environment for the trait
|
|
let trait_id = tcx.map.get_parent(id);
|
|
let trait_def_id = tcx.map.local_def_id(trait_id);
|
|
tcx.construct_parameter_environment(trait_item.span,
|
|
trait_def_id,
|
|
tcx.region_maps.item_extent(id))
|
|
}
|
|
hir::MethodTraitItem(_, ref body) => {
|
|
// Use call-site for extent (unless this is a
|
|
// trait method with no default; then fallback
|
|
// to the method id).
|
|
let method_def_id = tcx.map.local_def_id(id);
|
|
match tcx.impl_or_trait_item(method_def_id) {
|
|
MethodTraitItem(ref method_ty) => {
|
|
let extent = if let Some(ref body) = *body {
|
|
// default impl: use call_site extent as free_id_outlive bound.
|
|
tcx.region_maps.call_site_extent(id, body.id)
|
|
} else {
|
|
// no default impl: use item extent as free_id_outlive bound.
|
|
tcx.region_maps.item_extent(id)
|
|
};
|
|
tcx.construct_parameter_environment(
|
|
trait_item.span,
|
|
method_ty.def_id,
|
|
extent)
|
|
}
|
|
_ => {
|
|
bug!("ParameterEnvironment::for_item(): \
|
|
got non-method item from provided \
|
|
method?!")
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
Some(ast_map::NodeItem(item)) => {
|
|
match item.node {
|
|
hir::ItemFn(.., ref body) => {
|
|
// We assume this is a function.
|
|
let fn_def_id = tcx.map.local_def_id(id);
|
|
|
|
tcx.construct_parameter_environment(
|
|
item.span,
|
|
fn_def_id,
|
|
tcx.region_maps.call_site_extent(id, body.id))
|
|
}
|
|
hir::ItemEnum(..) |
|
|
hir::ItemStruct(..) |
|
|
hir::ItemUnion(..) |
|
|
hir::ItemTy(..) |
|
|
hir::ItemImpl(..) |
|
|
hir::ItemConst(..) |
|
|
hir::ItemStatic(..) => {
|
|
let def_id = tcx.map.local_def_id(id);
|
|
tcx.construct_parameter_environment(item.span,
|
|
def_id,
|
|
tcx.region_maps.item_extent(id))
|
|
}
|
|
hir::ItemTrait(..) => {
|
|
let def_id = tcx.map.local_def_id(id);
|
|
tcx.construct_parameter_environment(item.span,
|
|
def_id,
|
|
tcx.region_maps.item_extent(id))
|
|
}
|
|
_ => {
|
|
span_bug!(item.span,
|
|
"ParameterEnvironment::for_item():
|
|
can't create a parameter \
|
|
environment for this kind of item")
|
|
}
|
|
}
|
|
}
|
|
Some(ast_map::NodeExpr(expr)) => {
|
|
// This is a convenience to allow closures to work.
|
|
if let hir::ExprClosure(..) = expr.node {
|
|
ParameterEnvironment::for_item(tcx, tcx.map.get_parent(id))
|
|
} else {
|
|
tcx.empty_parameter_environment()
|
|
}
|
|
}
|
|
Some(ast_map::NodeForeignItem(item)) => {
|
|
let def_id = tcx.map.local_def_id(id);
|
|
tcx.construct_parameter_environment(item.span,
|
|
def_id,
|
|
ROOT_CODE_EXTENT)
|
|
}
|
|
_ => {
|
|
bug!("ParameterEnvironment::from_item(): \
|
|
`{}` is not an item",
|
|
tcx.map.node_to_string(id))
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/// A "type scheme", in ML terminology, is a type combined with some
|
|
/// set of generic types that the type is, well, generic over. In Rust
|
|
/// terms, it is the "type" of a fn item or struct -- this type will
|
|
/// include various generic parameters that must be substituted when
|
|
/// the item/struct is referenced. That is called converting the type
|
|
/// scheme to a monotype.
|
|
///
|
|
/// - `generics`: the set of type parameters and their bounds
|
|
/// - `ty`: the base types, which may reference the parameters defined
|
|
/// in `generics`
|
|
///
|
|
/// Note that TypeSchemes are also sometimes called "polytypes" (and
|
|
/// in fact this struct used to carry that name, so you may find some
|
|
/// stray references in a comment or something). We try to reserve the
|
|
/// "poly" prefix to refer to higher-ranked things, as in
|
|
/// `PolyTraitRef`.
|
|
///
|
|
/// Note that each item also comes with predicates, see
|
|
/// `lookup_predicates`.
|
|
#[derive(Clone, Debug)]
|
|
pub struct TypeScheme<'tcx> {
|
|
pub generics: &'tcx Generics<'tcx>,
|
|
pub ty: Ty<'tcx>,
|
|
}
|
|
|
|
bitflags! {
|
|
flags AdtFlags: u32 {
|
|
const NO_ADT_FLAGS = 0,
|
|
const IS_ENUM = 1 << 0,
|
|
const IS_DTORCK = 1 << 1, // is this a dtorck type?
|
|
const IS_DTORCK_VALID = 1 << 2,
|
|
const IS_PHANTOM_DATA = 1 << 3,
|
|
const IS_SIMD = 1 << 4,
|
|
const IS_FUNDAMENTAL = 1 << 5,
|
|
const IS_UNION = 1 << 6,
|
|
}
|
|
}
|
|
|
|
pub type AdtDef<'tcx> = &'tcx AdtDefData<'tcx, 'static>;
|
|
pub type VariantDef<'tcx> = &'tcx VariantDefData<'tcx, 'static>;
|
|
pub type FieldDef<'tcx> = &'tcx FieldDefData<'tcx, 'static>;
|
|
|
|
// See comment on AdtDefData for explanation
|
|
pub type AdtDefMaster<'tcx> = &'tcx AdtDefData<'tcx, 'tcx>;
|
|
pub type VariantDefMaster<'tcx> = &'tcx VariantDefData<'tcx, 'tcx>;
|
|
pub type FieldDefMaster<'tcx> = &'tcx FieldDefData<'tcx, 'tcx>;
|
|
|
|
pub struct VariantDefData<'tcx, 'container: 'tcx> {
|
|
/// 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 disr_val: Disr,
|
|
pub fields: Vec<FieldDefData<'tcx, 'container>>,
|
|
pub ctor_kind: CtorKind,
|
|
}
|
|
|
|
pub struct FieldDefData<'tcx, 'container: 'tcx> {
|
|
/// The field's DefId. NOTE: the fields of tuple-like enum variants
|
|
/// are not real items, and don't have entries in tcache etc.
|
|
pub did: DefId,
|
|
pub name: Name,
|
|
pub vis: Visibility,
|
|
/// TyIVar is used here to allow for variance (see the doc at
|
|
/// AdtDefData).
|
|
///
|
|
/// Note: direct accesses to `ty` must also add dep edges.
|
|
ty: ivar::TyIVar<'tcx, 'container>
|
|
}
|
|
|
|
/// The definition of an abstract data type - a struct or enum.
|
|
///
|
|
/// These are all interned (by intern_adt_def) into the adt_defs
|
|
/// table.
|
|
///
|
|
/// Because of the possibility of nested tcx-s, this type
|
|
/// needs 2 lifetimes: the traditional variant lifetime ('tcx)
|
|
/// bounding the lifetime of the inner types is of course necessary.
|
|
/// However, it is not sufficient - types from a child tcx must
|
|
/// not be leaked into the master tcx by being stored in an AdtDefData.
|
|
///
|
|
/// The 'container lifetime ensures that by outliving the container
|
|
/// tcx and preventing shorter-lived types from being inserted. When
|
|
/// write access is not needed, the 'container lifetime can be
|
|
/// erased to 'static, which can be done by the AdtDef wrapper.
