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chromium / external / github.com / rust-lang / rust / 56290a004493a5d2e211f056601533253497df60 / . / src / librustc / middle / ty.rs
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// Copyright 2012-2014 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 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
#![allow(non_camel_case_types)]
pub use self::terr_vstore_kind::*;
pub use self::type_err::*;
pub use self::BuiltinBound::*;
pub use self::InferTy::*;
pub use self::InferRegion::*;
pub use self::ImplOrTraitItemId::*;
pub use self::UnboxedClosureKind::*;
pub use self::TraitStore::*;
pub use self::ast_ty_to_ty_cache_entry::*;
pub use self::Variance::*;
pub use self::AutoAdjustment::*;
pub use self::Representability::*;
pub use self::UnsizeKind::*;
pub use self::AutoRef::*;
pub use self::ExprKind::*;
pub use self::DtorKind::*;
pub use self::ExplicitSelfCategory::*;
pub use self::FnOutput::*;
pub use self::Region::*;
pub use self::ImplOrTraitItemContainer::*;
pub use self::BorrowKind::*;
pub use self::ImplOrTraitItem::*;
pub use self::BoundRegion::*;
pub use self::sty::*;
pub use self::IntVarValue::*;
pub use self::ExprAdjustment::*;
pub use self::vtable_origin::*;
pub use self::MethodOrigin::*;
pub use self::CopyImplementationError::*;
use back::svh::Svh;
use session::Session;
use lint;
use metadata::csearch;
use middle;
use middle::const_eval;
use middle::def::{mod, DefMap, ExportMap};
use middle::dependency_format;
use middle::lang_items::{FnTraitLangItem, FnMutTraitLangItem};
use middle::lang_items::{FnOnceTraitLangItem, TyDescStructLangItem};
use middle::mem_categorization as mc;
use middle::region;
use middle::resolve_lifetime;
use middle::infer;
use middle::stability;
use middle::subst::{mod, Subst, Substs, VecPerParamSpace};
use middle::traits;
use middle::ty;
use middle::ty_fold::{mod, TypeFoldable, TypeFolder};
use util::ppaux::{note_and_explain_region, bound_region_ptr_to_string};
use util::ppaux::{trait_store_to_string, ty_to_string};
use util::ppaux::{Repr, UserString};
use util::common::{memoized, ErrorReported};
use util::nodemap::{NodeMap, NodeSet, DefIdMap, DefIdSet};
use util::nodemap::{FnvHashMap};
use arena::TypedArena;
use std::borrow::BorrowFrom;
use std::cell::{Cell, RefCell};
use std::cmp::{mod, Ordering};
use std::fmt::{mod, Show};
use std::hash::{Hash, sip, Writer};
use std::mem;
use std::ops;
use std::rc::Rc;
use collections::enum_set::{EnumSet, CLike};
use std::collections::{HashMap, HashSet};
use std::collections::hash_map::Entry::{Occupied, Vacant};
use syntax::abi;
use syntax::ast::{CrateNum, DefId, Ident, ItemTrait, LOCAL_CRATE};
use syntax::ast::{MutImmutable, MutMutable, Name, NamedField, NodeId};
use syntax::ast::{Onceness, StmtExpr, StmtSemi, StructField, UnnamedField};
use syntax::ast::{Visibility};
use syntax::ast_util::{mod, is_local, lit_is_str, local_def, PostExpansionMethod};
use syntax::attr::{mod, AttrMetaMethods};
use syntax::codemap::Span;
use syntax::parse::token::{mod, InternedString, special_idents};
use syntax::{ast, ast_map};
pub type Disr = u64;
pub const INITIAL_DISCRIMINANT_VALUE: Disr = 0;
// Data types
/// The complete set of all analyses described in this module. This is
/// produced by the driver and fed to trans and later passes.
pub struct CrateAnalysis<'tcx> {
pub export_map: ExportMap,
pub exported_items: middle::privacy::ExportedItems,
pub public_items: middle::privacy::PublicItems,
pub ty_cx: ty::ctxt<'tcx>,
pub reachable: NodeSet,
pub name: String,
pub glob_map: Option<GlobMap>,
}
#[deriving(Copy, PartialEq, Eq, Hash)]
pub struct field<'tcx> {
pub name: ast::Name,
pub mt: mt<'tcx>
}
#[deriving(Clone, Copy, Show)]
pub enum ImplOrTraitItemContainer {
TraitContainer(ast::DefId),
ImplContainer(ast::DefId),
}
impl ImplOrTraitItemContainer {
pub fn id(&self) -> ast::DefId {
match *self {
TraitContainer(id) => id,
ImplContainer(id) => id,
}
}
}
#[deriving(Clone)]
pub enum ImplOrTraitItem<'tcx> {
MethodTraitItem(Rc<Method<'tcx>>),
TypeTraitItem(Rc<AssociatedType>),
}
impl<'tcx> ImplOrTraitItem<'tcx> {
fn id(&self) -> ImplOrTraitItemId {
match *self {
MethodTraitItem(ref method) => MethodTraitItemId(method.def_id),
TypeTraitItem(ref associated_type) => {
TypeTraitItemId(associated_type.def_id)
}
}
}
pub fn def_id(&self) -> ast::DefId {
match *self {
MethodTraitItem(ref method) => method.def_id,
TypeTraitItem(ref associated_type) => associated_type.def_id,
}
}
pub fn name(&self) -> ast::Name {
match *self {
MethodTraitItem(ref method) => method.name,
TypeTraitItem(ref associated_type) => associated_type.name,
}
}
pub fn container(&self) -> ImplOrTraitItemContainer {
match *self {
MethodTraitItem(ref method) => method.container,
TypeTraitItem(ref associated_type) => associated_type.container,
}
}
pub fn as_opt_method(&self) -> Option<Rc<Method<'tcx>>> {
match *self {
MethodTraitItem(ref m) => Some((*m).clone()),
TypeTraitItem(_) => None
}
}
}
#[deriving(Clone, Copy)]
pub enum ImplOrTraitItemId {
MethodTraitItemId(ast::DefId),
TypeTraitItemId(ast::DefId),
}
impl ImplOrTraitItemId {
pub fn def_id(&self) -> ast::DefId {
match *self {
MethodTraitItemId(def_id) => def_id,
TypeTraitItemId(def_id) => def_id,
}
}
}
#[deriving(Clone, Show)]
pub struct Method<'tcx> {
pub name: ast::Name,
pub generics: ty::Generics<'tcx>,
pub fty: BareFnTy<'tcx>,
pub explicit_self: ExplicitSelfCategory,
pub vis: ast::Visibility,
pub def_id: ast::DefId,
pub container: ImplOrTraitItemContainer,
// If this method is provided, we need to know where it came from
pub provided_source: Option<ast::DefId>
}
impl<'tcx> Method<'tcx> {
pub fn new(name: ast::Name,
generics: ty::Generics<'tcx>,
fty: BareFnTy<'tcx>,
explicit_self: ExplicitSelfCategory,
vis: ast::Visibility,
def_id: ast::DefId,
container: ImplOrTraitItemContainer,
provided_source: Option<ast::DefId>)
-> Method<'tcx> {
Method {
name: name,
generics: generics,
fty: fty,
explicit_self: explicit_self,
vis: vis,
def_id: def_id,
container: container,
provided_source: provided_source
}
}
pub fn container_id(&self) -> ast::DefId {
match self.container {
TraitContainer(id) => id,
ImplContainer(id) => id,
}
}
}
#[deriving(Clone, Copy)]
pub struct AssociatedType {
pub name: ast::Name,
pub vis: ast::Visibility,
pub def_id: ast::DefId,
pub container: ImplOrTraitItemContainer,
}
#[deriving(Clone, Copy, PartialEq, Eq, Hash, Show)]
pub struct mt<'tcx> {
pub ty: Ty<'tcx>,
pub mutbl: ast::Mutability,
}
#[deriving(Clone, Copy, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, Show)]
pub enum TraitStore {
/// Box<Trait>
UniqTraitStore,
/// &Trait and &mut Trait
RegionTraitStore(Region, ast::Mutability),
}
#[deriving(Clone, Copy, Show)]
pub struct field_ty {
pub name: Name,
pub id: DefId,
pub vis: ast::Visibility,
pub origin: ast::DefId, // The DefId of the struct in which the field is declared.
