// Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT // file at the top-level directory of this distribution and at // http://rust-lang.org/COPYRIGHT. // // Licensed under the Apache License, Version 2.0 or the MIT license // , at your // option. This file may not be copied, modified, or distributed // except according to those terms. //! type context book-keeping use dep_graph::{DepGraph, DepTrackingMap}; use session::Session; use lint; use middle; use middle::cstore::LOCAL_CRATE; use hir::def::DefMap; use hir::def_id::{DefId, DefIndex}; use hir::map as ast_map; use hir::map::{DefKey, DefPath, DefPathData, DisambiguatedDefPathData}; use middle::free_region::FreeRegionMap; use middle::region::RegionMaps; use middle::resolve_lifetime; use middle::stability; use ty::subst::{self, Substs}; use traits; use ty::{self, TraitRef, Ty, TypeAndMut}; use ty::{TyS, TypeVariants}; use ty::{AdtDef, ClosureSubsts, ExistentialBounds, Region}; use hir::FreevarMap; use ty::{BareFnTy, InferTy, ParamTy, ProjectionTy, TraitTy}; use ty::{TyVar, TyVid, IntVar, IntVid, FloatVar, FloatVid}; use ty::TypeVariants::*; use ty::layout::{Layout, TargetDataLayout}; use ty::maps; use util::common::MemoizationMap; use util::nodemap::{NodeMap, NodeSet, DefIdMap, DefIdSet}; use util::nodemap::{FnvHashMap, FnvHashSet}; use arena::TypedArena; use std::borrow::Borrow; use std::cell::{Cell, RefCell, Ref}; use std::hash::{Hash, Hasher}; use std::mem; use std::ops::Deref; use std::rc::Rc; use syntax::ast::{self, Name, NodeId}; use syntax::attr; use syntax::parse::token::{self, keywords}; use hir; /// Internal storage pub struct CtxtArenas<'tcx> { // internings type_: TypedArena>, type_list: TypedArena>>, substs: TypedArena>, bare_fn: TypedArena>, region: TypedArena, stability: TypedArena, layout: TypedArena, // references trait_defs: TypedArena>, adt_defs: TypedArena>, } impl<'tcx> CtxtArenas<'tcx> { pub fn new() -> CtxtArenas<'tcx> { CtxtArenas { type_: TypedArena::new(), type_list: TypedArena::new(), substs: TypedArena::new(), bare_fn: TypedArena::new(), region: TypedArena::new(), stability: TypedArena::new(), layout: TypedArena::new(), trait_defs: TypedArena::new(), adt_defs: TypedArena::new() } } } pub struct CtxtInterners<'tcx> { /// The arenas that types etc are allocated from. arenas: &'tcx CtxtArenas<'tcx>, /// Specifically use a speedy hash algorithm for these hash sets, /// they're accessed quite often. type_: RefCell>>>, type_list: RefCell]>>>, substs: RefCell>>>, bare_fn: RefCell>>>, region: RefCell>>, stability: RefCell>, layout: RefCell>, } impl<'gcx: 'tcx, 'tcx> CtxtInterners<'tcx> { fn new(arenas: &'tcx CtxtArenas<'tcx>) -> CtxtInterners<'tcx> { CtxtInterners { arenas: arenas, type_: RefCell::new(FnvHashSet()), type_list: RefCell::new(FnvHashSet()), substs: RefCell::new(FnvHashSet()), bare_fn: RefCell::new(FnvHashSet()), region: RefCell::new(FnvHashSet()), stability: RefCell::new(FnvHashSet()), layout: RefCell::new(FnvHashSet()) } } /// Intern a type. global_interners is Some only if this is /// a local interner and global_interners is its counterpart. fn intern_ty(&self, st: TypeVariants<'tcx>, global_interners: Option<&CtxtInterners<'gcx>>) -> Ty<'tcx> { let ty = { let mut interner = self.type_.borrow_mut(); let global_interner = global_interners.map(|interners| { interners.type_.borrow_mut() }); if let Some(&Interned(ty)) = interner.get(&st) { return ty; } if let Some(ref interner) = global_interner { if let Some(&Interned(ty)) = interner.get(&st) { return ty; } } let flags = super::flags::FlagComputation::for_sty(&st); let ty_struct = TyS { sty: st, flags: Cell::new(flags.flags), region_depth: flags.depth, }; // HACK(eddyb) Depend on flags being accurate to // determine that all contents are in the global tcx. // See comments on Lift for why we can't use that. if !flags.flags.intersects(ty::TypeFlags::KEEP_IN_LOCAL_TCX) { if let Some(interner) = global_interners { let ty_struct: TyS<'gcx> = unsafe { mem::transmute(ty_struct) }; let ty: Ty<'gcx> = interner.arenas.type_.alloc(ty_struct); global_interner.unwrap().insert(Interned(ty)); return ty; } } else { // Make sure we don't end up with inference // types/regions in the global tcx. if global_interners.is_none() { drop(interner); bug!("Attempted to intern `{:?}` which contains \ inference types/regions in the global type context", &ty_struct); } } // Don't be &mut TyS. let ty: Ty<'tcx> = self.arenas.type_.alloc(ty_struct); interner.insert(Interned(ty)); ty }; debug!("Interned type: {:?} Pointer: {:?