|
|
pub struct AdtDefData<'tcx, 'container: 'tcx> {
|
|
pub did: DefId,
|
|
pub variants: Vec<VariantDefData<'tcx, 'container>>,
|
|
destructor: Cell<Option<DefId>>,
|
|
flags: Cell<AdtFlags>,
|
|
sized_constraint: ivar::TyIVar<'tcx, 'container>,
|
|
}
|
|
|
|
impl<'tcx, 'container> PartialEq for AdtDefData<'tcx, 'container> {
|
|
// AdtDefData are always interned and this is part of TyS equality
|
|
#[inline]
|
|
fn eq(&self, other: &Self) -> bool { self as *const _ == other as *const _ }
|
|
}
|
|
|
|
impl<'tcx, 'container> Eq for AdtDefData<'tcx, 'container> {}
|
|
|
|
impl<'tcx, 'container> Hash for AdtDefData<'tcx, 'container> {
|
|
#[inline]
|
|
fn hash<H: Hasher>(&self, s: &mut H) {
|
|
(self as *const AdtDefData).hash(s)
|
|
}
|
|
}
|
|
|
|
impl<'tcx> serialize::UseSpecializedEncodable for AdtDef<'tcx> {
|
|
fn default_encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
|
|
self.did.encode(s)
|
|
}
|
|
}
|
|
|
|
impl<'tcx> serialize::UseSpecializedDecodable for AdtDef<'tcx> {}
|
|
|
|
#[derive(Copy, Clone, Debug, Eq, PartialEq)]
|
|
pub enum AdtKind { Struct, Union, Enum }
|
|
|
|
impl<'a, 'gcx, 'tcx, 'container> AdtDefData<'gcx, 'container> {
|
|
fn new(tcx: TyCtxt<'a, 'gcx, 'tcx>,
|
|
did: DefId,
|
|
kind: AdtKind,
|
|
variants: Vec<VariantDefData<'gcx, 'container>>) -> Self {
|
|
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 tcx.lookup_simd(did) {
|
|
flags = flags | AdtFlags::IS_SIMD;
|
|
}
|
|
if Some(did) == tcx.lang_items.phantom_data() {
|
|
flags = flags | AdtFlags::IS_PHANTOM_DATA;
|
|
}
|
|
match kind {
|
|
AdtKind::Enum => flags = flags | AdtFlags::IS_ENUM,
|
|
AdtKind::Union => flags = flags | AdtFlags::IS_UNION,
|
|
AdtKind::Struct => {}
|
|
}
|
|
AdtDefData {
|
|
did: did,
|
|
variants: variants,
|
|
flags: Cell::new(flags),
|
|
destructor: Cell::new(None),
|
|
sized_constraint: ivar::TyIVar::new(),
|
|
}
|
|
}
|
|
|
|
fn calculate_dtorck(&'gcx self, tcx: TyCtxt) {
|
|
if tcx.is_adt_dtorck(self) {
|
|
self.flags.set(self.flags.get() | AdtFlags::IS_DTORCK);
|
|
}
|
|
self.flags.set(self.flags.get() | AdtFlags::IS_DTORCK_VALID)
|
|
}
|
|
|
|
#[inline]
|
|
pub fn is_struct(&self) -> bool {
|
|
!self.is_union() && !self.is_enum()
|
|
}
|
|
|
|
#[inline]
|
|
pub fn is_union(&self) -> bool {
|
|
self.flags.get().intersects(AdtFlags::IS_UNION)
|
|
}
|
|
|
|
#[inline]
|
|
pub fn is_enum(&self) -> bool {
|
|
self.flags.get().intersects(AdtFlags::IS_ENUM)
|
|
}
|
|
|
|
/// 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 is a dtorck type. If this returns
|
|
/// true, this type being safe for destruction requires it to be
|
|
/// alive; Otherwise, only the contents are required to be.
|
|
#[inline]
|
|
pub fn is_dtorck(&'gcx self, tcx: TyCtxt) -> bool {
|
|
if !self.flags.get().intersects(AdtFlags::IS_DTORCK_VALID) {
|
|
self.calculate_dtorck(tcx)
|
|
}
|
|
self.flags.get().intersects(AdtFlags::IS_DTORCK)
|
|
}
|
|
|
|
/// Returns whether this type is #[fundamental] for the purposes
|
|
/// of coherence checking.
|
|
#[inline]
|
|
pub fn is_fundamental(&self) -> bool {
|
|
self.flags.get().intersects(AdtFlags::IS_FUNDAMENTAL)
|
|
}
|
|
|
|
#[inline]
|
|
pub fn is_simd(&self) -> bool {
|
|
self.flags.get().intersects(AdtFlags::IS_SIMD)
|
|
}
|
|
|
|
/// Returns true if this is PhantomData<T>.
|
|
#[inline]
|
|
pub fn is_phantom_data(&self) -> bool {
|
|
self.flags.get().intersects(AdtFlags::IS_PHANTOM_DATA)
|
|
}
|
|
|
|
/// Returns whether this type has a destructor.
|
|
pub fn has_dtor(&self) -> bool {
|
|
self.dtor_kind().is_present()
|
|
}
|
|
|
|
/// Asserts this is a struct and returns the struct's unique
|
|
/// variant.
|
|
pub fn struct_variant(&self) -> &VariantDefData<'gcx, 'container> {
|
|
assert!(!self.is_enum());
|
|
&self.variants[0]
|
|
}
|
|
|
|
#[inline]
|
|
pub fn type_scheme(&self, tcx: TyCtxt<'a, 'gcx, 'tcx>) -> TypeScheme<'gcx> {
|
|
tcx.lookup_item_type(self.did)
|
|
}
|
|
|
|
#[inline]
|
|
pub fn predicates(&self, tcx: TyCtxt<'a, 'gcx, 'tcx>) -> GenericPredicates<'gcx> {
|
|
tcx.lookup_predicates(self.did)
|
|
}
|
|
|
|
/// Returns an iterator over all fields contained
|
|
/// by this ADT.
|
|
#[inline]
|
|
pub fn all_fields(&self) ->
|
|
iter::FlatMap<
|
|
slice::Iter<VariantDefData<'gcx, 'container>>,
|
|
slice::Iter<FieldDefData<'gcx, 'container>>,
|
|
for<'s> fn(&'s VariantDefData<'gcx, 'container>)
|
|
-> slice::Iter<'s, FieldDefData<'gcx, 'container>>
|
|
> {
|
|
self.variants.iter().flat_map(VariantDefData::fields_iter)
|
|
}
|
|
|
|
#[inline]
|
|
pub fn is_empty(&self) -> bool {
|
|
self.variants.is_empty()
|
|
}
|
|
|
|
#[inline]
|
|
pub fn is_univariant(&self) -> bool {
|
|
self.variants.len() == 1
|
|
}
|
|
|
|
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) -> &VariantDefData<'gcx, 'container> {
|
|
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) -> &VariantDefData<'gcx, 'container> {
|
|
match def {
|
|
Def::Variant(vid) | Def::VariantCtor(vid, ..) => self.variant_with_id(vid),
|
|
Def::Struct(..) | Def::StructCtor(..) | Def::Union(..) |
|
|
Def::TyAlias(..) | Def::AssociatedTy(..) => self.struct_variant(),
|
|
_ => bug!("unexpected def {:?} in variant_of_def", def)
|
|
}
|
|
}
|
|
|
|
pub fn destructor(&self) -> Option<DefId> {
|
|
self.destructor.get()
|
|
}
|
|
|
|
pub fn set_destructor(&self, dtor: DefId) {
|
|
self.destructor.set(Some(dtor));
|
|
}
|
|
|
|
pub fn dtor_kind(&self) -> DtorKind {
|
|
match self.destructor.get() {
|
|
Some(_) => TraitDtor,
|
|
None => NoDtor,
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'a, 'gcx, 'tcx, 'container> AdtDefData<'tcx, 'container> {
|
|
/// Returns a simpler type such that `Self: Sized` if and only
|
|
/// if that type is Sized, or `TyErr` if this type is recursive.