}
// Contains information needed to resolve types and (in the future) look up
// the types of AST nodes.
#[deriving(Copy, PartialEq, Eq, Hash)]
pub struct creader_cache_key {
pub cnum: CrateNum,
pub pos: uint,
pub len: uint
}
#[deriving(Copy)]
pub enum ast_ty_to_ty_cache_entry<'tcx> {
atttce_unresolved, /* not resolved yet */
atttce_resolved(Ty<'tcx>) /* resolved to a type, irrespective of region */
}
#[deriving(Clone, PartialEq, RustcDecodable, RustcEncodable)]
pub struct ItemVariances {
pub types: VecPerParamSpace<Variance>,
pub regions: VecPerParamSpace<Variance>,
}
#[deriving(Clone, PartialEq, RustcDecodable, RustcEncodable, Show, Copy)]
pub enum Variance {
Covariant, // T<A> <: T<B> iff A <: B -- e.g., function return type
Invariant, // T<A> <: T<B> iff B == A -- e.g., type of mutable cell
Contravariant, // T<A> <: T<B> iff B <: A -- e.g., function param type
Bivariant, // T<A> <: T<B> -- e.g., unused type parameter
}
#[deriving(Clone, Show)]
pub enum AutoAdjustment<'tcx> {
AdjustAddEnv(ast::DefId, ty::TraitStore),
AdjustReifyFnPointer(ast::DefId), // go from a fn-item type to a fn-pointer type
AdjustDerefRef(AutoDerefRef<'tcx>)
}
#[deriving(Clone, PartialEq, Show)]
pub enum UnsizeKind<'tcx> {
// [T, ..n] -> [T], the uint field is n.
UnsizeLength(uint),
// An unsize coercion applied to the tail field of a struct.
// The uint is the index of the type parameter which is unsized.
UnsizeStruct(Box<UnsizeKind<'tcx>>, uint),
UnsizeVtable(TyTrait<'tcx>, /* the self type of the trait */ Ty<'tcx>)
}
#[deriving(Clone, Show)]
pub struct AutoDerefRef<'tcx> {
pub autoderefs: uint,
pub autoref: Option<AutoRef<'tcx>>
}
#[deriving(Clone, PartialEq, Show)]
pub enum AutoRef<'tcx> {
/// Convert from T to &T
/// The third field allows us to wrap other AutoRef adjustments.
AutoPtr(Region, ast::Mutability, Option<Box<AutoRef<'tcx>>>),
/// Convert [T, ..n] to [T] (or similar, depending on the kind)
AutoUnsize(UnsizeKind<'tcx>),
/// Convert Box<[T, ..n]> to Box<[T]> or something similar in a Box.
/// With DST and Box a library type, this should be replaced by UnsizeStruct.
AutoUnsizeUniq(UnsizeKind<'tcx>),
/// Convert from T to *T
/// Value to thin pointer
/// The second field allows us to wrap other AutoRef adjustments.
AutoUnsafe(ast::Mutability, Option<Box<AutoRef<'tcx>>>),
}
// Ugly little helper function. The first bool in the returned tuple is true if
// there is an 'unsize to trait object' adjustment at the bottom of the
// adjustment. If that is surrounded by an AutoPtr, then we also return the
// region of the AutoPtr (in the third argument). The second bool is true if the
// adjustment is unique.
fn autoref_object_region(autoref: &AutoRef) -> (bool, bool, Option<Region>) {
fn unsize_kind_is_object(k: &UnsizeKind) -> bool {
match k {
&UnsizeVtable(..) => true,
&UnsizeStruct(box ref k, _) => unsize_kind_is_object(k),
_ => false
}
}
match autoref {
&AutoUnsize(ref k) => (unsize_kind_is_object(k), false, None),
&AutoUnsizeUniq(ref k) => (unsize_kind_is_object(k), true, None),
&AutoPtr(adj_r, _, Some(box ref autoref)) => {
let (b, u, r) = autoref_object_region(autoref);
if r.is_some() || u {
(b, u, r)
} else {
(b, u, Some(adj_r))
}
}
&AutoUnsafe(_, Some(box ref autoref)) => autoref_object_region(autoref),
_ => (false, false, None)
}
}
// If the adjustment introduces a borrowed reference to a trait object, then
// returns the region of the borrowed reference.
pub fn adjusted_object_region(adj: &AutoAdjustment) -> Option<Region> {
match adj {
&AdjustDerefRef(AutoDerefRef{autoref: Some(ref autoref), ..}) => {
let (b, _, r) = autoref_object_region(autoref);
if b {
r
} else {
None
}
}
_ => None
}
}
// Returns true if there is a trait cast at the bottom of the adjustment.
pub fn adjust_is_object(adj: &AutoAdjustment) -> bool {
match adj {
&AdjustDerefRef(AutoDerefRef{autoref: Some(ref autoref), ..}) => {
let (b, _, _) = autoref_object_region(autoref);
b
}
_ => false
}
}
// If possible, returns the type expected from the given adjustment. This is not
// possible if the adjustment depends on the type of the adjusted expression.
pub fn type_of_adjust<'tcx>(cx: &ctxt<'tcx>, adj: &AutoAdjustment<'tcx>) -> Option<Ty<'tcx>> {
fn type_of_autoref<'tcx>(cx: &ctxt<'tcx>, autoref: &AutoRef<'tcx>) -> Option<Ty<'tcx>> {
match autoref {
&AutoUnsize(ref k) => match k {
&UnsizeVtable(TyTrait { ref principal, ref bounds }, _) => {
Some(mk_trait(cx, principal.clone(), bounds.clone()))
}
_ => None
},
&AutoUnsizeUniq(ref k) => match k {
&UnsizeVtable(TyTrait { ref principal, ref bounds }, _) => {
Some(mk_uniq(cx, mk_trait(cx, principal.clone(), bounds.clone())))
}
_ => None
},
&AutoPtr(r, m, Some(box ref autoref)) => {
match type_of_autoref(cx, autoref) {
Some(ty) => Some(mk_rptr(cx, cx.mk_region(r), mt {mutbl: m, ty: ty})),
None => None
}
}
&AutoUnsafe(m, Some(box ref autoref)) => {
match type_of_autoref(cx, autoref) {
Some(ty) => Some(mk_ptr(cx, mt {mutbl: m, ty: ty})),
None => None
}
}
_ => None
}
}
match adj {
&AdjustDerefRef(AutoDerefRef{autoref: Some(ref autoref), ..}) => {
type_of_autoref(cx, autoref)
}
_ => None
}
}
#[deriving(Clone, Copy, RustcEncodable, RustcDecodable, PartialEq, PartialOrd, Show)]
pub struct param_index {
pub space: subst::ParamSpace,
pub index: uint
}
#[deriving(Clone, Show)]
pub enum MethodOrigin<'tcx> {
// fully statically resolved method
MethodStatic(ast::DefId),
// fully statically resolved unboxed closure invocation
MethodStaticUnboxedClosure(ast::DefId),
// method invoked on a type parameter with a bounded trait
MethodTypeParam(MethodParam<'tcx>),
// method invoked on a trait instance
MethodTraitObject(MethodObject<'tcx>),
}
// details for a method invoked with a receiver whose type is a type parameter
// with a bounded trait.