}", ty, ty as *const TyS); ty } } pub struct CommonTypes<'tcx> { pub bool: Ty<'tcx>, pub char: Ty<'tcx>, pub isize: Ty<'tcx>, pub i8: Ty<'tcx>, pub i16: Ty<'tcx>, pub i32: Ty<'tcx>, pub i64: Ty<'tcx>, pub usize: Ty<'tcx>, pub u8: Ty<'tcx>, pub u16: Ty<'tcx>, pub u32: Ty<'tcx>, pub u64: Ty<'tcx>, pub f32: Ty<'tcx>, pub f64: Ty<'tcx>, pub err: Ty<'tcx>, } pub struct Tables<'tcx> { /// Stores the types for various nodes in the AST. Note that this table /// is not guaranteed to be populated until after typeck. See /// typeck::check::fn_ctxt for details. pub node_types: NodeMap>, /// Stores the type parameters which were substituted to obtain the type /// of this node. This only applies to nodes that refer to entities /// parameterized by type parameters, such as generic fns, types, or /// other items. pub item_substs: NodeMap>, pub adjustments: NodeMap>, pub method_map: ty::MethodMap<'tcx>, /// Borrows pub upvar_capture_map: ty::UpvarCaptureMap, /// Records the type of each closure. The def ID is the ID of the /// expression defining the closure. pub closure_tys: DefIdMap>, /// Records the type of each closure. The def ID is the ID of the /// expression defining the closure. pub closure_kinds: DefIdMap, /// For each fn, records the "liberated" types of its arguments /// and return type. Liberated means that all bound regions /// (including late-bound regions) are replaced with free /// equivalents. This table is not used in trans (since regions /// are erased there) and hence is not serialized to metadata. pub liberated_fn_sigs: NodeMap>, /// For each FRU expression, record the normalized types of the fields /// of the struct - this is needed because it is non-trivial to /// normalize while preserving regions. This table is used only in /// MIR construction and hence is not serialized to metadata. pub fru_field_types: NodeMap>> } impl<'a, 'gcx, 'tcx> Tables<'tcx> { pub fn empty() -> Tables<'tcx> { Tables { node_types: FnvHashMap(), item_substs: NodeMap(), adjustments: NodeMap(), method_map: FnvHashMap(), upvar_capture_map: FnvHashMap(), closure_tys: DefIdMap(), closure_kinds: DefIdMap(), liberated_fn_sigs: NodeMap(), fru_field_types: NodeMap() } } } impl<'tcx> CommonTypes<'tcx> { fn new(interners: &CtxtInterners<'tcx>) -> CommonTypes<'tcx> { let mk = |sty| interners.intern_ty(sty, None); CommonTypes { bool: mk(TyBool), char: mk(TyChar), err: mk(TyError), isize: mk(TyInt(ast::IntTy::Is)), i8: mk(TyInt(ast::IntTy::I8)), i16: mk(TyInt(ast::IntTy::I16)), i32: mk(TyInt(ast::IntTy::I32)), i64: mk(TyInt(ast::IntTy::I64)), usize: mk(TyUint(ast::UintTy::Us)), u8: mk(TyUint(ast::UintTy::U8)), u16: mk(TyUint(ast::UintTy::U16)), u32: mk(TyUint(ast::UintTy::U32)), u64: mk(TyUint(ast::UintTy::U64)), f32: mk(TyFloat(ast::FloatTy::F32)), f64: mk(TyFloat(ast::FloatTy::F64)), } } } /// The data structure to keep track of all the information that typechecker /// generates so that so that it can be reused and doesn't have to be redone /// later on. #[derive(Copy, Clone)] pub struct TyCtxt<'a, 'gcx: 'a+'tcx, 'tcx: 'a> { gcx: &'a GlobalCtxt<'gcx>, interners: &'a CtxtInterners<'tcx> } impl<'a, 'gcx, 'tcx> Deref for TyCtxt<'a, 'gcx, 'tcx> { type Target = &'a GlobalCtxt<'gcx>; fn deref(&self) -> &Self::Target { &self.gcx } } pub struct GlobalCtxt<'tcx> { global_interners: CtxtInterners<'tcx>, pub specializes_cache: RefCell, pub dep_graph: DepGraph, /// Common types, pre-interned for your convenience. pub types: CommonTypes<'tcx>, pub sess: &'tcx Session, pub def_map: RefCell, pub named_region_map: resolve_lifetime::NamedRegionMap, pub region_maps: RegionMaps, // For each fn declared in the local crate, type check stores the // free-region relationships that were deduced from its where // clauses and parameter types. These are then read-again by // borrowck. (They are not used during trans, and hence are not // serialized or needed for cross-crate fns.) free_region_maps: RefCell>, // FIXME: jroesch make this a refcell pub tables: RefCell>, /// Maps from a trait item to the trait item "descriptor" pub impl_or_trait_items: RefCell>>, /// Maps from a trait def-id to a list of the def-ids of its trait items pub trait_item_def_ids: RefCell>>, /// A cache for the trait_items() routine; note that the routine /// itself pushes the `TraitItems` dependency node. trait_items_cache: RefCell>>, pub impl_trait_refs: RefCell>>, pub trait_defs: RefCell>>, pub adt_defs: RefCell>>, /// Maps from the def-id of an item (trait/struct/enum/fn) to its /// associated predicates. pub predicates: RefCell>>, /// Maps from the def-id of a trait to the list of /// super-predicates. This is a subset of the full list of /// predicates. We store these in a separate map because we must /// evaluate them even during type conversion, often before the /// full predicates are available (note that supertraits have /// additional acyclicity requirements). pub super_predicates: RefCell>>, pub map: ast_map::Map<'tcx>, // Records the free variables refrenced by every closure // expression. Do not track deps for this, just recompute it from // scratch every time. pub freevars: RefCell, pub maybe_unused_trait_imports: NodeSet, // Records the type of every item. pub tcache: RefCell>>, // Internal cache for metadata decoding. No need to track deps on this. pub