|
|
///
|
|
/// HACK: instead of returning a list of types, this function can
|
|
/// return a tuple. In that case, the result is Sized only if
|
|
/// all elements of the tuple are Sized.
|
|
///
|
|
/// This is generally the `struct_tail` if this is a struct, or a
|
|
/// tuple of them if this is an enum.
|
|
///
|
|
/// 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>) -> Ty<'tcx> {
|
|
match self.sized_constraint.get(DepNode::SizedConstraint(self.did)) {
|
|
None => {
|
|
let global_tcx = tcx.global_tcx();
|
|
let this = global_tcx.lookup_adt_def_master(self.did);
|
|
this.calculate_sized_constraint_inner(global_tcx, &mut Vec::new());
|
|
self.sized_constraint(tcx)
|
|
}
|
|
Some(ty) => ty
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'a, 'tcx> AdtDefData<'tcx, 'tcx> {
|
|
/// Calculates the Sized-constraint.
|
|
///
|
|
/// As the Sized-constraint of enums can be a *set* of types,
|
|
/// the Sized-constraint may need to be a set also. Because introducing
|
|
/// a new type of IVar is currently a complex affair, the Sized-constraint
|
|
/// may be a tuple.
|
|
///
|
|
/// In fact, there are only a few options for the constraint:
|
|
/// - `bool`, if the type is always Sized
|
|
/// - 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 TyError, if a type contained itself. The representability
|
|
/// check should catch this case.
|
|
fn calculate_sized_constraint_inner(&'tcx self,
|
|
tcx: TyCtxt<'a, 'tcx, 'tcx>,
|
|
stack: &mut Vec<AdtDefMaster<'tcx>>)
|
|
{
|
|
let dep_node = || DepNode::SizedConstraint(self.did);
|
|
|
|
// Follow the memoization pattern: push the computation of
|
|
// DepNode::SizedConstraint as our current task.
|
|
let _task = tcx.dep_graph.in_task(dep_node());
|
|
if self.sized_constraint.untracked_get().is_some() {
|
|
// ---------------
|
|
// can skip the dep-graph read since we just pushed the task
|
|
return;
|
|
}
|
|
|
|
if stack.contains(&self) {
|
|
debug!("calculate_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.
|
|
self.sized_constraint.fulfill(dep_node(), tcx.types.err);
|
|
return;
|
|
}
|
|
|
|
stack.push(self);
|
|
|
|
let tys : Vec<_> =
|
|
self.variants.iter().flat_map(|v| {
|
|
v.fields.last()
|
|
}).flat_map(|f| {
|
|
self.sized_constraint_for_ty(tcx, stack, f.unsubst_ty())
|
|
}).collect();
|
|
|
|
let self_ = stack.pop().unwrap();
|
|
assert_eq!(self_, self);
|
|
|
|
let ty = match tys.len() {
|
|
_ if tys.references_error() => tcx.types.err,
|
|
0 => tcx.types.bool,
|
|
1 => tys[0],
|
|
_ => tcx.mk_tup(&tys)
|
|
};
|
|
|
|
match self.sized_constraint.get(dep_node()) {
|
|
Some(old_ty) => {
|
|
debug!("calculate_sized_constraint: {:?} recurred", self);
|
|
assert_eq!(old_ty, tcx.types.err)
|
|
}
|
|
None => {
|
|
debug!("calculate_sized_constraint: {:?} => {:?}", self, ty);
|
|
self.sized_constraint.fulfill(dep_node(), ty)
|
|
}
|
|
}
|
|
}
|
|
|
|
fn sized_constraint_for_ty(
|
|
&'tcx self,
|
|
tcx: TyCtxt<'a, 'tcx, 'tcx>,
|
|
stack: &mut Vec<AdtDefMaster<'tcx>>,
|
|
ty: Ty<'tcx>
|
|
) -> Vec<Ty<'tcx>> {
|
|
let result = match ty.sty {
|
|
TyBool | TyChar | TyInt(..) | TyUint(..) | TyFloat(..) |
|
|
TyBox(..) | TyRawPtr(..) | TyRef(..) | TyFnDef(..) | TyFnPtr(_) |
|
|
TyArray(..) | TyClosure(..) | TyNever => {
|
|
vec![]
|
|
}
|
|
|
|
TyStr | TyTrait(..) | TySlice(_) | TyError => {
|
|
// these are never sized - return the target type
|
|
vec![ty]
|
|
}
|
|
|
|
TyTuple(ref tys) => {
|
|
match tys.last() {
|
|
None => vec![],
|
|
Some(ty) => self.sized_constraint_for_ty(tcx, stack, ty)
|
|
}
|
|
}
|
|
|
|
TyAdt(adt, substs) => {
|
|
// recursive case
|
|
let adt = tcx.lookup_adt_def_master(adt.did);
|
|
adt.calculate_sized_constraint_inner(tcx, stack);
|
|
let adt_ty =
|
|
adt.sized_constraint
|
|
.unwrap(DepNode::SizedConstraint(adt.did))
|
|
.subst(tcx, substs);
|
|
debug!("sized_constraint_for_ty({:?}) intermediate = {:?}",
|
|
ty, adt_ty);
|
|
if let ty::TyTuple(ref tys) = adt_ty.sty {
|
|
tys.iter().flat_map(|ty| {
|
|
self.sized_constraint_for_ty(tcx, stack, ty)
|
|
}).collect()
|
|
} else {
|
|
self.sized_constraint_for_ty(tcx, stack, adt_ty)
|
|
}
|
|
}
|
|
|
|
TyProjection(..) | TyAnon(..) => {
|
|
// must calculate explicitly.
|
|
// FIXME: consider special-casing always-Sized projections
|
|
vec![ty]
|
|
}
|
|
|
|
TyParam(..) => {
|
|
// 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(TraitRef {
|
|
def_id: sized_trait,
|
|
substs: Substs::new_trait(tcx, ty, &[])
|
|
}).to_predicate();
|
|
let predicates = tcx.lookup_predicates(self.did).predicates;
|
|
if predicates.into_iter().any(|p| p == sized_predicate) {
|
|
vec![]
|
|
} else {
|
|
vec![ty]
|
|
}
|
|
}
|
|
|
|
TyInfer(..) => {
|
|
bug!("unexpected type `{:?}` in sized_constraint_for_ty",
|
|
ty)
|
|
}
|
|
};
|
|
debug!("sized_constraint_for_ty({:?}) = {:?}", ty, result);
|
|
result
|
|
}
|
|
}
|
|
|
|
impl<'tcx, 'container> VariantDefData<'tcx, 'container> {
|
|
#[inline]
|
|
fn fields_iter(&self) -> slice::Iter<FieldDefData<'tcx, 'container>> {
|
|
self.fields.iter()
|
|
}
|
|
|
|
#[inline]
|
|
pub fn find_field_named(&self,
|
|
name: ast::Name)
|
|
-> Option<&FieldDefData<'tcx, 'container>> {
|
|
self.fields.iter().find(|f| f.name == name)
|
|
}
|
|
|
|
#[inline]
|
|
pub fn index_of_field_named(&self,
|
|
name: ast::Name)
|
|
-> Option<usize> {
|
|
self.fields.iter().position(|f| f.name == name)
|
|
}
|
|
|
|
#[inline]
|
|
pub fn field_named(&self, name: ast::Name) -> &FieldDefData<'tcx, 'container> {
|
|
self.find_field_named(name).unwrap()
|
|
}
|
|
}
|
|
|
|
impl<'a, 'gcx, 'tcx, 'container> FieldDefData<'tcx, 'container> {
|
|
pub fn new(did: DefId,
|
|
name: Name,
|
|
vis: Visibility) -> Self {
|
|
FieldDefData {
|
|
did: did,
|
|
name: name,
|
|
vis: vis,
|
|
ty: ivar::TyIVar::new()
|
|
}
|
|
}
|
|
|
|
pub fn ty(&self, tcx: TyCtxt<'a, 'gcx, 'tcx>, subst: &Substs<'tcx>) -> Ty<'tcx> {
|
|
self.unsubst_ty().subst(tcx, subst)
|
|
}
|
|
|
|
pub fn unsubst_ty(&self) -> Ty<'tcx> {
|
|
self.ty.unwrap(DepNode::FieldTy(self.did))
|
|
}
|
|
|
|
pub fn fulfill_ty(&self, ty: Ty<'container>) {
|
|
self.ty.fulfill(DepNode::FieldTy(self.did), ty);
|
|
}
|
|
}
|
|
|
|
/// Records the substitutions used to translate the polytype for an
|
|
/// item into the monotype of an item reference.