#[deriving(Clone, Show)]
pub struct MethodParam<'tcx> {
// the precise trait reference that occurs as a bound -- this may
// be a supertrait of what the user actually typed. Note that it
// never contains bound regions; those regions should have been
// instantiated with fresh variables at this point.
pub trait_ref: Rc<ty::TraitRef<'tcx>>,
// index of uint in the list of methods for the trait
pub method_num: uint,
}
// details for a method invoked with a receiver whose type is an object
#[deriving(Clone, Show)]
pub struct MethodObject<'tcx> {
// the (super)trait containing the method to be invoked
pub trait_ref: Rc<ty::TraitRef<'tcx>>,
// the actual base trait id of the object
pub object_trait_id: ast::DefId,
// index of the method to be invoked amongst the trait's methods
pub method_num: uint,
// index into the actual runtime vtable.
// the vtable is formed by concatenating together the method lists of
// the base object trait and all supertraits; this is the index into
// that vtable
pub real_index: uint,
}
#[deriving(Clone)]
pub struct MethodCallee<'tcx> {
pub origin: MethodOrigin<'tcx>,
pub ty: Ty<'tcx>,
pub substs: subst::Substs<'tcx>
}
/// With method calls, we store some extra information in
/// side tables (i.e method_map). We use
/// MethodCall as a key to index into these tables instead of
/// just directly using the expression's NodeId. The reason
/// for this being that we may apply adjustments (coercions)
/// with the resulting expression also needing to use the
/// side tables. The problem with this is that we don't
/// assign a separate NodeId to this new expression
/// and so it would clash with the base expression if both
/// needed to add to the side tables. Thus to disambiguate
/// we also keep track of whether there's an adjustment in
/// our key.
#[deriving(Clone, Copy, PartialEq, Eq, Hash, Show)]
pub struct MethodCall {
pub expr_id: ast::NodeId,
pub adjustment: ExprAdjustment
}
#[deriving(Clone, PartialEq, Eq, Hash, Show, RustcEncodable, RustcDecodable, Copy)]
pub enum ExprAdjustment {
NoAdjustment,
AutoDeref(uint),
AutoObject
}
impl MethodCall {
pub fn expr(id: ast::NodeId) -> MethodCall {
MethodCall {
expr_id: id,
adjustment: NoAdjustment
}
}
pub fn autoobject(id: ast::NodeId) -> MethodCall {
MethodCall {
expr_id: id,
adjustment: AutoObject
}
}
pub fn autoderef(expr_id: ast::NodeId, autoderef: uint) -> MethodCall {
MethodCall {
expr_id: expr_id,
adjustment: AutoDeref(1 + autoderef)
}
}
}
// maps from an expression id that corresponds to a method call to the details
// of the method to be invoked
pub type MethodMap<'tcx> = RefCell<FnvHashMap<MethodCall, MethodCallee<'tcx>>>;
pub type vtable_param_res<'tcx> = Vec<vtable_origin<'tcx>>;
// Resolutions for bounds of all parameters, left to right, for a given path.
pub type vtable_res<'tcx> = VecPerParamSpace<vtable_param_res<'tcx>>;
#[deriving(Clone)]
pub enum vtable_origin<'tcx> {
/*
Statically known vtable. def_id gives the impl item
from whence comes the vtable, and tys are the type substs.
vtable_res is the vtable itself.
*/
vtable_static(ast::DefId, subst::Substs<'tcx>, vtable_res<'tcx>),
/*
Dynamic vtable, comes from a parameter that has a bound on it:
fn foo<T:quux,baz,bar>(a: T) -- a's vtable would have a
vtable_param origin
The first argument is the param index (identifying T in the example),
and the second is the bound number (identifying baz)
*/
vtable_param(param_index, uint),
/*
Vtable automatically generated for an unboxed closure. The def ID is the
ID of the closure expression.
*/
vtable_unboxed_closure(ast::DefId),
/*
Asked to determine the vtable for ty_err. This is the value used
for the vtables of `Self` in a virtual call like `foo.bar()`
where `foo` is of object type. The same value is also used when
type errors occur.
*/
vtable_error,
}
// For every explicit cast into an object type, maps from the cast
// expr to the associated trait ref.
pub type ObjectCastMap<'tcx> = RefCell<NodeMap<ty::PolyTraitRef<'tcx>>>;
/// A restriction that certain types must be the same size. The use of
/// `transmute` gives rise to these restrictions. These generally
/// cannot be checked until trans; therefore, each call to `transmute`
/// will push one or more such restriction into the
/// `transmute_restrictions` vector during `intrinsicck`. They are
/// then checked during `trans` by the fn `check_intrinsics`.
#[deriving(Copy)]
pub struct TransmuteRestriction<'tcx> {
/// The span whence the restriction comes.
pub span: Span,
/// The type being transmuted from.
pub original_from: Ty<'tcx>,
/// The type being transmuted to.
pub original_to: Ty<'tcx>,
/// The type being transmuted from, with all type parameters
/// substituted for an arbitrary representative. Not to be shown
/// to the end user.
pub substituted_from: Ty<'tcx>,
/// The type being transmuted to, with all type parameters
/// substituted for an arbitrary representative. Not to be shown
/// to the end user.
pub substituted_to: Ty<'tcx>,
/// NodeId of the transmute intrinsic.
pub id: ast::NodeId,
}
/// Internal storage
pub struct CtxtArenas<'tcx> {
type_: TypedArena<TyS<'tcx>>,
substs: TypedArena<Substs<'tcx>>,
bare_fn: TypedArena<BareFnTy<'tcx>>,
region: TypedArena<Region>,
}
impl<'tcx> CtxtArenas<'tcx> {
pub fn new() -> CtxtArenas<'tcx> {
CtxtArenas {
type_: TypedArena::new(),
substs: TypedArena::new(),
bare_fn: TypedArena::new(),
region: TypedArena::new(),
}
}
}
pub struct CommonTypes<'tcx> {
pub bool: Ty<'tcx>,
pub char: Ty<'tcx>,
pub int: Ty<'tcx>,
pub i8: Ty<'tcx>,
pub i16: Ty<'tcx>,
pub i32: Ty<'tcx>,
pub i64: Ty<'tcx>,
pub uint: 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>,
}
/// 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.
pub struct ctxt<'tcx> {
/// The arenas that types etc are allocated from.
arenas: &'tcx CtxtArenas<'tcx>,
/// Specifically use a speedy hash algorithm for this hash map, it's used
/// quite often.
// FIXME(eddyb) use a FnvHashSet<InternedTy<'tcx>> when equivalent keys can
// queried from a HashSet.
interner: RefCell<FnvHashMap<InternedTy<'tcx>, Ty<'tcx>>>,
// FIXME as above, use a hashset if equivalent elements can be queried.
substs_interner: RefCell<FnvHashMap<&'tcx Substs<'tcx>, &'tcx Substs<'tcx>>>,
bare_fn_interner: RefCell<FnvHashMap<&'tcx BareFnTy<'tcx>, &'tcx BareFnTy<'tcx>>>,
region_interner: RefCell<FnvHashMap<&'tcx Region, &'tcx Region>>,
/// Common types, pre-interned for your convenience.
pub types: CommonTypes<'tcx>,
pub sess: Session,
pub def_map: DefMap,
pub named_region_map: resolve_lifetime::NamedRegionMap,
pub region_maps: middle::region::RegionMaps,
/// 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: RefCell<NodeMap<Ty<'tcx>>>,
/// 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: RefCell<NodeMap<ItemSubsts<'tcx>>>,
/// Maps from a trait item to the trait item "descriptor"
pub impl_or_trait_items: RefCell<DefIdMap<ImplOrTraitItem<'tcx>>>,
/// Maps from a trait def-id to a list of the def-ids of its trait items
pub trait_item_def_ids: RefCell<DefIdMap<Rc<Vec<ImplOrTraitItemId>>>>,
/// A cache for the trait_items() routine
pub trait_items_cache: RefCell<DefIdMap<Rc<Vec<ImplOrTraitItem<'tcx>>>>>,
pub impl_trait_cache: RefCell<DefIdMap<Option<Rc<ty::TraitRef<'tcx>>>>>,
pub trait_refs: RefCell<NodeMap<Rc<TraitRef<'tcx>>>>,
pub trait_defs: RefCell<DefIdMap<Rc<TraitDef<'tcx>>>>,
/// Maps from node-id of a trait object cast (like `foo as
/// Box<Trait>`) to the trait reference.