rcache: RefCell>>, // Cache for the type-contents routine. FIXME -- track deps? pub tc_cache: RefCell, ty::contents::TypeContents>>, // FIXME no dep tracking, but we should be able to remove this pub ty_param_defs: RefCell>>, // FIXME dep tracking -- should be harmless enough pub normalized_cache: RefCell, Ty<'tcx>>>, pub lang_items: middle::lang_items::LanguageItems, /// Maps from def-id of a type or region parameter to its /// (inferred) variance. pub item_variance_map: RefCell>>, /// True if the variance has been computed yet; false otherwise. pub variance_computed: Cell, /// Maps a DefId of a type to a list of its inherent impls. /// Contains implementations of methods that are inherent to a type. /// Methods in these implementations don't need to be exported. pub inherent_impls: RefCell>>, /// Maps a DefId of an impl to a list of its items. /// Note that this contains all of the impls that we know about, /// including ones in other crates. It's not clear that this is the best /// way to do it. pub impl_items: RefCell>>, /// Set of used unsafe nodes (functions or blocks). Unsafe nodes not /// present in this set can be warned about. pub used_unsafe: RefCell, /// Set of nodes which mark locals as mutable which end up getting used at /// some point. Local variable definitions not in this set can be warned /// about. pub used_mut_nodes: RefCell, /// Set of trait imports actually used in the method resolution. /// This is used for warning unused imports. pub used_trait_imports: RefCell, /// The set of external nominal types whose implementations have been read. /// This is used for lazy resolution of methods. pub populated_external_types: RefCell, /// The set of external primitive types whose implementations have been read. /// FIXME(arielb1): why is this separate from populated_external_types? pub populated_external_primitive_impls: RefCell, /// Cache used by const_eval when decoding external constants. /// Contains `None` when the constant has been fetched but doesn't exist. /// Constains `Some(expr_id, type)` otherwise. /// `type` is `None` in case it's not a primitive type pub extern_const_statics: RefCell>)>>>, /// Cache used by const_eval when decoding extern const fns pub extern_const_fns: RefCell>, pub node_lint_levels: RefCell>, /// Maps any item's def-id to its stability index. pub stability: RefCell>, /// Caches the results of trait selection. This cache is used /// for things that do not have to do with the parameters in scope. pub selection_cache: traits::SelectionCache<'tcx>, /// Caches the results of trait evaluation. This cache is used /// for things that do not have to do with the parameters in scope. /// Merge this with `selection_cache`? pub evaluation_cache: traits::EvaluationCache<'tcx>, /// A set of predicates that have been fulfilled *somewhere*. /// This is used to avoid duplicate work. Predicates are only /// added to this set when they mention only "global" names /// (i.e., no type or lifetime parameters). pub fulfilled_predicates: RefCell>, /// Caches the representation hints for struct definitions. repr_hint_cache: RefCell>>, /// Maps Expr NodeId's to their constant qualification. pub const_qualif_map: RefCell>, /// Caches CoerceUnsized kinds for impls on custom types. pub custom_coerce_unsized_kinds: RefCell>, /// Maps a cast expression to its kind. This is keyed on the /// *from* expression of the cast, not the cast itself. pub cast_kinds: RefCell>, /// Maps Fn items to a collection of fragment infos. /// /// The main goal is to identify data (each of which may be moved /// or assigned) whose subparts are not moved nor assigned /// (i.e. their state is *unfragmented*) and corresponding ast /// nodes where the path to that data is moved or assigned. /// /// In the long term, unfragmented values will have their /// destructor entirely driven by a single stack-local drop-flag, /// and their parents, the collections of the unfragmented values /// (or more simply, "fragmented values"), are mapped to the /// corresponding collections of stack-local drop-flags. /// /// (However, in the short term that is not the case; e.g. some /// unfragmented paths still need to be zeroed, namely when they /// reference parent data from an outer scope that was not /// entirely moved, and therefore that needs to be zeroed so that /// we do not get double-drop when we hit the end of the parent /// scope.) /// /// Also: currently the table solely holds keys for node-ids of /// unfragmented values (see `FragmentInfo` enum definition), but /// longer-term we will need to also store mappings from /// fragmented data to the set of unfragmented pieces that /// constitute it. pub fragment_infos: RefCell>>, /// The definite name of the current crate after taking into account /// attributes, commandline parameters, etc. pub crate_name: token::InternedString, /// Data layout specification for the current target. pub