|
|
#[derive(Clone, RustcEncodable, RustcDecodable)]
|
|
pub struct ItemSubsts<'tcx> {
|
|
pub substs: &'tcx Substs<'tcx>,
|
|
}
|
|
|
|
#[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 {
|
|
pub fn trait_did(&self, tcx: TyCtxt<'a, 'tcx, 'tcx>) -> DefId {
|
|
let result = match *self {
|
|
ClosureKind::Fn => tcx.lang_items.require(FnTraitLangItem),
|
|
ClosureKind::FnMut => {
|
|
tcx.lang_items.require(FnMutTraitLangItem)
|
|
}
|
|
ClosureKind::FnOnce => {
|
|
tcx.lang_items.require(FnOnceTraitLangItem)
|
|
}
|
|
};
|
|
match result {
|
|
Ok(trait_did) => trait_did,
|
|
Err(err) => tcx.sess.fatal(&err[..]),
|
|
}
|
|
}
|
|
|
|
/// 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,
|
|
}
|
|
}
|
|
}
|
|
|
|
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) -> IntoIter<Ty<'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<'tcx> ItemSubsts<'tcx> {
|
|
pub fn is_noop(&self) -> bool {
|
|
self.substs.is_noop()
|
|
}
|
|
}
|
|
|
|
#[derive(Copy, Clone, Debug, PartialEq, Eq)]
|
|
pub enum LvaluePreference {
|
|
PreferMutLvalue,
|
|
NoPreference
|
|
}
|
|
|
|
impl LvaluePreference {
|
|
pub fn from_mutbl(m: hir::Mutability) -> Self {
|
|
match m {
|
|
hir::MutMutable => PreferMutLvalue,
|
|
hir::MutImmutable => NoPreference,
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Helper for looking things up in the various maps that are populated during
|
|
/// typeck::collect (e.g., `tcx.impl_or_trait_items`, `tcx.tcache`, etc). All of
|
|
/// these share the pattern that if the id is local, it should have been loaded
|
|
/// into the map by the `typeck::collect` phase. If the def-id is external,
|
|
/// then we have to go consult the crate loading code (and cache the result for
|
|
/// the future).
|
|
fn lookup_locally_or_in_crate_store<M, F>(descr: &str,
|
|
def_id: DefId,
|
|
map: &M,
|
|
load_external: F)
|
|
-> M::Value where
|
|
M: MemoizationMap<Key=DefId>,
|
|
F: FnOnce() -> M::Value,
|
|
{
|
|
map.memoize(def_id, || {
|
|
if def_id.is_local() {
|
|
bug!("No def'n found for {:?} in tcx.{}", def_id, descr);
|
|
}
|
|
load_external()
|
|
})
|
|
}
|
|
|
|
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",
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
|
|
pub fn node_id_to_type(self, id: NodeId) -> Ty<'gcx> {
|
|
match self.node_id_to_type_opt(id) {
|
|
Some(ty) => ty,
|
|
None => bug!("node_id_to_type: no type for node `{}`",
|
|
self.map.node_to_string(id))
|
|
}
|
|
}
|
|
|
|
pub fn node_id_to_type_opt(self, id: NodeId) -> Option<Ty<'gcx>> {
|
|
self.tables.borrow().node_types.get(&id).cloned()
|
|
}
|
|
|
|
pub fn node_id_item_substs(self, id: NodeId) -> ItemSubsts<'gcx> {
|
|
match self.tables.borrow().item_substs.get(&id) {
|
|
None => ItemSubsts {
|
|
substs: Substs::empty(self.global_tcx())
|
|
},
|
|
Some(ts) => ts.clone(),
|
|
}
|
|
}
|
|
|
|
// Returns the type of a pattern as a monotype. Like @expr_ty, this function
|
|
// doesn't provide type parameter substitutions.
|
|
pub fn pat_ty(self, pat: &hir::Pat) -> Ty<'gcx> {
|
|
self.node_id_to_type(pat.id)
|
|
}
|
|
pub fn pat_ty_opt(self, pat: &hir::Pat) -> Option<Ty<'gcx>> {
|
|
self.node_id_to_type_opt(pat.id)
|
|
}
|
|
|
|
// Returns the type of an expression as a monotype.
|
|
//
|
|
// NB (1): This is the PRE-ADJUSTMENT TYPE for the expression. That is, in
|
|
// some cases, we insert `AutoAdjustment` annotations such as auto-deref or
|
|
// auto-ref. The type returned by this function does not consider such
|
|
// adjustments. See `expr_ty_adjusted()` instead.
|
|
//
|
|
// NB (2): This type doesn't provide type parameter substitutions; e.g. if you
|
|
// ask for the type of "id" in "id(3)", it will return "fn(&isize) -> isize"
|
|
// instead of "fn(ty) -> T with T = isize".
|
|
pub fn expr_ty(self, expr: &hir::Expr) -> Ty<'gcx> {
|
|
self.node_id_to_type(expr.id)
|
|
}
|
|
|
|
pub fn expr_ty_opt(self, expr: &hir::Expr) -> Option<Ty<'gcx>> {
|
|
self.node_id_to_type_opt(expr.id)
|
|
}
|
|
|
|
/// Returns the type of `expr`, considering any `AutoAdjustment`
|
|
/// entry recorded for that expression.
|
|
///
|
|
/// It would almost certainly be better to store the adjusted ty in with
|
|
/// the `AutoAdjustment`, but I opted not to do this because it would
|
|
/// require serializing and deserializing the type and, although that's not
|
|
/// hard to do, I just hate that code so much I didn't want to touch it
|
|
/// unless it was to fix it properly, which seemed a distraction from the
|
|
/// thread at hand! -nmatsakis
|
|
pub fn expr_ty_adjusted(self, expr: &hir::Expr) -> Ty<'gcx> {
|
|
self.expr_ty(expr)
|
|
.adjust(self.global_tcx(), expr.span, expr.id,
|
|
self.tables.borrow().adjustments.get(&expr.id),
|
|
|method_call| {
|
|
self.tables.borrow().method_map.get(&method_call).map(|method| method.ty)
|
|
})
|
|
}
|
|
|
|
pub fn expr_ty_adjusted_opt(self, expr: &hir::Expr) -> Option<Ty<'gcx>> {
|
|
self.expr_ty_opt(expr).map(|t| t.adjust(self.global_tcx(),
|
|
expr.span,
|
|
expr.id,
|
|
self.tables.borrow().adjustments.get(&expr.id),
|
|
|method_call| {
|
|
self.tables.borrow().method_map.get(&method_call).map(|method| method.ty)
|
|
}))
|
|
}
|
|
|
|
pub fn expr_span(self, id: NodeId) -> Span {
|
|
match self.map.find(id) {
|
|
Some(ast_map::NodeExpr(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 local_var_name_str(self, id: NodeId) -> InternedString {
|
|
match self.map.find(id) {
|
|
Some(ast_map::NodeLocal(pat)) => {
|
|
match pat.node {
|
|
hir::PatKind::Binding(_, ref path1, _) => path1.node.as_str(),
|
|
_ => {
|
|
bug!("Variable id {} maps to {:?}, not local", id, pat);
|
|
},
|
|
}
|
|
},
|
|
r => bug!("Variable id {} maps to {:?}, not local", id, r),
|
|
}
|
|
}
|
|
|
|
pub fn expr_is_lval(self, expr: &hir::Expr) -> bool {
|
|
match expr.node {
|
|
hir::ExprPath(..) => {
|
|
// This function can be used during type checking when not all paths are
|
|
// fully resolved. Partially resolved paths in expressions can only legally
|
|
// refer to associated items which are always rvalues.