pub object_cast_map: ObjectCastMap<'tcx>,
pub map: ast_map::Map<'tcx>,
pub intrinsic_defs: RefCell<DefIdMap<Ty<'tcx>>>,
pub freevars: RefCell<FreevarMap>,
pub tcache: RefCell<DefIdMap<TypeScheme<'tcx>>>,
pub rcache: RefCell<FnvHashMap<creader_cache_key, Ty<'tcx>>>,
pub short_names_cache: RefCell<FnvHashMap<Ty<'tcx>, String>>,
pub tc_cache: RefCell<FnvHashMap<Ty<'tcx>, TypeContents>>,
pub ast_ty_to_ty_cache: RefCell<NodeMap<ast_ty_to_ty_cache_entry<'tcx>>>,
pub enum_var_cache: RefCell<DefIdMap<Rc<Vec<Rc<VariantInfo<'tcx>>>>>>,
pub ty_param_defs: RefCell<NodeMap<TypeParameterDef<'tcx>>>,
pub adjustments: RefCell<NodeMap<AutoAdjustment<'tcx>>>,
pub normalized_cache: RefCell<FnvHashMap<Ty<'tcx>, Ty<'tcx>>>,
pub lang_items: middle::lang_items::LanguageItems,
/// A mapping of fake provided method def_ids to the default implementation
pub provided_method_sources: RefCell<DefIdMap<ast::DefId>>,
pub struct_fields: RefCell<DefIdMap<Rc<Vec<field_ty>>>>,
/// Maps from def-id of a type or region parameter to its
/// (inferred) variance.
pub item_variance_map: RefCell<DefIdMap<Rc<ItemVariances>>>,
/// True if the variance has been computed yet; false otherwise.
pub variance_computed: Cell<bool>,
/// A mapping from the def ID of an enum or struct type to the def ID
/// of the method that implements its destructor. If the type is not
/// present in this map, it does not have a destructor. This map is
/// populated during the coherence phase of typechecking.
pub destructor_for_type: RefCell<DefIdMap<ast::DefId>>,
/// A method will be in this list if and only if it is a destructor.
pub destructors: RefCell<DefIdSet>,
/// Maps a trait onto a list of impls of that trait.
pub trait_impls: RefCell<DefIdMap<Rc<RefCell<Vec<ast::DefId>>>>>,
/// 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<DefIdMap<Rc<Vec<ast::DefId>>>>,
/// 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<DefIdMap<Vec<ImplOrTraitItemId>>>,
/// Set of used unsafe nodes (functions or blocks). Unsafe nodes not
/// present in this set can be warned about.
pub used_unsafe: RefCell<NodeSet>,
/// 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<NodeSet>,
/// The set of external nominal types whose implementations have been read.
/// This is used for lazy resolution of methods.
pub populated_external_types: RefCell<DefIdSet>,
/// The set of external traits whose implementations have been read. This
/// is used for lazy resolution of traits.
pub populated_external_traits: RefCell<DefIdSet>,
/// Borrows
pub upvar_borrow_map: RefCell<UpvarBorrowMap>,
/// These two caches are used by const_eval when decoding external statics
/// and variants that are found.
pub extern_const_statics: RefCell<DefIdMap<ast::NodeId>>,
pub extern_const_variants: RefCell<DefIdMap<ast::NodeId>>,
pub method_map: MethodMap<'tcx>,
pub dependency_formats: RefCell<dependency_format::Dependencies>,
/// Records the type of each unboxed closure. The def ID is the ID of the
/// expression defining the unboxed closure.
pub unboxed_closures: RefCell<DefIdMap<UnboxedClosure<'tcx>>>,
pub node_lint_levels: RefCell<FnvHashMap<(ast::NodeId, lint::LintId),
lint::LevelSource>>,
/// The types that must be asserted to be the same size for `transmute`
/// to be valid. We gather up these restrictions in the intrinsicck pass
/// and check them in trans.
pub transmute_restrictions: RefCell<Vec<TransmuteRestriction<'tcx>>>,
/// Maps any item's def-id to its stability index.
pub stability: RefCell<stability::Index>,
/// Maps closures to their capture clauses.
pub capture_modes: RefCell<CaptureModeMap>,
/// Maps def IDs to true if and only if they're associated types.
pub associated_types: RefCell<DefIdMap<bool>>,
/// 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 representation hints for struct definitions.
pub repr_hint_cache: RefCell<DefIdMap<Rc<Vec<attr::ReprAttr>>>>,
/// Caches whether types are known to impl Copy. Note that type
/// parameters are never placed into this cache, because their
/// results are dependent on the parameter environment.
pub type_impls_copy_cache: RefCell<HashMap<Ty<'tcx>,bool>>,
/// Caches whether types are known to impl Sized. Note that type
/// parameters are never placed into this cache, because their
/// results are dependent on the parameter environment.
pub type_impls_sized_cache: RefCell<HashMap<Ty<'tcx>,bool>>,
}
// Flags that we track on types. These flags are propagated upwards
// through the type during type construction, so that we can quickly
// check whether the type has various kinds of types in it without
// recursing over the type itself.
bitflags! {
flags TypeFlags: u32 {
const NO_TYPE_FLAGS = 0b0,
const HAS_PARAMS = 0b1,
const HAS_SELF = 0b10,
const HAS_TY_INFER = 0b100,
const HAS_RE_INFER = 0b1000,
const HAS_RE_LATE_BOUND = 0b10000,
const HAS_REGIONS = 0b100000,
const HAS_TY_ERR = 0b1000000,
const HAS_PROJECTION = 0b10000000,
const NEEDS_SUBST = HAS_PARAMS.bits | HAS_SELF.bits | HAS_REGIONS.bits,
}
}
macro_rules! sty_debug_print {
($ctxt: expr, $($variant: ident),*) => {{
// curious inner module to allow variant names to be used as
// variable names.
mod inner {
use middle::ty;
#[deriving(Copy)]
struct DebugStat {
total: uint,
region_infer: uint,
ty_infer: uint,
both_infer: uint,
}
pub fn go(tcx: &ty::ctxt) {
let mut total = DebugStat {
total: 0,
region_infer: 0, ty_infer: 0, both_infer: 0,
};
$(let mut $variant = total;)*
for (_, t) in tcx.interner.borrow().iter() {
let variant = match t.sty {
ty::ty_bool | ty::ty_char | ty::ty_int(..) | ty::ty_uint(..) |
ty::ty_float(..) | ty::ty_str => continue,
ty::ty_err => /* unimportant */ continue,
$(ty::$variant(..) => &mut $variant,)*
};
let region = t.flags.intersects(ty::HAS_RE_INFER);
let ty = t.flags.intersects(ty::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<'tcx> ctxt<'tcx> {
pub fn print_debug_stats(&self) {
sty_debug_print!(
self,
ty_enum, ty_uniq, ty_vec, ty_ptr, ty_rptr, ty_bare_fn, ty_closure, ty_trait,
ty_struct, ty_unboxed_closure, ty_tup, ty_param, ty_open, ty_infer, ty_projection);
println!("Substs interner: #{}", self.substs_interner.borrow().len());
println!("BareFnTy interner: #{}", self.bare_fn_interner.borrow().len());
println!("Region interner: #{}", self.region_interner.borrow().len());
}
}
#[deriving(Show)]
pub struct TyS<'tcx> {
pub sty: sty<'tcx>,
pub flags: TypeFlags,
// the maximal depth of any bound regions appearing in this type.
region_depth: u32,
}
impl fmt::Show for TypeFlags {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "{}", self.bits)
}
}
impl<'tcx> PartialEq for TyS<'tcx> {
fn eq(&self, other: &TyS<'tcx>) -> bool {
(self as *const _) == (other as *const _)
}
}
impl<'tcx> Eq for TyS<'tcx> {}
impl<'tcx, S: Writer> Hash<S> for TyS<'tcx> {
fn hash(&self, s: &mut S) {
(self as *const _).hash(s)
}
}
pub type Ty<'tcx> = &'tcx TyS<'tcx>;
/// An entry in the type interner.