data_layout: TargetDataLayout, /// Cache for layouts computed from types. pub layout_cache: RefCell, &'tcx Layout>>, } impl<'tcx> GlobalCtxt<'tcx> { /// Get the global TyCtxt. pub fn global_tcx<'a>(&'a self) -> TyCtxt<'a, 'tcx, 'tcx> { TyCtxt { gcx: self, interners: &self.global_interners } } } impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> { pub fn crate_name(self, cnum: ast::CrateNum) -> token::InternedString { if cnum == LOCAL_CRATE { self.crate_name.clone() } else { self.sess.cstore.crate_name(cnum) } } pub fn crate_disambiguator(self, cnum: ast::CrateNum) -> token::InternedString { if cnum == LOCAL_CRATE { self.sess.crate_disambiguator.get().as_str() } else { self.sess.cstore.crate_disambiguator(cnum) } } /// Given a def-key `key` and a crate `krate`, finds the def-index /// that `krate` assigned to `key`. This `DefIndex` will always be /// relative to `krate`. /// /// Returns `None` if there is no `DefIndex` with that key. pub fn def_index_for_def_key(self, krate: ast::CrateNum, key: DefKey) -> Option { if krate == LOCAL_CRATE { self.map.def_index_for_def_key(key) } else { self.sess.cstore.def_index_for_def_key(krate, key) } } pub fn retrace_path(self, path: &DefPath) -> Option { debug!("retrace_path(path={:?})", path); let root_key = DefKey { parent: None, disambiguated_data: DisambiguatedDefPathData { data: DefPathData::CrateRoot, disambiguator: 0, }, }; let root_index = self.def_index_for_def_key(path.krate, root_key) .expect("no root key?"); debug!("retrace_path: root_index={:?}", root_index); let mut index = root_index; for data in &path.data { let key = DefKey { parent: Some(index), disambiguated_data: data.clone() }; debug!("retrace_path: key={:?}", key); match self.def_index_for_def_key(path.krate, key) { Some(i) => index = i, None => return None, } } Some(DefId { krate: path.krate, index: index }) } pub fn type_parameter_def(self, node_id: NodeId) -> ty::TypeParameterDef<'tcx> { self.ty_param_defs.borrow().get(&node_id).unwrap().clone() } pub fn node_types(self) -> Ref<'a, NodeMap>> { fn projection<'a, 'tcx>(tables: &'a Tables<'tcx>) -> &'a NodeMap> { &tables.node_types } Ref::map(self.tables.borrow(), projection) } pub fn node_type_insert(self, id: NodeId, ty: Ty<'gcx>) { self.tables.borrow_mut().node_types.insert(id, ty); } pub fn intern_trait_def(self, def: ty::TraitDef<'gcx>) -> &'gcx ty::TraitDef<'gcx> { let did = def.trait_ref.def_id; let interned = self.global_interners.arenas.trait_defs.alloc(def); if let Some(prev) = self.trait_defs.borrow_mut().insert(did, interned) { bug!("Tried to overwrite interned TraitDef: {:?}", prev) } interned } pub fn alloc_trait_def(self, def: ty::TraitDef<'gcx>) -> &'gcx ty::TraitDef<'gcx> { self.global_interners.arenas.trait_defs.alloc(def) } pub fn intern_adt_def(self, did: DefId, kind: ty::AdtKind, variants: Vec>) -> ty::AdtDefMaster<'gcx> { let def = ty::AdtDefData::new(self, did, kind, variants); let interned = self.global_interners.arenas.adt_defs.alloc(def); // this will need a transmute when reverse-variance is removed if let Some(prev) = self.adt_defs.borrow_mut().insert(did, interned) { bug!("Tried to overwrite interned AdtDef: {:?}", prev) } interned } pub fn intern_stability(self, stab: attr::Stability) -> &'gcx attr::Stability { if let Some(st) = self.global_interners.stability.borrow().get(&stab) { return st; } let interned = self.global_interners.arenas.stability.alloc(stab); if let Some(prev) = self.global_interners.stability .borrow_mut() .replace(interned) { bug!("Tried to overwrite interned Stability: {:?}", prev) } interned } pub fn intern_layout(self, layout: Layout) -> &'gcx Layout { if let Some(layout) = self.global_interners.layout.borrow().get(&layout) { return layout; } let interned = self.global_interners.arenas.layout.alloc(layout); if let Some(prev) = self.global_interners.layout .borrow_mut() .replace(interned) { bug!("Tried to overwrite interned Layout: {:?}", prev) } interned } pub fn store_free_region_map(self, id: NodeId, map: FreeRegionMap) { if self.free_region_maps.borrow_mut().insert(id, map).is_some() { bug!("Tried to overwrite interned FreeRegionMap for NodeId {:?}", id) } } pub fn free_region_map(self, id: NodeId) -> FreeRegionMap { self.free_region_maps.borrow()[&id].clone() } pub fn lift>(self, value: &T) -> Option { value.lift_to_tcx(self) } /// Like lift, but only tries in the global tcx. pub fn lift_to_global>(self, value: &T) -> Option { value.lift_to_tcx(self.global_tcx()) } /// Returns true if self is the same as self.global_tcx(). fn is_global(self) -> bool { let local = self.interners as *const _; let global = &self.global_interners as *const _; local as usize == global as usize } /// Create a type context and call the closure with a `TyCtxt` reference /// to the context. The closure enforces that the type context and any interned /// value (types, substs, etc.) can only be used while `ty::tls` has