|
|
match self.expect_resolution(expr.id).base_def {
|
|
Def::Local(..) | Def::Upvar(..) | Def::Static(..) | Def::Err => true,
|
|
_ => false,
|
|
}
|
|
}
|
|
|
|
hir::ExprType(ref e, _) => {
|
|
self.expr_is_lval(e)
|
|
}
|
|
|
|
hir::ExprUnary(hir::UnDeref, _) |
|
|
hir::ExprField(..) |
|
|
hir::ExprTupField(..) |
|
|
hir::ExprIndex(..) => {
|
|
true
|
|
}
|
|
|
|
hir::ExprCall(..) |
|
|
hir::ExprMethodCall(..) |
|
|
hir::ExprStruct(..) |
|
|
hir::ExprTup(..) |
|
|
hir::ExprIf(..) |
|
|
hir::ExprMatch(..) |
|
|
hir::ExprClosure(..) |
|
|
hir::ExprBlock(..) |
|
|
hir::ExprRepeat(..) |
|
|
hir::ExprArray(..) |
|
|
hir::ExprBreak(..) |
|
|
hir::ExprAgain(..) |
|
|
hir::ExprRet(..) |
|
|
hir::ExprWhile(..) |
|
|
hir::ExprLoop(..) |
|
|
hir::ExprAssign(..) |
|
|
hir::ExprInlineAsm(..) |
|
|
hir::ExprAssignOp(..) |
|
|
hir::ExprLit(_) |
|
|
hir::ExprUnary(..) |
|
|
hir::ExprBox(..) |
|
|
hir::ExprAddrOf(..) |
|
|
hir::ExprBinary(..) |
|
|
hir::ExprCast(..) => {
|
|
false
|
|
}
|
|
}
|
|
}
|
|
|
|
pub fn provided_trait_methods(self, id: DefId) -> Vec<Rc<Method<'gcx>>> {
|
|
self.impl_or_trait_items(id).iter().filter_map(|&def_id| {
|
|
match self.impl_or_trait_item(def_id) {
|
|
MethodTraitItem(ref m) if m.has_body => Some(m.clone()),
|
|
_ => None
|
|
}
|
|
}).collect()
|
|
}
|
|
|
|
pub fn trait_impl_polarity(self, id: DefId) -> hir::ImplPolarity {
|
|
if let Some(id) = self.map.as_local_node_id(id) {
|
|
match self.map.expect_item(id).node {
|
|
hir::ItemImpl(_, polarity, ..) => polarity,
|
|
ref item => bug!("trait_impl_polarity: {:?} not an impl", item)
|
|
}
|
|
} else {
|
|
self.sess.cstore.impl_polarity(id)
|
|
}
|
|
}
|
|
|
|
pub fn custom_coerce_unsized_kind(self, did: DefId) -> adjustment::CustomCoerceUnsized {
|
|
self.custom_coerce_unsized_kinds.memoize(did, || {
|
|
let (kind, src) = if did.krate != LOCAL_CRATE {
|
|
(self.sess.cstore.custom_coerce_unsized_kind(did), "external")
|
|
} else {
|
|
(None, "local")
|
|
};
|
|
|
|
match kind {
|
|
Some(kind) => kind,
|
|
None => {
|
|
bug!("custom_coerce_unsized_kind: \
|
|
{} impl `{}` is missing its kind",
|
|
src, self.item_path_str(did));
|
|
}
|
|
}
|
|
})
|
|
}
|
|
|
|
pub fn impl_or_trait_item(self, id: DefId) -> ImplOrTraitItem<'gcx> {
|
|
lookup_locally_or_in_crate_store(
|
|
"impl_or_trait_items", id, &self.impl_or_trait_items,
|
|
|| self.sess.cstore.impl_or_trait_item(self.global_tcx(), id)
|
|
.expect("missing ImplOrTraitItem in metadata"))
|
|
}
|
|
|
|
pub fn impl_or_trait_items(self, id: DefId) -> Rc<Vec<DefId>> {
|
|
lookup_locally_or_in_crate_store(
|
|
"impl_or_trait_items", id, &self.impl_or_trait_item_def_ids,
|
|
|| Rc::new(self.sess.cstore.impl_or_trait_items(id)))
|
|
}
|
|
|
|
/// Returns the trait-ref corresponding to a given impl, or None if it is
|
|
/// an inherent impl.
|
|
pub fn impl_trait_ref(self, id: DefId) -> Option<TraitRef<'gcx>> {
|
|
lookup_locally_or_in_crate_store(
|
|
"impl_trait_refs", id, &self.impl_trait_refs,
|
|
|| self.sess.cstore.impl_trait_ref(self.global_tcx(), id))
|
|
}
|
|
|
|
/// Returns a path resolution for node id if it exists, panics otherwise.
|
|
pub fn expect_resolution(self, id: NodeId) -> PathResolution {
|
|
*self.def_map.borrow().get(&id).expect("no def-map entry for node id")
|
|
}
|
|
|
|
/// Returns a fully resolved definition for node id if it exists, panics otherwise.
|
|
pub fn expect_def(self, id: NodeId) -> Def {
|
|
self.expect_resolution(id).full_def()
|
|
}
|
|
|
|
/// Returns a fully resolved definition for node id if it exists, or none if no
|
|
/// definition exists, panics on partial resolutions to catch errors.
|
|
pub fn expect_def_or_none(self, id: NodeId) -> Option<Def> {
|
|
self.def_map.borrow().get(&id).map(|resolution| resolution.full_def())
|
|
}
|
|
|
|
// Returns `ty::VariantDef` if `def` refers to a struct,
|
|
// or variant or their constructors, panics otherwise.
|
|
pub fn expect_variant_def(self, def: Def) -> VariantDef<'tcx> {
|
|
match def {
|
|
Def::Variant(did) | Def::VariantCtor(did, ..) => {
|
|
let enum_did = self.parent_def_id(did).unwrap();
|
|
self.lookup_adt_def(enum_did).variant_with_id(did)
|
|
}
|
|
Def::Struct(did) | Def::Union(did) => {
|
|
self.lookup_adt_def(did).struct_variant()
|
|
}
|
|
Def::StructCtor(ctor_did, ..) => {
|
|
let did = self.parent_def_id(ctor_did).expect("struct ctor has no parent");
|
|
self.lookup_adt_def(did).struct_variant()
|
|
}
|
|
_ => bug!("expect_variant_def used with unexpected def {:?}", def)
|
|
}
|
|
}
|
|
|
|
pub fn def_key(self, id: DefId) -> ast_map::DefKey {
|
|
if id.is_local() {
|
|
self.map.def_key(id)
|
|
} else {
|
|
self.sess.cstore.def_key(id)
|
|
}
|
|
}
|
|
|
|
/// Convert a `DefId` into its fully expanded `DefPath` (every
|
|
/// `DefId` is really just an interned def-path).
|
|
///
|
|
/// Note that if `id` is not local to this crate -- or is
|
|
/// inlined into this crate -- the result will be a non-local
|
|
/// `DefPath`.
|
|
///
|
|
/// This function is only safe to use when you are sure that the
|
|
/// full def-path is accessible. Examples that are known to be
|
|
/// safe are local def-ids or items; see `opt_def_path` for more
|
|
/// details.
|
|
pub fn def_path(self, id: DefId) -> ast_map::DefPath {
|
|
self.opt_def_path(id).unwrap_or_else(|| {
|
|
bug!("could not load def-path for {:?}", id)
|
|
})
|
|
}
|
|
|
|
/// Convert a `DefId` into its fully expanded `DefPath` (every
|
|
/// `DefId` is really just an interned def-path).