pub struct InternedTy<'tcx> {
ty: Ty<'tcx>
}
// NB: An InternedTy compares and hashes as a sty.
impl<'tcx> PartialEq for InternedTy<'tcx> {
fn eq(&self, other: &InternedTy<'tcx>) -> bool {
self.ty.sty == other.ty.sty
}
}
impl<'tcx> Eq for InternedTy<'tcx> {}
impl<'tcx, S: Writer> Hash<S> for InternedTy<'tcx> {
fn hash(&self, s: &mut S) {
self.ty.sty.hash(s)
}
}
impl<'tcx> BorrowFrom<InternedTy<'tcx>> for sty<'tcx> {
fn borrow_from<'a>(ty: &'a InternedTy<'tcx>) -> &'a sty<'tcx> {
&ty.ty.sty
}
}
pub fn type_has_params(ty: Ty) -> bool {
ty.flags.intersects(HAS_PARAMS)
}
pub fn type_has_self(ty: Ty) -> bool {
ty.flags.intersects(HAS_SELF)
}
pub fn type_has_ty_infer(ty: Ty) -> bool {
ty.flags.intersects(HAS_TY_INFER)
}
pub fn type_needs_infer(ty: Ty) -> bool {
ty.flags.intersects(HAS_TY_INFER | HAS_RE_INFER)
}
pub fn type_has_projection(ty: Ty) -> bool {
ty.flags.intersects(HAS_PROJECTION)
}
pub fn type_has_late_bound_regions(ty: Ty) -> bool {
ty.flags.intersects(HAS_RE_LATE_BOUND)
}
/// An "escaping region" is a bound region whose binder is not part of `t`.
///
/// So, for example, consider a type like the following, which has two binders:
///
/// for<'a> fn(x: for<'b> fn(&'a int, &'b int))
/// ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ outer scope
/// ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ inner scope
///
/// This type has *bound regions* (`'a`, `'b`), but it does not have escaping regions, because the
/// binders of both `'a` and `'b` are part of the type itself. However, if we consider the *inner
/// fn type*, that type has an escaping region: `'a`.
///
/// Note that what I'm calling an "escaping region" is often just called a "free region". However,
/// we already use the term "free region". It refers to the regions that we use to represent bound
/// regions on a fn definition while we are typechecking its body.
///
/// To clarify, conceptually there is no particular difference between an "escaping" region and a
/// "free" region. However, there is a big difference in practice. Basically, when "entering" a
/// binding level, one is generally required to do some sort of processing to a bound region, such
/// as replacing it with a fresh/skolemized region, or making an entry in the environment to
/// represent the scope to which it is attached, etc. An escaping region represents a bound region
/// for which this processing has not yet been done.
pub fn type_has_escaping_regions(ty: Ty) -> bool {
type_escapes_depth(ty, 0)
}
pub fn type_escapes_depth(ty: Ty, depth: u32) -> bool {
ty.region_depth > depth
}
#[deriving(Clone, PartialEq, Eq, Hash, Show)]
pub struct BareFnTy<'tcx> {
pub unsafety: ast::Unsafety,
pub abi: abi::Abi,
pub sig: PolyFnSig<'tcx>,
}
#[deriving(Clone, PartialEq, Eq, Hash, Show)]
pub struct ClosureTy<'tcx> {
pub unsafety: ast::Unsafety,
pub onceness: ast::Onceness,
pub store: TraitStore,
pub bounds: ExistentialBounds<'tcx>,
pub sig: PolyFnSig<'tcx>,
pub abi: abi::Abi,
}
#[deriving(Clone, Copy, PartialEq, Eq, Hash)]
pub enum FnOutput<'tcx> {
FnConverging(Ty<'tcx>),
FnDiverging
}
impl<'tcx> FnOutput<'tcx> {
pub fn unwrap(self) -> Ty<'tcx> {
match self {
ty::FnConverging(t) => t,
ty::FnDiverging => unreachable!()
}
}
}
/// Signature of a function type, which I have arbitrarily
/// decided to use to refer to the input/output types.
///
/// - `inputs` is the list of arguments and their modes.
/// - `output` is the return type.
/// - `variadic` indicates whether this is a varidic function. (only true for foreign fns)
#[deriving(Clone, PartialEq, Eq, Hash)]
pub struct FnSig<'tcx> {
pub inputs: Vec<Ty<'tcx>>,
pub output: FnOutput<'tcx>,
pub variadic: bool
}
pub type PolyFnSig<'tcx> = Binder<FnSig<'tcx>>;
#[deriving(Clone, Copy, PartialEq, Eq, Hash, Show)]
pub struct ParamTy {
pub space: subst::ParamSpace,
pub idx: u32,
pub name: ast::Name,
}
/// A [De Bruijn index][dbi] is a standard means of representing
/// regions (and perhaps later types) in a higher-ranked setting. In
/// particular, imagine a type like this:
///
/// for<'a> fn(for<'b> fn(&'b int, &'a int), &'a char)
/// ^ ^ | | |
/// | | | | |
/// | +------------+ 1 | |
/// | | |
/// +--------------------------------+ 2 |
/// | |
/// +------------------------------------------+ 1
///
/// In this type, there are two binders (the outer fn and the inner
/// fn). We need to be able to determine, for any given region, which
/// fn type it is bound by, the inner or the outer one. There are
/// various ways you can do this, but a De Bruijn index is one of the
/// more convenient and has some nice properties. The basic idea is to
/// count the number of binders, inside out. Some examples should help
/// clarify what I mean.
///
/// Let's start with the reference type `&'b int` that is the first
/// argument to the inner function. This region `'b` is assigned a De
/// Bruijn index of 1, meaning "the innermost binder" (in this case, a
/// fn). The region `'a` that appears in the second argument type (`&'a
/// int`) would then be assigned a De Bruijn index of 2, meaning "the
/// second-innermost binder". (These indices are written on the arrays
/// in the diagram).
///
/// What is interesting is that De Bruijn index attached to a particular
/// variable will vary depending on where it appears. For example,
/// the final type `&'a char` also refers to the region `'a` declared on
/// the outermost fn. But this time, this reference is not nested within
/// any other binders (i.e., it is not an argument to the inner fn, but
/// rather the outer one). Therefore, in this case, it is assigned a
/// De Bruijn index of 1, because the innermost binder in that location
/// is the outer fn.
///
/// [dbi]: http://en.wikipedia.org/wiki/De_Bruijn_index
#[deriving(Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, Show, Copy)]
pub struct DebruijnIndex {
// We maintain the invariant that this is never 0. So 1 indicates
// the innermost binder. To ensure this, create with `DebruijnIndex::new`.
pub depth: u32,
}
/// Representation of regions:
#[deriving(Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, Show, Copy)]
pub enum Region {
// Region bound in a type or fn declaration which will be
// substituted 'early' -- that is, at the same time when type
// parameters are substituted.
ReEarlyBound(/* param id */ ast::NodeId,
subst::ParamSpace,
/*index*/ u32,
ast::Name),
// Region bound in a function scope, which will be substituted when the
// function is called.
ReLateBound(DebruijnIndex, BoundRegion),
/// When checking a function body, the types of all arguments and so forth
/// that refer to bound region parameters are modified to refer to free
/// region parameters.
ReFree(FreeRegion),
/// A concrete region naming some expression within the current function.
ReScope(region::CodeExtent),
/// Static data that has an "infinite" lifetime. Top in the region lattice.
ReStatic,
/// A region variable. Should not exist after typeck.
ReInfer(InferRegion),
/// Empty lifetime is for data that is never accessed.
/// Bottom in the region lattice. We treat ReEmpty somewhat
/// specially; at least right now, we do not generate instances of
/// it during the GLB computations, but rather
/// generate an error instead. This is to improve error messages.