a valid /// reference to the context, to allow formatting values that need it. pub fn create_and_enter(s: &'tcx Session, arenas: &'tcx CtxtArenas<'tcx>, def_map: RefCell, named_region_map: resolve_lifetime::NamedRegionMap, map: ast_map::Map<'tcx>, freevars: FreevarMap, maybe_unused_trait_imports: NodeSet, region_maps: RegionMaps, lang_items: middle::lang_items::LanguageItems, stability: stability::Index<'tcx>, crate_name: &str, f: F) -> R where F: for<'b> FnOnce(TyCtxt<'b, 'tcx, 'tcx>) -> R { let data_layout = TargetDataLayout::parse(s); let interners = CtxtInterners::new(arenas); let common_types = CommonTypes::new(&interners); let dep_graph = map.dep_graph.clone(); let fulfilled_predicates = traits::GlobalFulfilledPredicates::new(dep_graph.clone()); tls::enter_global(GlobalCtxt { specializes_cache: RefCell::new(traits::SpecializesCache::new()), global_interners: interners, dep_graph: dep_graph.clone(), types: common_types, named_region_map: named_region_map, region_maps: region_maps, free_region_maps: RefCell::new(FnvHashMap()), item_variance_map: RefCell::new(DepTrackingMap::new(dep_graph.clone())), variance_computed: Cell::new(false), sess: s, def_map: def_map, tables: RefCell::new(Tables::empty()), impl_trait_refs: RefCell::new(DepTrackingMap::new(dep_graph.clone())), trait_defs: RefCell::new(DepTrackingMap::new(dep_graph.clone())), adt_defs: RefCell::new(DepTrackingMap::new(dep_graph.clone())), predicates: RefCell::new(DepTrackingMap::new(dep_graph.clone())), super_predicates: RefCell::new(DepTrackingMap::new(dep_graph.clone())), fulfilled_predicates: RefCell::new(fulfilled_predicates), map: map, freevars: RefCell::new(freevars), maybe_unused_trait_imports: maybe_unused_trait_imports, tcache: RefCell::new(DepTrackingMap::new(dep_graph.clone())), rcache: RefCell::new(FnvHashMap()), tc_cache: RefCell::new(FnvHashMap()), impl_or_trait_items: RefCell::new(DepTrackingMap::new(dep_graph.clone())), trait_item_def_ids: RefCell::new(DepTrackingMap::new(dep_graph.clone())), trait_items_cache: RefCell::new(DepTrackingMap::new(dep_graph.clone())), ty_param_defs: RefCell::new(NodeMap()), normalized_cache: RefCell::new(FnvHashMap()), lang_items: lang_items, inherent_impls: RefCell::new(DepTrackingMap::new(dep_graph.clone())), impl_items: RefCell::new(DepTrackingMap::new(dep_graph.clone())), used_unsafe: RefCell::new(NodeSet()), used_mut_nodes: RefCell::new(NodeSet()), used_trait_imports: RefCell::new(NodeSet()), populated_external_types: RefCell::new(DefIdSet()), populated_external_primitive_impls: RefCell::new(DefIdSet()), extern_const_statics: RefCell::new(DefIdMap()), extern_const_fns: RefCell::new(DefIdMap()), node_lint_levels: RefCell::new(FnvHashMap()), stability: RefCell::new(stability), selection_cache: traits::SelectionCache::new(), evaluation_cache: traits::EvaluationCache::new(), repr_hint_cache: RefCell::new(DepTrackingMap::new(dep_graph.clone())), const_qualif_map: RefCell::new(NodeMap()), custom_coerce_unsized_kinds: RefCell::new(DefIdMap()), cast_kinds: RefCell::new(NodeMap()), fragment_infos: RefCell::new(DefIdMap()), crate_name: token::intern_and_get_ident(crate_name), data_layout: data_layout, layout_cache: RefCell::new(FnvHashMap()), }, f) } } impl<'gcx: 'tcx, 'tcx> GlobalCtxt<'gcx> { /// Call the closure with a local `TyCtxt` using the given arenas. pub fn enter_local(&self, arenas: &'tcx CtxtArenas<'tcx>, f: F) -> R where F: for<'a> FnOnce(TyCtxt<'a, 'gcx, 'tcx>) -> R { let interners = CtxtInterners::new(arenas); tls::enter(self, &interners, f) } } /// A trait implemented for all X<'a> types which can be safely and /// efficiently converted to X<'tcx> as long as they are part of the /// provided TyCtxt<'tcx>. /// This can be done, for example, for Ty<'tcx> or &'tcx Substs<'tcx> /// by looking them up in their respective interners. /// /// However, this is still not the best implementation as it does /// need to compare the components, even for interned values. /// It would be more efficient if TypedArena provided a way to /// determine whether the address is in the allocated range. /// /// None is returned if the value or one of the components is not part /// of the provided context. /// For Ty, None can be returned if either the type interner doesn't /// contain the TypeVariants key or if the address of the interned /// pointer differs. The latter case is possible if a primitive type, /// e.g. `()` or `u8`, was interned in a different context. pub trait Lift<'tcx> { type Lifted; fn lift_to_tcx<'a, 'gcx>(&self, tcx: TyCtxt<'a, 'gcx, 'tcx>) -> Option; } impl<'a, 'tcx> Lift<'tcx> for Ty<'a> { type Lifted = Ty<'tcx>; fn lift_to_tcx<'b, 'gcx>(&self, tcx: TyCtxt<'b, 'gcx, 'tcx>) -> Option> { if let Some(&Interned(ty)) = tcx.interners.type_.borrow().get(&self.sty) { if *self as *const _ == ty as *const _ { return Some(ty); } } // Also try in the global tcx if we're not that. if !tcx.is_global() { self.lift_to_tcx(tcx.global_tcx()) } else { None } } } impl<'a, 'tcx> Lift<'tcx> for &'a Substs<'a> { type Lifted = &'tcx Substs<'tcx>; fn lift_to_tcx<'b, 'gcx>(&self, tcx: TyCtxt<'b, 'gcx, 'tcx>) -> Option<&'tcx Substs<'tcx>> { if let Some(&Interned(substs)) = tcx.interners.substs.borrow().get(*self) { if *self as *const _ == substs as *const _ { return Some(substs); } } // Also try in the global tcx if we're not that. if !tcx.is_global() { self.lift_to_tcx(tcx.global_tcx()) } else { None } } } impl<'a, 'tcx> Lift<'tcx> for &'a Region { type Lifted = &'tcx Region; fn lift_to_tcx<'b, 'gcx>(&self, tcx: TyCtxt<'b, 'gcx, 'tcx>) -> Option<&'tcx Region> { if let Some(&Interned(region)) = tcx.interners.region.borrow().get(*self) { if *self as *const _ == region as *const _ { return Some(region); } } // Also try in the global tcx if we're not that. if !tcx.is_global() { self.lift_to_tcx(tcx.global_tcx()) } else { None } } } impl<'a, 'tcx> Lift<'tcx> for &'a [Ty<'a>] { type Lifted = &'tcx [Ty<'tcx>]; fn lift_to_tcx<'b, 'gcx>(&self, tcx: TyCtxt<'b, 'gcx, 'tcx>) -> Option<&'tcx [Ty<'tcx>]> { if let Some(&Interned(list)) = tcx.interners.type_list.borrow().get(*self) { if *self as *const _ == list as *const _ { return Some(list); } } // Also try in the global tcx if we're not that. if !tcx.is_global() { self.lift_to_tcx(tcx.global_tcx()) } else { None } } } impl<'a, 'tcx> Lift<'tcx> for &'a BareFnTy<'a> { type Lifted = &'tcx BareFnTy<'tcx>; fn lift_to_tcx<'b, 'gcx>(&self, tcx: TyCtxt<'b, 'gcx, 'tcx>) -> Option<&'tcx BareFnTy<'tcx>> { if let Some(&Interned(fty)) = tcx.interners.bare_fn.borrow().get(*self) { if *self as *const _ == fty as *const _ { return Some(fty); } } // Also try in the global tcx if we're not that. if !tcx.is_global() { self.lift_to_tcx(tcx.global_tcx()) } else { None } } } pub mod tls { use super::{CtxtInterners, GlobalCtxt, TyCtxt}; use std::cell::Cell; use std::fmt; use syntax::codemap; /// Marker types used for the scoped TLS slot. /// The type context cannot be used directly because the scoped TLS /// in libstd doesn't allow types generic over lifetimes. enum ThreadLocalGlobalCtxt {} enum ThreadLocalInterners {} thread_local! { static TLS_TCX: Cell> = Cell::new(None) } fn span_debug(span: codemap::Span, f: &mut fmt::Formatter) -> fmt::Result { with(|tcx| { write!(f, "{}", tcx.sess.codemap().span_to_string(span)) }) } pub fn enter_global<'gcx, F, R>(gcx: GlobalCtxt<'gcx>, f: F) -> R where F: for<'a> FnOnce(TyCtxt<'a, 'gcx, 'gcx>) -> R { codemap::SPAN_DEBUG.with(|span_dbg| { let original_span_debug = span_dbg.get(); span_dbg.set(span_debug); let result = enter(&gcx, &gcx.global_interners, f); span_dbg.set(original_span_debug); result }) } pub fn enter<'a, 'gcx: 'tcx, 'tcx, F, R>(gcx: &'a GlobalCtxt<'gcx>, interners: &'a CtxtInterners<'tcx>, f: F) -> R where F: FnOnce(TyCtxt<'a, 'gcx, 'tcx>) -> R { let gcx_ptr = gcx as *const _ as *const ThreadLocalGlobalCtxt; let interners_ptr = interners as *const _ as *const ThreadLocalInterners; TLS_TCX.with(|tls| { let prev = tls.get(); tls.set(Some((gcx_ptr, interners_ptr))); let ret = f(TyCtxt { gcx: gcx, interners: interners }); tls.set(prev); ret }) } pub fn with(f: F) -> R where F: for<'a, 'gcx, 'tcx> FnOnce(TyCtxt<'a, 'gcx, 'tcx>) -> R { TLS_TCX.with(|tcx| { let (gcx, interners) = tcx.get().unwrap(); let gcx = unsafe { &*(gcx as *const GlobalCtxt) }; let interners = unsafe { &*(interners as *const CtxtInterners) }; f(TyCtxt { gcx: gcx, interners: interners }) }) } pub fn with_opt(f: F) -> R where F: for<'a, 'gcx, 'tcx> FnOnce(Option>) -> R { if TLS_TCX.with(|tcx| tcx.get().is_some()) { with(|v| f(Some(v))) } else { f(None) } } } macro_rules! sty_debug_print { ($ctxt: expr, $($variant: ident),*) => {{ // curious inner module to allow variant names to be used as // variable names. #[allow(non_snake_case)] mod inner { use ty::{self, TyCtxt}; use ty::context::Interned; #[derive(Copy, Clone)] struct DebugStat { total: usize, region_infer: usize, ty_infer: usize, both_infer: usize, } pub fn go(tcx: TyCtxt) { let mut total = DebugStat { total: 0, region_infer: 0, ty_infer: 0, both_infer: 0, }; $(let mut $variant = total;)* for &Interned(t) in tcx.interners.type_.borrow().iter() { let variant = match t.sty { ty::TyBool | ty::TyChar | ty::TyInt(..) | ty::TyUint(..) | ty::TyFloat(..) | ty::TyStr => continue, ty::TyError => /* unimportant */ continue, $(ty::$variant(..) => &mut $variant,)* }; let region = t.flags.get().intersects(ty::TypeFlags::HAS_RE_INFER); let ty = t.flags.get().intersects(ty::TypeFlags::HAS_TY_INFER); variant.total += 1; total.total += 1; if region { total.region_infer += 1; variant.region_infer += 1 } if ty { total.ty_infer += 1; variant.ty_infer += 1 } if region && ty { total.both_infer += 1; variant.both_infer += 1 } } println!("Ty interner total ty region both"); $(println!(" {:18}: {uses:6} {usespc:4.1}%, \ {ty:4.1}% {region:5.1}% {both:4.1}%", stringify!