|
|
///
|
|
/// When going across crates, we do not save the full info for
|
|
/// every cross-crate def-id, and hence we may not always be able
|
|
/// to create a def-path. Therefore, this returns
|
|
/// `Option<DefPath>` to cover that possibility. It will always
|
|
/// return `Some` for local def-ids, however, as well as for
|
|
/// items. The problems arise with "minor" def-ids like those
|
|
/// associated with a pattern, `impl Trait`, or other internal
|
|
/// detail to a fn.
|
|
///
|
|
/// Note that if `id` is not local to this crate -- or is
|
|
/// inlined into this crate -- the result will be a non-local
|
|
/// `DefPath`.
|
|
pub fn opt_def_path(self, id: DefId) -> Option<ast_map::DefPath> {
|
|
if id.is_local() {
|
|
Some(self.map.def_path(id))
|
|
} else {
|
|
self.sess.cstore.relative_def_path(id)
|
|
}
|
|
}
|
|
|
|
pub fn item_name(self, id: DefId) -> ast::Name {
|
|
if let Some(id) = self.map.as_local_node_id(id) {
|
|
self.map.name(id)
|
|
} else if id.index == CRATE_DEF_INDEX {
|
|
token::intern(&self.sess.cstore.original_crate_name(id.krate))
|
|
} else {
|
|
let def_key = self.sess.cstore.def_key(id);
|
|
// The name of a StructCtor is that of its struct parent.
|
|
if let ast_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));
|
|
})
|
|
}
|
|
}
|
|
}
|
|
|
|
// Register a given item type
|
|
pub fn register_item_type(self, did: DefId, scheme: TypeScheme<'gcx>) {
|
|
self.tcache.borrow_mut().insert(did, scheme.ty);
|
|
self.generics.borrow_mut().insert(did, scheme.generics);
|
|
}
|
|
|
|
// If the given item is in an external crate, looks up its type and adds it to
|
|
// the type cache. Returns the type parameters and type.
|
|
pub fn lookup_item_type(self, did: DefId) -> TypeScheme<'gcx> {
|
|
let ty = lookup_locally_or_in_crate_store(
|
|
"tcache", did, &self.tcache,
|
|
|| self.sess.cstore.item_type(self.global_tcx(), did));
|
|
|
|
TypeScheme {
|
|
ty: ty,
|
|
generics: self.lookup_generics(did)
|
|
}
|
|
}
|
|
|
|
pub fn opt_lookup_item_type(self, did: DefId) -> Option<TypeScheme<'gcx>> {
|
|
if did.krate != LOCAL_CRATE {
|
|
return Some(self.lookup_item_type(did));
|
|
}
|
|
|
|
if let Some(ty) = self.tcache.borrow().get(&did).cloned() {
|
|
Some(TypeScheme {
|
|
ty: ty,
|
|
generics: self.lookup_generics(did)
|
|
})
|
|
} else {
|
|
None
|
|
}
|
|
}
|
|
|
|
/// Given the did of a trait, returns its canonical trait ref.
|
|
pub fn lookup_trait_def(self, did: DefId) -> &'gcx TraitDef<'gcx> {
|
|
lookup_locally_or_in_crate_store(
|
|
"trait_defs", did, &self.trait_defs,
|
|
|| self.alloc_trait_def(self.sess.cstore.trait_def(self.global_tcx(), did))
|
|
)
|
|
}
|
|
|
|
/// Given the did of an ADT, return a master reference to its
|
|
/// definition. Unless you are planning on fulfilling the ADT's fields,
|
|
/// use lookup_adt_def instead.
|
|
pub fn lookup_adt_def_master(self, did: DefId) -> AdtDefMaster<'gcx> {
|
|
lookup_locally_or_in_crate_store(
|
|
"adt_defs", did, &self.adt_defs,
|
|
|| self.sess.cstore.adt_def(self.global_tcx(), did)
|
|
)
|
|
}
|
|
|
|
/// Given the did of an ADT, return a reference to its definition.
|
|
pub fn lookup_adt_def(self, did: DefId) -> AdtDef<'gcx> {
|
|
// when reverse-variance goes away, a transmute::<AdtDefMaster,AdtDef>
|
|
// would be needed here.
|
|
self.lookup_adt_def_master(did)
|
|
}
|
|
|
|
/// Given the did of an item, returns its generics.
|
|
pub fn lookup_generics(self, did: DefId) -> &'gcx Generics<'gcx> {
|
|
lookup_locally_or_in_crate_store(
|
|
"generics", did, &self.generics,
|
|
|| self.alloc_generics(self.sess.cstore.item_generics(self.global_tcx(), did)))
|
|
}
|
|
|
|
/// Given the did of an item, returns its full set of predicates.
|
|
pub fn lookup_predicates(self, did: DefId) -> GenericPredicates<'gcx> {
|
|
lookup_locally_or_in_crate_store(
|
|
"predicates", did, &self.predicates,
|
|
|| self.sess.cstore.item_predicates(self.global_tcx(), did))
|
|
}
|
|
|
|
/// Given the did of a trait, returns its superpredicates.
|
|
pub fn lookup_super_predicates(self, did: DefId) -> GenericPredicates<'gcx> {
|
|
lookup_locally_or_in_crate_store(
|
|
"super_predicates", did, &self.super_predicates,
|
|
|| self.sess.cstore.item_super_predicates(self.global_tcx(), did))
|
|
}
|
|
|
|
/// If `type_needs_drop` returns true, then `ty` is definitely
|
|
/// non-copy and *might* have a destructor attached; if it returns
|
|
/// false, then `ty` definitely has no destructor (i.e. no drop glue).
|
|
///
|
|
/// (Note that this implies that if `ty` has a destructor attached,
|
|
/// then `type_needs_drop` will definitely return `true` for `ty`.)
|
|
pub fn type_needs_drop_given_env(self,
|
|
ty: Ty<'gcx>,
|
|
param_env: &ty::ParameterEnvironment<'gcx>) -> bool {
|
|
// Issue #22536: We first query type_moves_by_default. It sees a
|
|
// normalized version of the type, and therefore will definitely
|
|
// know whether the type implements Copy (and thus needs no
|
|
// cleanup/drop/zeroing) ...
|
|
let tcx = self.global_tcx();
|
|
let implements_copy = !ty.moves_by_default(tcx, param_env, DUMMY_SP);
|
|
|
|
if implements_copy { return false; }
|
|
|
|
// ... (issue #22536 continued) but as an optimization, still use
|
|
// prior logic of asking if the `needs_drop` bit is set; we need
|
|
// not zero non-Copy types if they have no destructor.
|
|
|
|
// FIXME(#22815): Note that calling `ty::type_contents` is a
|
|
// conservative heuristic; it may report that `needs_drop` is set
|
|
// when actual type does not actually have a destructor associated
|
|
// with it. But since `ty` absolutely did not have the `Copy`
|
|
// bound attached (see above), it is sound to treat it as having a
|
|
// destructor (e.g. zero its memory on move).
|
|
|
|
let contents = ty.type_contents(tcx);
|
|
debug!("type_needs_drop ty={:?} contents={:?}", ty, contents);
|
|
contents.needs_drop(tcx)
|
|
}
|
|
|
|
/// Get the attributes of a definition.