/// The only way to get an instance of ReEmpty is to have a region
/// variable with no constraints.
ReEmpty,
}
/// 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.
#[deriving(Clone, Copy, PartialEq, Eq, Hash, Show)]
pub struct UpvarId {
pub var_id: ast::NodeId,
pub closure_expr_id: ast::NodeId,
}
#[deriving(Clone, PartialEq, Eq, Hash, Show, 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 int = ...;
/// 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 int }
/// let x: &mut int = ...;
/// 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 int }
/// let x: &mut int = ...;
/// 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 borrowing of an upvar. This is computed
/// during `typeck`, specifically by `regionck`. The general idea is
/// that the compiler analyses treat closures like:
///
/// let closure: &'e fn() = || {
/// x = 1; // upvar x is assigned to
/// use(y); // upvar y is read
/// foo(&z); // upvar z is borrowed immutably
/// };
///
/// as if they were "desugared" to something loosely like:
///
/// struct Vars<'x,'y,'z> { x: &'x mut int,
/// y: &'y const int,
/// z: &'z int }
/// let closure: &'e fn() = {
/// fn f(env: &Vars) {
/// *env.x = 1;
/// use(*env.y);
/// foo(env.z);
/// }
/// let env: &'e mut Vars<'x,'y,'z> = &mut Vars { x: &'x mut x,
/// y: &'y const y,
/// z: &'z z };
/// (env, f)
/// };
///
/// This is basically what happens at runtime. The closure is basically
/// an existentially quantified version of the `(env, f)` pair.
///
/// This data structure indicates the region and mutability of a single
/// one of the `x...z` borrows.
///
/// It may not be obvious why each borrowed variable gets its own
/// lifetime (in the desugared version of the example, these are indicated
/// by the lifetime parameters `'x`, `'y`, and `'z` in the `Vars` definition).
/// Each such lifetime must encompass the lifetime `'e` of the closure itself,
/// but need not be identical to it. The reason that this makes sense:
///
/// - Callers are only permitted to invoke the closure, and hence to
/// use the pointers, within the lifetime `'e`, so clearly `'e` must
/// be a sublifetime of `'x...'z`.
/// - The closure creator knows which upvars were borrowed by the closure
/// and thus `x...z` will be reserved for `'x...'z` respectively.
/// - Through mutation, the borrowed upvars can actually escape
/// the closure, so sometimes it is necessary for them to be larger
/// than the closure lifetime itself.
#[deriving(PartialEq, Clone, RustcEncodable, RustcDecodable, Show, Copy)]
pub struct UpvarBorrow {
pub kind: BorrowKind,
pub region: ty::Region,
}
pub type UpvarBorrowMap = FnvHashMap<UpvarId, UpvarBorrow>;
impl Region {
pub fn is_bound(&self) -> bool {
match *self {
ty::ReEarlyBound(..) => true,
ty::ReLateBound(..) => true,
_ => false
}
}
pub fn escapes_depth(&self, depth: u32) -> bool {
match *self {
ty::ReLateBound(debruijn, _) => debruijn.depth > depth,
_ => false,
}
}
}
#[deriving(Clone, PartialEq, PartialOrd, Eq, Ord, Hash,
RustcEncodable, RustcDecodable, Show, Copy)]
/// A "free" region `fr` can be interpreted as "some region
/// at least as big as the scope `fr.scope`".
pub struct FreeRegion {
pub scope: region::CodeExtent,
pub bound_region: BoundRegion
}
#[deriving(Clone, PartialEq, PartialOrd, Eq, Ord, Hash,
RustcEncodable, RustcDecodable, Show, Copy)]
pub enum BoundRegion {
/// An anonymous region parameter for a given fn (&T)
BrAnon(u32),
/// Named region parameters for functions (a in &'a T)
///
/// The def-id is needed to distinguish free regions in
/// the event of shadowing.
BrNamed(ast::DefId, ast::Name),
/// Fresh bound identifiers created during GLB computations.
BrFresh(u32),
// Anonymous region for the implicit env pointer parameter
// to a closure
BrEnv
}
// NB: If you change this, you'll probably want to change the corresponding
// AST structure in libsyntax/ast.rs as well.
#[deriving(Clone, PartialEq, Eq, Hash, Show)]
pub enum sty<'tcx> {
ty_bool,
ty_char,
ty_int(ast::IntTy),
ty_uint(ast::UintTy),
ty_float(ast::FloatTy),
/// Substs here, possibly against intuition, *may* contain `ty_param`s.
/// That is, even after substitution it is possible that there are type
/// variables. This happens when the `ty_enum` corresponds to an enum
/// definition and not a concrete use of it. To get the correct `ty_enum`
/// from the tcx, use the `NodeId` from the `ast::Ty` and look it up in
/// the `ast_ty_to_ty_cache`. This is probably true for `ty_struct` as
/// well.`
ty_enum(DefId, &'tcx Substs<'tcx>),
ty_uniq(Ty<'tcx>),
ty_str,
ty_vec(Ty<'tcx>, Option<uint>), // Second field is length.
ty_ptr(mt<'tcx>),
ty_rptr(&'tcx Region, mt<'tcx>),
// If the def-id is Some(_), then this is the type of a specific
// fn item. Otherwise, if None(_), it a fn pointer type.
ty_bare_fn(Option<DefId>, &'tcx BareFnTy<'tcx>),
ty_closure(Box<ClosureTy<'tcx>>),
ty_trait(Box<TyTrait<'tcx>>),
ty_struct(DefId, &'tcx Substs<'tcx>),
ty_unboxed_closure(DefId, &'tcx Region, &'tcx Substs<'tcx>),
ty_tup(Vec<Ty<'tcx>>),
ty_projection(ProjectionTy<'tcx>),
ty_param(ParamTy), // type parameter
ty_open(Ty<'tcx>), // A deref'ed fat pointer, i.e., a dynamically sized value
// and its size. Only ever used in trans. It is not necessary
// earlier since we don't need to distinguish a DST with its
// size (e.g., in a deref) vs a DST with the size elsewhere (
// e.g., in a field).
ty_infer(InferTy), // something used only during inference/typeck
ty_err, // Also only used during inference/typeck, to represent
// the type of an erroneous expression (helps cut down
// on non-useful type error messages)
}
#[deriving(Clone, PartialEq, Eq, Hash, Show)]
pub struct TyTrait<'tcx> {
pub principal: ty::PolyTraitRef<'tcx>,
pub bounds: ExistentialBounds<'tcx>,
}
impl<'tcx> TyTrait<'tcx> {
pub fn principal_def_id(&self) -> ast::DefId {
self.principal.0.def_id
}
/// Object types don't have a self-type specified. Therefore, when
/// we convert the principal trait-ref into a normal trait-ref,
/// you must give *some* self-type. A common choice is `mk_err()`
/// or some skolemized type.
pub fn principal_trait_ref_with_self_ty(&self,
tcx: &ctxt<'tcx>,
self_ty: Ty<'tcx>)
-> ty::PolyTraitRef<'tcx>
{
// otherwise the escaping regions would be captured by the binder
assert!(!self_ty.has_escaping_regions());
ty::Binder(Rc::new(ty::TraitRef {
def_id: self.principal.0.def_id,
substs: tcx.mk_substs(self.principal.0.substs.with_self_ty(self_ty)),
}))
}
pub fn projection_bounds_with_self_ty(&self,
tcx: &ctxt<'tcx>,
self_ty: Ty<'tcx>)
-> Vec<ty::PolyProjectionPredicate<'tcx>>
{
// otherwise the escaping regions would be captured by the binders
assert!(!self_ty.has_escaping_regions());
self.bounds.projection_bounds.iter()
.map(|in_poly_projection_predicate| {
let in_projection_ty = &in_poly_projection_predicate.0.projection_ty;
let substs = tcx.mk_substs(in_projection_ty.trait_ref.substs.with_self_ty(self_ty));
let trait_ref =
Rc::new(ty::TraitRef::new(in_projection_ty.trait_ref.def_id,
substs));
let projection_ty = ty::ProjectionTy {
trait_ref: trait_ref,
item_name: in_projection_ty.item_name
};
ty::Binder(ty::ProjectionPredicate {
projection_ty: projection_ty,
ty: in_poly_projection_predicate.0.ty
})
})
.collect()
}
}
/// A complete reference to a trait. These take numerous guises in syntax,
/// but perhaps the most recognizable form is in a where clause:
///
/// T : Foo<U>
///
/// This would be represented by a trait-reference where the def-id is the
/// def-id for the trait `Foo` and the substs defines `T` as parameter 0 in the
/// `SelfSpace` and `U` as parameter 0 in the `TypeSpace`.