($variant), uses = $variant.total, usespc = $variant.total as f64 * 100.0 / total.total as f64, ty = $variant.ty_infer as f64 * 100.0 / total.total as f64, region = $variant.region_infer as f64 * 100.0 / total.total as f64, both = $variant.both_infer as f64 * 100.0 / total.total as f64); )* println!(" total {uses:6} \ {ty:4.1}% {region:5.1}% {both:4.1}%", uses = total.total, ty = total.ty_infer as f64 * 100.0 / total.total as f64, region = total.region_infer as f64 * 100.0 / total.total as f64, both = total.both_infer as f64 * 100.0 / total.total as f64) } } inner::go($ctxt) }} } impl<'a, 'tcx> TyCtxt<'a, 'tcx, 'tcx> { pub fn print_debug_stats(self) { sty_debug_print!( self, TyEnum, TyBox, TyArray, TySlice, TyRawPtr, TyRef, TyFnDef, TyFnPtr, TyTrait, TyStruct, TyClosure, TyTuple, TyParam, TyInfer, TyProjection); println!("Substs interner: #{}", self.interners.substs.borrow().len()); println!("BareFnTy interner: #{}", self.interners.bare_fn.borrow().len()); println!("Region interner: #{}", self.interners.region.borrow().len()); println!("Stability interner: #{}", self.interners.stability.borrow().len()); println!("Layout interner: #{}", self.interners.layout.borrow().len()); } } /// An entry in an interner. struct Interned<'tcx, T: 'tcx+?Sized>(&'tcx T); // NB: An Interned compares and hashes as a sty. impl<'tcx> PartialEq for Interned<'tcx, TyS<'tcx>> { fn eq(&self, other: &Interned<'tcx, TyS<'tcx>>) -> bool { self.0.sty == other.0.sty } } impl<'tcx> Eq for Interned<'tcx, TyS<'tcx>> {} impl<'tcx> Hash for Interned<'tcx, TyS<'tcx>> { fn hash(&self, s: &mut H) { self.0.sty.hash(s) } } impl<'tcx: 'lcx, 'lcx> Borrow> for Interned<'tcx, TyS<'tcx>> { fn borrow<'a>(&'a self) -> &'a TypeVariants<'lcx> { &self.0.sty } } impl<'tcx: 'lcx, 'lcx> Borrow<[Ty<'lcx>]> for Interned<'tcx, [Ty<'tcx>]> { fn borrow<'a>(&'a self) -> &'a [Ty<'lcx>] { self.0 } } impl<'tcx: 'lcx, 'lcx> Borrow> for Interned<'tcx, Substs<'tcx>> { fn borrow<'a>(&'a self) -> &'a Substs<'lcx> { self.0 } } impl<'tcx: 'lcx, 'lcx> Borrow> for Interned<'tcx, BareFnTy<'tcx>> { fn borrow<'a>(&'a self) -> &'a BareFnTy<'lcx> { self.0 } } impl<'tcx> Borrow for Interned<'tcx, Region> { fn borrow<'a>(&'a self) -> &'a Region { self.0 } } macro_rules! items { ($($item:item)+) => ($($item)+) } macro_rules! impl_interners { ($lt_tcx:tt, $($name:ident: $method:ident($alloc:ty, $needs_infer:expr)-> $ty:ty),+) => { items!($(impl<$lt_tcx> PartialEq for Interned<$lt_tcx, $ty> { fn eq(&self, other: &Self) -> bool { self.0 == other.0 } } impl<$lt_tcx> Eq for Interned<$lt_tcx, $ty> {} impl<$lt_tcx> Hash for Interned<$lt_tcx, $ty> { fn hash(&self, s: &mut H) { self.0.hash(s) } } impl<'a, 'gcx, $lt_tcx> TyCtxt<'a, 'gcx, $lt_tcx> { pub fn $method(self, v: $alloc) -> &$lt_tcx $ty { if let Some(i) = self.interners.$name.borrow().get::<$ty>(&v) { return i.0; } if !self.is_global() { if let Some(i) = self.global_interners.$name.borrow().get::<$ty>(&v) { return i.0; } } // HACK(eddyb) Depend on flags being accurate to // determine that all contents are in the global tcx. // See comments on Lift for why we can't use that. if !($needs_infer)(&v) { if !self.is_global() { let v = unsafe { mem::transmute(v) }; let i = self.global_interners.arenas.$name.alloc(v); self.global_interners.$name.borrow_mut().insert(Interned(i)); return i; } } else { // Make sure we don't end up with inference // types/regions in the global tcx. if self.is_global() { bug!("Attempted to intern `{:?}` which contains \ inference types/regions in the global type context", v); } } let i = self.interners.arenas.$name.alloc(v); self.interners.$name.borrow_mut().insert(Interned(i)); i } })+); } } fn keep_local<'tcx, T: ty::TypeFoldable<'tcx>>(x: &T) -> bool { x.has_type_flags(ty::TypeFlags::KEEP_IN_LOCAL_TCX) } impl_interners!('tcx, type_list: mk_type_list(Vec>, keep_local) -> [Ty<'tcx>], substs: mk_substs(Substs<'tcx>, |substs: &Substs| { keep_local(&substs.types) || keep_local(&substs.regions) }) -> Substs<'tcx>, bare_fn: mk_bare_fn(BareFnTy<'tcx>, |fty: &BareFnTy| { keep_local(&fty.sig) }) -> BareFnTy<'tcx>, region: mk_region(Region, keep_local) -> Region ); fn bound_list_is_sorted(bounds: &[ty::PolyProjectionPredicate]) -> bool { bounds.is_empty() || bounds[1..].iter().enumerate().all( |(index, bound)| bounds[index].sort_key() <= bound.sort_key()) } impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> { /// Create an unsafe fn ty based on a safe fn ty. pub fn safe_to_unsafe_fn_ty(self, bare_fn: &BareFnTy<'tcx>) -> Ty<'tcx> { assert_eq!