|
|
pub fn get_attrs(self, did: DefId) -> Cow<'gcx, [ast::Attribute]> {
|
|
if let Some(id) = self.map.as_local_node_id(did) {
|
|
Cow::Borrowed(self.map.attrs(id))
|
|
} else {
|
|
Cow::Owned(self.sess.cstore.item_attrs(did))
|
|
}
|
|
}
|
|
|
|
/// Determine whether an item is annotated with an attribute
|
|
pub fn has_attr(self, did: DefId, attr: &str) -> bool {
|
|
self.get_attrs(did).iter().any(|item| item.check_name(attr))
|
|
}
|
|
|
|
/// Determine whether an item is annotated with `#[repr(packed)]`
|
|
pub fn lookup_packed(self, did: DefId) -> bool {
|
|
self.lookup_repr_hints(did).contains(&attr::ReprPacked)
|
|
}
|
|
|
|
/// Determine whether an item is annotated with `#[simd]`
|
|
pub fn lookup_simd(self, did: DefId) -> bool {
|
|
self.has_attr(did, "simd")
|
|
|| self.lookup_repr_hints(did).contains(&attr::ReprSimd)
|
|
}
|
|
|
|
pub fn item_variances(self, item_id: DefId) -> Rc<Vec<ty::Variance>> {
|
|
lookup_locally_or_in_crate_store(
|
|
"item_variance_map", item_id, &self.item_variance_map,
|
|
|| Rc::new(self.sess.cstore.item_variances(item_id)))
|
|
}
|
|
|
|
pub fn trait_has_default_impl(self, trait_def_id: DefId) -> bool {
|
|
self.populate_implementations_for_trait_if_necessary(trait_def_id);
|
|
|
|
let def = self.lookup_trait_def(trait_def_id);
|
|
def.flags.get().intersects(TraitFlags::HAS_DEFAULT_IMPL)
|
|
}
|
|
|
|
/// Records a trait-to-implementation mapping.
|
|
pub fn record_trait_has_default_impl(self, trait_def_id: DefId) {
|
|
let def = self.lookup_trait_def(trait_def_id);
|
|
def.flags.set(def.flags.get() | TraitFlags::HAS_DEFAULT_IMPL)
|
|
}
|
|
|
|
/// Load primitive inherent implementations if necessary
|
|
pub fn populate_implementations_for_primitive_if_necessary(self,
|
|
primitive_def_id: DefId) {
|
|
if primitive_def_id.is_local() {
|
|
return
|
|
}
|
|
|
|
// The primitive is not local, hence we are reading this out
|
|
// of metadata.
|
|
let _ignore = self.dep_graph.in_ignore();
|
|
|
|
if self.populated_external_primitive_impls.borrow().contains(&primitive_def_id) {
|
|
return
|
|
}
|
|
|
|
debug!("populate_implementations_for_primitive_if_necessary: searching for {:?}",
|
|
primitive_def_id);
|
|
|
|
let impl_items = self.sess.cstore.impl_or_trait_items(primitive_def_id);
|
|
|
|
// Store the implementation info.
|
|
self.impl_or_trait_item_def_ids.borrow_mut().insert(primitive_def_id, Rc::new(impl_items));
|
|
self.populated_external_primitive_impls.borrow_mut().insert(primitive_def_id);
|
|
}
|
|
|
|
/// Populates the type context with all the inherent implementations for
|
|
/// the given type if necessary.
|
|
pub fn populate_inherent_implementations_for_type_if_necessary(self,
|
|
type_id: DefId) {
|
|
if type_id.is_local() {
|
|
return
|
|
}
|
|
|
|
// The type is not local, hence we are reading this out of
|
|
// metadata and don't need to track edges.
|
|
let _ignore = self.dep_graph.in_ignore();
|
|
|
|
if self.populated_external_types.borrow().contains(&type_id) {
|
|
return
|
|
}
|
|
|
|
debug!("populate_inherent_implementations_for_type_if_necessary: searching for {:?}",
|
|
type_id);
|
|
|
|
let inherent_impls = self.sess.cstore.inherent_implementations_for_type(type_id);
|
|
for &impl_def_id in &inherent_impls {
|
|
// Store the implementation info.
|
|
let impl_items = self.sess.cstore.impl_or_trait_items(impl_def_id);
|
|
self.impl_or_trait_item_def_ids.borrow_mut().insert(impl_def_id, Rc::new(impl_items));
|
|
}
|
|
|
|
self.inherent_impls.borrow_mut().insert(type_id, inherent_impls);
|
|
self.populated_external_types.borrow_mut().insert(type_id);
|
|
}
|
|
|
|
/// Populates the type context with all the implementations for the given
|
|
/// trait if necessary.
|
|
pub fn populate_implementations_for_trait_if_necessary(self, trait_id: DefId) {
|
|
if trait_id.is_local() {
|
|
return
|
|
}
|
|
|
|
// The type is not local, hence we are reading this out of
|
|
// metadata and don't need to track edges.
|
|
let _ignore = self.dep_graph.in_ignore();
|
|
|
|
let def = self.lookup_trait_def(trait_id);
|
|
if def.flags.get().intersects(TraitFlags::IMPLS_VALID) {
|
|
return;
|
|
}
|
|
|
|
debug!("populate_implementations_for_trait_if_necessary: searching for {:?}", def);
|
|
|
|
if self.sess.cstore.is_defaulted_trait(trait_id) {
|
|
self.record_trait_has_default_impl(trait_id);
|
|
}
|
|
|
|
for impl_def_id in self.sess.cstore.implementations_of_trait(Some(trait_id)) {
|
|
let impl_items = self.sess.cstore.impl_or_trait_items(impl_def_id);
|
|
let trait_ref = self.impl_trait_ref(impl_def_id).unwrap();
|
|
|
|
// Record the trait->implementation mapping.
|
|
let parent = self.sess.cstore.impl_parent(impl_def_id).unwrap_or(trait_id);
|
|
def.record_remote_impl(self, impl_def_id, trait_ref, parent);
|
|
|
|
// For any methods that use a default implementation, add them to
|
|
// the map. This is a bit unfortunate.
|
|
for &impl_item_def_id in &impl_items {
|
|
// load impl items eagerly for convenience
|
|
// FIXME: we may want to load these lazily
|
|
self.impl_or_trait_item(impl_item_def_id);
|
|
}
|
|
|
|
// Store the implementation info.
|
|
self.impl_or_trait_item_def_ids.borrow_mut().insert(impl_def_id, Rc::new(impl_items));
|
|
}
|
|
|
|
def.flags.set(def.flags.get() | TraitFlags::IMPLS_VALID);
|
|
}
|
|
|
|
pub fn closure_kind(self, def_id: DefId) -> ty::ClosureKind {
|
|
// If this is a local def-id, it should be inserted into the
|
|
// tables by typeck; else, it will be retreived from
|
|
// the external crate metadata.
|
|
if let Some(&kind) = self.tables.borrow().closure_kinds.get(&def_id) {
|
|
return kind;
|
|
}
|
|
|
|
let kind = self.sess.cstore.closure_kind(def_id);
|
|
self.tables.borrow_mut().closure_kinds.insert(def_id, kind);
|
|
kind
|
|
}
|
|
|
|
pub fn closure_type(self,
|
|
def_id: DefId,
|
|
substs: ClosureSubsts<'tcx>)
|
|
-> ty::ClosureTy<'tcx>
|
|
{
|
|
// If this is a local def-id, it should be inserted into the
|
|
// tables by typeck; else, it will be retreived from
|
|
// the external crate metadata.
|
|
if let Some(ty) = self.tables.borrow().closure_tys.get(&def_id) {
|
|
return ty.subst(self, substs.func_substs);
|
|
}
|
|
|
|
let ty = self.sess.cstore.closure_ty(self.global_tcx(), def_id);
|
|
self.tables.borrow_mut().closure_tys.insert(def_id, ty.clone());
|
|
ty.subst(self, substs.func_substs)
|
|
}
|
|
|
|
/// 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 def ID describes a method belonging to an impl, return the
|
|
/// ID of the impl that the method belongs to. Otherwise, return `None`.
|
|
pub fn impl_of_method(self, def_id: DefId) -> Option<DefId> {
|
|
if def_id.krate != LOCAL_CRATE {
|
|
return self.sess.cstore.impl_or_trait_item(self.global_tcx(), def_id)
|
|
.and_then(|item| {
|
|
match item.container() {
|
|
TraitContainer(_) => None,
|
|
ImplContainer(def_id) => Some(def_id),
|
|
}
|
|
});
|
|
}
|
|
match self.impl_or_trait_items.borrow().get(&def_id).cloned() {
|
|
Some(trait_item) => {
|
|
match trait_item.container() {
|
|
TraitContainer(_) => None,
|
|
ImplContainer(def_id) => Some(def_id),
|
|
}
|
|
}
|
|
None => None
|
|
}
|
|
}
|
|
|
|
/// 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`.