///
/// Trait references also appear in object types like `Foo<U>`, but in
/// that case the `Self` parameter is absent from the substitutions.
///
/// Note that a `TraitRef` introduces a level of region binding, to
/// account for higher-ranked trait bounds like `T : for<'a> Foo<&'a
/// U>` or higher-ranked object types.
#[deriving(Clone, PartialEq, Eq, Hash, Show)]
pub struct TraitRef<'tcx> {
pub def_id: DefId,
pub substs: &'tcx Substs<'tcx>,
}
pub type PolyTraitRef<'tcx> = Binder<Rc<TraitRef<'tcx>>>;
impl<'tcx> PolyTraitRef<'tcx> {
pub fn self_ty(&self) -> Ty<'tcx> {
self.0.self_ty()
}
pub fn def_id(&self) -> ast::DefId {
self.0.def_id
}
pub fn substs(&self) -> &'tcx Substs<'tcx> {
self.0.substs
}
pub fn input_types(&self) -> &[Ty<'tcx>] {
self.0.input_types()
}
pub fn to_poly_trait_predicate(&self) -> PolyTraitPredicate<'tcx> {
// Note that we preserve binding levels
Binder(TraitPredicate { trait_ref: self.0.clone() })
}
}
/// Binder is a binder for higher-ranked lifetimes. It is part of the
/// compiler's representation for things like `for<'a> Fn(&'a int)`
/// (which would be represented by the type `PolyTraitRef ==
/// Binder<TraitRef>`). Note that when we skolemize, instantiate,
/// erase, or otherwise "discharge" these bound reons, we change the
/// type from `Binder<T>` to just `T` (see
/// e.g. `liberate_late_bound_regions`).
#[deriving(Clone, PartialEq, Eq, Hash, Show)]
pub struct Binder<T>(pub T);
#[deriving(Clone, Copy, PartialEq)]
pub enum IntVarValue {
IntType(ast::IntTy),
UintType(ast::UintTy),
}
#[deriving(Clone, Copy, Show)]
pub enum terr_vstore_kind {
terr_vec,
terr_str,
terr_fn,
terr_trait
}
#[deriving(Clone, Copy, Show)]
pub struct expected_found<T> {
pub expected: T,
pub found: T
}
// Data structures used in type unification
#[deriving(Clone, Copy, Show)]
pub enum type_err<'tcx> {
terr_mismatch,
terr_unsafety_mismatch(expected_found<ast::Unsafety>),
terr_onceness_mismatch(expected_found<Onceness>),
terr_abi_mismatch(expected_found<abi::Abi>),
terr_mutability,
terr_sigil_mismatch(expected_found<TraitStore>),
terr_box_mutability,
terr_ptr_mutability,
terr_ref_mutability,
terr_vec_mutability,
terr_tuple_size(expected_found<uint>),
terr_fixed_array_size(expected_found<uint>),
terr_ty_param_size(expected_found<uint>),
terr_arg_count,
terr_regions_does_not_outlive(Region, Region),
terr_regions_not_same(Region, Region),
terr_regions_no_overlap(Region, Region),
terr_regions_insufficiently_polymorphic(BoundRegion, Region),
terr_regions_overly_polymorphic(BoundRegion, Region),
terr_trait_stores_differ(terr_vstore_kind, expected_found<TraitStore>),
terr_sorts(expected_found<Ty<'tcx>>),
terr_integer_as_char,
terr_int_mismatch(expected_found<IntVarValue>),
terr_float_mismatch(expected_found<ast::FloatTy>),
terr_traits(expected_found<ast::DefId>),
terr_builtin_bounds(expected_found<BuiltinBounds>),
terr_variadic_mismatch(expected_found<bool>),
terr_cyclic_ty,
terr_convergence_mismatch(expected_found<bool>),
terr_projection_name_mismatched(expected_found<ast::Name>),
terr_projection_bounds_length(expected_found<uint>),
}
/// Bounds suitable for a named type parameter like `A` in `fn foo<A>`
/// as well as the existential type parameter in an object type.
#[deriving(PartialEq, Eq, Hash, Clone, Show)]
pub struct ParamBounds<'tcx> {
pub region_bounds: Vec<ty::Region>,
pub builtin_bounds: BuiltinBounds,
pub trait_bounds: Vec<PolyTraitRef<'tcx>>,
pub projection_bounds: Vec<PolyProjectionPredicate<'tcx>>,
}
/// Bounds suitable for an existentially quantified type parameter
/// such as those that appear in object types or closure types. The
/// major difference between this case and `ParamBounds` is that
/// general purpose trait bounds are omitted and there must be
/// *exactly one* region.
#[deriving(PartialEq, Eq, Hash, Clone, Show)]
pub struct ExistentialBounds<'tcx> {
pub region_bound: ty::Region,
pub builtin_bounds: BuiltinBounds,
pub projection_bounds: Vec<PolyProjectionPredicate<'tcx>>,
}
pub type BuiltinBounds = EnumSet<BuiltinBound>;
#[deriving(Clone, RustcEncodable, PartialEq, Eq, RustcDecodable, Hash,
Show, Copy)]
#[repr(uint)]
pub enum BuiltinBound {
BoundSend,
BoundSized,
BoundCopy,
BoundSync,
}
pub fn empty_builtin_bounds() -> BuiltinBounds {
EnumSet::new()
}
pub fn all_builtin_bounds() -> BuiltinBounds {
let mut set = EnumSet::new();
set.insert(BoundSend);
set.insert(BoundSized);
set.insert(BoundSync);
set
}
/// An existential bound that does not implement any traits.
pub fn region_existential_bound<'tcx>(r: ty::Region) -> ExistentialBounds<'tcx> {
ty::ExistentialBounds { region_bound: r,
builtin_bounds: empty_builtin_bounds(),
projection_bounds: Vec::new() }
}
impl CLike for BuiltinBound {
fn to_uint(&self) -> uint {
*self as uint
}
fn from_uint(v: uint) -> BuiltinBound {
unsafe { mem::transmute(v) }
}
}
#[deriving(Clone, Copy, PartialEq, Eq, Hash)]
pub struct TyVid {
pub index: u32
}
#[deriving(Clone, Copy, PartialEq, Eq, Hash)]
pub struct IntVid {
pub index: u32
}
#[deriving(Clone, Copy, PartialEq, Eq, Hash)]
pub struct FloatVid {
pub index: u32
}
#[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Copy)]
pub struct RegionVid {
pub index: u32
}
#[deriving(Clone, Copy, PartialEq, Eq, Hash)]
pub enum InferTy {
TyVar(TyVid),
IntVar(IntVid),
FloatVar(FloatVid),
/// A `FreshTy` is one that is generated as a replacement for an
/// unbound type variable. This is convenient for caching etc. See
/// `middle::infer::freshen` for more details.
FreshTy(u32),
// FIXME -- once integral fallback is impl'd, we should remove
// this type. It's only needed to prevent spurious errors for
// integers whose type winds up never being constrained.