(bare_fn.unsafety, hir::Unsafety::Normal); self.mk_fn_ptr(self.mk_bare_fn(ty::BareFnTy { unsafety: hir::Unsafety::Unsafe, abi: bare_fn.abi, sig: bare_fn.sig.clone() })) } // Interns a type/name combination, stores the resulting box in cx.interners, // and returns the box as cast to an unsafe ptr (see comments for Ty above). pub fn mk_ty(self, st: TypeVariants<'tcx>) -> Ty<'tcx> { let global_interners = if !self.is_global() { Some(&self.global_interners) } else { None }; self.interners.intern_ty(st, global_interners) } pub fn mk_mach_int(self, tm: ast::IntTy) -> Ty<'tcx> { match tm { ast::IntTy::Is => self.types.isize, ast::IntTy::I8 => self.types.i8, ast::IntTy::I16 => self.types.i16, ast::IntTy::I32 => self.types.i32, ast::IntTy::I64 => self.types.i64, } } pub fn mk_mach_uint(self, tm: ast::UintTy) -> Ty<'tcx> { match tm { ast::UintTy::Us => self.types.usize, ast::UintTy::U8 => self.types.u8, ast::UintTy::U16 => self.types.u16, ast::UintTy::U32 => self.types.u32, ast::UintTy::U64 => self.types.u64, } } pub fn mk_mach_float(self, tm: ast::FloatTy) -> Ty<'tcx> { match tm { ast::FloatTy::F32 => self.types.f32, ast::FloatTy::F64 => self.types.f64, } } pub fn mk_str(self) -> Ty<'tcx> { self.mk_ty(TyStr) } pub fn mk_static_str(self) -> Ty<'tcx> { self.mk_imm_ref(self.mk_region(ty::ReStatic), self.mk_str()) } pub fn mk_enum(self, def: AdtDef<'tcx>, substs: &'tcx Substs<'tcx>) -> Ty<'tcx> { // take a copy of substs so that we own the vectors inside self.mk_ty(TyEnum(def, substs)) } pub fn mk_box(self, ty: Ty<'tcx>) -> Ty<'tcx> { self.mk_ty(TyBox(ty)) } pub fn mk_ptr(self, tm: TypeAndMut<'tcx>) -> Ty<'tcx> { self.mk_ty(TyRawPtr(tm)) } pub fn mk_ref(self, r: &'tcx Region, tm: TypeAndMut<'tcx>) -> Ty<'tcx> { self.mk_ty(TyRef(r, tm)) } pub fn mk_mut_ref(self, r: &'tcx Region, ty: Ty<'tcx>) -> Ty<'tcx> { self.mk_ref(r, TypeAndMut {ty: ty, mutbl: hir::MutMutable}) } pub fn mk_imm_ref(self, r: &'tcx Region, ty: Ty<'tcx>) -> Ty<'tcx> { self.mk_ref(r, TypeAndMut {ty: ty, mutbl: hir::MutImmutable}) } pub fn mk_mut_ptr(self, ty: Ty<'tcx>) -> Ty<'tcx> { self.mk_ptr(TypeAndMut {ty: ty, mutbl: hir::MutMutable}) } pub fn mk_imm_ptr(self, ty: Ty<'tcx>) -> Ty<'tcx> { self.mk_ptr(TypeAndMut {ty: ty, mutbl: hir::MutImmutable}) } pub fn mk_nil_ptr(self) -> Ty<'tcx> { self.mk_imm_ptr(self.mk_nil()) } pub fn mk_array(self, ty: Ty<'tcx>, n: usize) -> Ty<'tcx> { self.mk_ty(TyArray(ty, n)) } pub fn mk_slice(self, ty: Ty<'tcx>) -> Ty<'tcx> { self.mk_ty(TySlice(ty)) } pub fn mk_tup(self, ts: Vec>) -> Ty<'tcx> { self.mk_ty(TyTuple(self.mk_type_list(ts))) } pub fn mk_nil(self) -> Ty<'tcx> { self.mk_tup(Vec::new()) } pub fn mk_bool(self) -> Ty<'tcx> { self.mk_ty(TyBool) } pub fn mk_fn_def(self, def_id: DefId, substs: &'tcx Substs<'tcx>, fty: &'tcx BareFnTy<'tcx>) -> Ty<'tcx> { self.mk_ty(TyFnDef(def_id, substs, fty)) } pub fn mk_fn_ptr(self, fty: &'tcx BareFnTy<'tcx>) -> Ty<'tcx> { self.mk_ty(TyFnPtr(fty)) } pub fn mk_trait(self, principal: ty::PolyTraitRef<'tcx>, bounds: ExistentialBounds<'tcx>) -> Ty<'tcx> { assert!(bound_list_is_sorted(&bounds.projection_bounds)); let inner = box TraitTy { principal: principal, bounds: bounds }; self.mk_ty(TyTrait(inner)) } pub fn mk_projection(self, trait_ref: TraitRef<'tcx>, item_name: Name) -> Ty<'tcx> { // take a copy of substs so that we own the vectors inside let inner = ProjectionTy { trait_ref: trait_ref, item_name: item_name }; self.mk_ty(TyProjection(inner)) } pub fn mk_struct(self, def: AdtDef<'tcx>, substs: &'tcx Substs<'tcx>) -> Ty<'tcx> { // take a copy of substs so that we own the vectors inside self.mk_ty(TyStruct(def, substs)) } pub fn mk_closure(self, closure_id: DefId, substs: &'tcx Substs<'tcx>, tys: Vec>) -> Ty<'tcx> { self.mk_closure_from_closure_substs(closure_id, ClosureSubsts { func_substs: substs, upvar_tys: self.mk_type_list(tys) }) } pub fn mk_closure_from_closure_substs(self, closure_id: DefId, closure_substs: ClosureSubsts<'tcx>) -> Ty<'tcx> { self.mk_ty(TyClosure(closure_id, closure_substs)) } pub fn mk_var(self, v: TyVid) -> Ty<'tcx> { self.mk_infer(TyVar(v)) } pub fn mk_int_var(self, v: IntVid) -> Ty<'tcx> { self.mk_infer(IntVar(v)) } pub fn mk_float_var(self, v: FloatVid) -> Ty<'tcx> { self.mk_infer(FloatVar(v)) } pub fn mk_infer(self, it: InferTy) -> Ty<'tcx> { self.mk_ty(TyInfer(it)) } pub fn mk_param(self, space: subst::ParamSpace, index: u32, name: Name) -> Ty<'tcx> { self.mk_ty(TyParam(ParamTy { space: space, idx: index, name: name })) } pub fn mk_self_type(self) -> Ty<'tcx> { self.mk_param(subst::SelfSpace, 0, keywords::SelfType.name()) } pub fn mk_param_from_def(self, def: &ty::TypeParameterDef) -> Ty<'tcx> { self.mk_param(def.space, def.index, def.name) } pub fn trait_items(self, trait_did: DefId) -> Rc>> { self.trait_items_cache.memoize(trait_did, || { let def_ids = self.trait_item_def_ids(trait_did); Rc::new(def_ids.iter() .map(|d| self.impl_or_trait_item(d.def_id())) .collect()) }) } /// Obtain the representation annotation for a struct definition. pub fn lookup_repr_hints(self, did: DefId) -> Rc> { self.repr_hint_cache.memoize(did, || { Rc::new(if did.is_local() { self.get_attrs(did).iter().flat_map(|meta| { attr::find_repr_attrs(self.sess.diagnostic(), meta).into_iter() }).collect() } else { self.sess.cstore.repr_attrs(did) }) }) } }