|
|
pub fn trait_of_item(self, def_id: DefId) -> Option<DefId> {
|
|
if def_id.krate != LOCAL_CRATE {
|
|
return self.sess.cstore.trait_of_item(def_id);
|
|
}
|
|
match self.impl_or_trait_items.borrow().get(&def_id) {
|
|
Some(impl_or_trait_item) => {
|
|
match impl_or_trait_item.container() {
|
|
TraitContainer(def_id) => Some(def_id),
|
|
ImplContainer(_) => None
|
|
}
|
|
}
|
|
None => None
|
|
}
|
|
}
|
|
|
|
/// If the given def ID describes an item belonging to a trait, (either a
|
|
/// default method or an implementation of a trait method), return the ID of
|
|
/// the method inside trait definition (this means that if the given def ID
|
|
/// is already that of the original trait method, then the return value is
|
|
/// the same).
|
|
/// Otherwise, return `None`.
|
|
pub fn trait_item_of_item(self, def_id: DefId) -> Option<DefId> {
|
|
let impl_or_trait_item = match self.impl_or_trait_items.borrow().get(&def_id) {
|
|
Some(m) => m.clone(),
|
|
None => return None,
|
|
};
|
|
match impl_or_trait_item.container() {
|
|
TraitContainer(_) => Some(impl_or_trait_item.def_id()),
|
|
ImplContainer(def_id) => {
|
|
self.trait_id_of_impl(def_id).and_then(|trait_did| {
|
|
let name = impl_or_trait_item.name();
|
|
self.trait_items(trait_did).iter()
|
|
.find(|item| item.name() == name)
|
|
.map(|item| item.def_id())
|
|
})
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Construct a parameter environment suitable for static contexts or other contexts where there
|
|
/// are no free type/lifetime parameters in scope.
|
|
pub fn empty_parameter_environment(self) -> ParameterEnvironment<'tcx> {
|
|
|
|
// for an empty parameter environment, there ARE no free
|
|
// regions, so it shouldn't matter what we use for the free id
|
|
let free_id_outlive = self.region_maps.node_extent(ast::DUMMY_NODE_ID);
|
|
ty::ParameterEnvironment {
|
|
free_substs: Substs::empty(self),
|
|
caller_bounds: Vec::new(),
|
|
implicit_region_bound: self.mk_region(ty::ReEmpty),
|
|
free_id_outlive: free_id_outlive,
|
|
is_copy_cache: RefCell::new(FnvHashMap()),
|
|
is_sized_cache: RefCell::new(FnvHashMap()),
|
|
}
|
|
}
|
|
|
|
/// Constructs and returns a substitution that can be applied to move from
|
|
/// the "outer" view of a type or method to the "inner" view.
|
|
/// In general, this means converting from bound parameters to
|
|
/// free parameters. Since we currently represent bound/free type
|
|
/// parameters in the same way, this only has an effect on regions.
|
|
pub fn construct_free_substs(self, def_id: DefId,
|
|
free_id_outlive: CodeExtent)
|
|
-> &'gcx Substs<'gcx> {
|
|
|
|
let substs = Substs::for_item(self.global_tcx(), def_id, |def, _| {
|
|
// map bound 'a => free 'a
|
|
self.global_tcx().mk_region(ReFree(FreeRegion {
|
|
scope: free_id_outlive,
|
|
bound_region: def.to_bound_region()
|
|
}))
|
|
}, |def, _| {
|
|
// map T => T
|
|
self.global_tcx().mk_param_from_def(def)
|
|
});
|
|
|
|
debug!("construct_parameter_environment: {:?}", substs);
|
|
substs
|
|
}
|
|
|
|
/// See `ParameterEnvironment` struct def'n for details.
|
|
/// If you were using `free_id: NodeId`, you might try `self.region_maps.item_extent(free_id)`
|
|
/// for the `free_id_outlive` parameter. (But note that this is not always quite right.)
|
|
pub fn construct_parameter_environment(self,
|
|
span: Span,
|
|
def_id: DefId,
|
|
free_id_outlive: CodeExtent)
|
|
-> ParameterEnvironment<'gcx>
|
|
{
|
|
//
|
|
// Construct the free substs.
|
|
//
|
|
|
|
let free_substs = self.construct_free_substs(def_id, free_id_outlive);
|
|
|
|
//
|
|
// Compute the bounds on Self and the type parameters.
|
|
//
|
|
|
|
let tcx = self.global_tcx();
|
|
let generic_predicates = tcx.lookup_predicates(def_id);
|
|
let bounds = generic_predicates.instantiate(tcx, free_substs);
|
|
let bounds = tcx.liberate_late_bound_regions(free_id_outlive, &ty::Binder(bounds));
|
|
let predicates = bounds.predicates;
|
|
|
|
// 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::ParameterEnvironment {
|
|
free_substs: free_substs,
|
|
implicit_region_bound: tcx.mk_region(ty::ReScope(free_id_outlive)),
|
|
caller_bounds: predicates,
|
|
free_id_outlive: free_id_outlive,
|
|
is_copy_cache: RefCell::new(FnvHashMap()),
|
|
is_sized_cache: RefCell::new(FnvHashMap()),
|
|
};
|
|
|
|
let cause = traits::ObligationCause::misc(span, free_id_outlive.node_id(&self.region_maps));
|
|
traits::normalize_param_env_or_error(tcx, unnormalized_env, cause)
|
|
}
|
|
|
|
pub fn node_scope_region(self, id: NodeId) -> &'tcx Region {
|
|
self.mk_region(ty::ReScope(self.region_maps.node_extent(id)))
|
|
}
|
|
|
|
pub fn is_method_call(self, expr_id: NodeId) -> bool {
|
|
self.tables.borrow().method_map.contains_key(&MethodCall::expr(expr_id))
|
|
}
|
|
|
|
pub fn is_overloaded_autoderef(self, expr_id: NodeId, autoderefs: u32) -> bool {
|
|
self.tables.borrow().method_map.contains_key(&MethodCall::autoderef(expr_id,
|
|
autoderefs))
|
|
}
|
|
|
|
pub fn upvar_capture(self, upvar_id: ty::UpvarId) -> Option<ty::UpvarCapture<'tcx>> {
|
|
Some(self.tables.borrow().upvar_capture_map.get(&upvar_id).unwrap().clone())
|
|
}
|
|
|
|
pub fn visit_all_items_in_krate<V,F>(self,
|
|
dep_node_fn: F,
|
|
visitor: &mut V)
|
|
where F: FnMut(DefId) -> DepNode<DefId>, V: Visitor<'gcx>
|
|
{
|
|
dep_graph::visit_all_items_in_krate(self.global_tcx(), dep_node_fn, visitor);
|
|
}
|
|
|
|
/// 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, InternedString> {
|
|
if impl_did.is_local() {
|
|
let node_id = self.map.as_local_node_id(impl_did).unwrap();
|
|
Ok(self.map.span(node_id))
|
|
} else {
|
|
Err(self.sess.cstore.crate_name(impl_did.krate))
|
|
}
|
|
}
|
|
}
|
|
|
|
/// The category of explicit self.
|
|
#[derive(Clone, Copy, Eq, PartialEq, Debug, RustcEncodable, RustcDecodable)]
|
|
pub enum ExplicitSelfCategory<'tcx> {
|
|
Static,
|
|
ByValue,
|
|
ByReference(&'tcx Region, hir::Mutability),
|
|
ByBox,
|
|
}
|
|
|
|
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,
|
|
{
|
|
match self.freevars.borrow().get(&fid) {
|
|
None => f(&[]),
|
|
Some(d) => f(&d[..])
|
|
}
|
|
}
|
|
}
|