FreshIntTy(u32),
}
#[deriving(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Hash, Show, Copy)]
pub enum UnconstrainedNumeric {
UnconstrainedFloat,
UnconstrainedInt,
Neither,
}
#[deriving(Clone, RustcEncodable, RustcDecodable, Eq, Hash, Show, Copy)]
pub enum InferRegion {
ReVar(RegionVid),
ReSkolemized(u32, BoundRegion)
}
impl cmp::PartialEq for InferRegion {
fn eq(&self, other: &InferRegion) -> bool {
match ((*self), *other) {
(ReVar(rva), ReVar(rvb)) => {
rva == rvb
}
(ReSkolemized(rva, _), ReSkolemized(rvb, _)) => {
rva == rvb
}
_ => false
}
}
fn ne(&self, other: &InferRegion) -> bool {
!((*self) == (*other))
}
}
impl fmt::Show for TyVid {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result{
write!(f, "_#{}t", self.index)
}
}
impl fmt::Show for IntVid {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "_#{}i", self.index)
}
}
impl fmt::Show for FloatVid {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "_#{}f", self.index)
}
}
impl fmt::Show for RegionVid {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "'_#{}r", self.index)
}
}
impl<'tcx> fmt::Show for FnSig<'tcx> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
// grr, without tcx not much we can do.
write!(f, "(...)")
}
}
impl fmt::Show for InferTy {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match *self {
TyVar(ref v) => v.fmt(f),
IntVar(ref v) => v.fmt(f),
FloatVar(ref v) => v.fmt(f),
FreshTy(v) => write!(f, "FreshTy({})", v),
FreshIntTy(v) => write!(f, "FreshIntTy({})", v),
}
}
}
impl fmt::Show for IntVarValue {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match *self {
IntType(ref v) => v.fmt(f),
UintType(ref v) => v.fmt(f),
}
}
}
#[deriving(Clone, Show)]
pub struct TypeParameterDef<'tcx> {
pub name: ast::Name,
pub def_id: ast::DefId,
pub space: subst::ParamSpace,
pub index: u32,
pub bounds: ParamBounds<'tcx>,
pub default: Option<Ty<'tcx>>,
}
#[deriving(RustcEncodable, RustcDecodable, Clone, Show)]
pub struct RegionParameterDef {
pub name: ast::Name,
pub def_id: ast::DefId,
pub space: subst::ParamSpace,
pub index: u32,
pub bounds: Vec<ty::Region>,
}
impl RegionParameterDef {
pub fn to_early_bound_region(&self) -> ty::Region {
ty::ReEarlyBound(self.def_id.node, self.space, self.index, self.name)
}
}
/// Information about the formal type/lifetime parameters associated
/// with an item or method. Analogous to ast::Generics.
#[deriving(Clone, Show)]
pub struct Generics<'tcx> {
pub types: VecPerParamSpace<TypeParameterDef<'tcx>>,
pub regions: VecPerParamSpace<RegionParameterDef>,
pub predicates: VecPerParamSpace<Predicate<'tcx>>,
}
impl<'tcx> Generics<'tcx> {
pub fn empty() -> Generics<'tcx> {
Generics {
types: VecPerParamSpace::empty(),
regions: VecPerParamSpace::empty(),
predicates: VecPerParamSpace::empty(),
}
}
pub fn has_type_params(&self, space: subst::ParamSpace) -> bool {
!self.types.is_empty_in(space)
}
pub fn has_region_params(&self, space: subst::ParamSpace) -> bool {
!self.regions.is_empty_in(space)
}
pub fn to_bounds(&self, tcx: &ty::ctxt<'tcx>, substs: &Substs<'tcx>)
-> GenericBounds<'tcx> {
GenericBounds {
predicates: self.predicates.subst(tcx, substs),
}
}
}
#[deriving(Clone, PartialEq, Eq, Hash, Show)]
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 parameters in the `TypeSpace`.
Trait(PolyTraitPredicate<'tcx>),
/// where `T1 == T2`.
Equate(PolyEquatePredicate<'tcx>),
/// where 'a : 'b
RegionOutlives(PolyRegionOutlivesPredicate),
/// where T : 'a
TypeOutlives(PolyTypeOutlivesPredicate<'tcx>),
/// where <T as TraitRef>::Name == X, approximately.
/// See `ProjectionPredicate` struct for details.
Projection(PolyProjectionPredicate<'tcx>),
}
#[deriving(Clone, PartialEq, Eq, Hash, Show)]
pub struct TraitPredicate<'tcx> {
pub trait_ref: Rc<TraitRef<'tcx>>
}
pub type PolyTraitPredicate<'tcx> = ty::Binder<TraitPredicate<'tcx>>;
impl<'tcx> TraitPredicate<'tcx> {
pub fn def_id(&self) -> ast::DefId {
self.trait_ref.def_id
}
pub fn input_types(&self) -> &[Ty<'tcx>] {
self.trait_ref.substs.types.as_slice()
}
pub fn self_ty(&self) -> Ty<'tcx> {
self.trait_ref.self_ty()
}
}
impl<'tcx> PolyTraitPredicate<'tcx> {
pub fn def_id(&self) -> ast::DefId {
self.0.def_id()
}
}
#[deriving(Clone, PartialEq, Eq, Hash, Show)]
pub struct EquatePredicate<'tcx>(pub Ty<'tcx>, pub Ty<'tcx>); // `0 == 1`
pub type PolyEquatePredicate<'tcx> = ty::Binder<EquatePredicate<'tcx>>;
#[deriving(Clone, PartialEq, Eq, Hash, Show)]
pub struct OutlivesPredicate<A,B>(pub A, pub B); // `A : B`
pub type PolyOutlivesPredicate<A,B> = ty::Binder<OutlivesPredicate<A,B>>;
pub type PolyRegionOutlivesPredicate = PolyOutlivesPredicate<ty::Region, ty::Region>;
pub type PolyTypeOutlivesPredicate<'tcx> = PolyOutlivesPredicate<Ty<'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.
#[deriving(Clone, PartialEq, Eq, Hash, Show)]
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 sort_key(&self) -> (ast::DefId, ast::Name) {
self.0.projection_ty.sort_key()
}
}
/// Represents the projection of an associated type. In explicit UFCS
/// form this would be written `<T as Trait<..>>::N`.
#[deriving(Clone, PartialEq, Eq, Hash, Show)]
pub struct ProjectionTy<'tcx> {
/// The trait reference `T as Trait<..>`.
pub trait_ref: Rc<ty::TraitRef<'tcx>>,
/// The name `N` of the associated type.
pub item_name: ast::Name,
}
impl<'tcx> ProjectionTy<'tcx> {
pub fn sort_key(&self) -> (ast::DefId, ast::Name) {
(self.trait_ref.def_id, self.item_name)
}
}
pub trait ToPolyTraitRef<'tcx> {
fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx>;
}
impl<'tcx> ToPolyTraitRef<'tcx> for Rc<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> {
// We are just preserving the binder levels here
ty::Binder(self.0.trait_ref.clone())
}
}
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.clone())
}
}
pub trait AsPredicate<'tcx> {
fn as_predicate(&self) -> Predicate<'tcx>;
}
impl<'tcx> AsPredicate<'tcx> for Rc<TraitRef<'tcx>> {
fn as_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> AsPredicate<'tcx> for PolyTraitRef<'tcx> {
fn as_predicate(&self) -> Predicate<'tcx> {
ty::Predicate::Trait(self.to_poly_trait_predicate())
}
}
impl<'tcx> AsPredicate<'tcx> for PolyEquatePredicate<'tcx> {
fn as_predicate(&self) -> Predicate<'tcx> {
Predicate::Equate(self.clone())
}
}
impl<'tcx> AsPredicate<'tcx> for PolyRegionOutlivesPredicate {
fn as_predicate(&self) -> Predicate<'tcx> {
Predicate::RegionOutlives(self.clone())
}
}
impl<'tcx> AsPredicate<'tcx> for PolyTypeOutlivesPredicate<'tcx> {
fn as_predicate(&self) -> Predicate<'tcx> {
Predicate::TypeOutlives(self.clone())
}
}
impl<'tcx> AsPredicate<'tcx> for PolyProjectionPredicate<'tcx> {
fn as_predicate(&self) -> Predicate<'tcx> {
Predicate::Projection(self.clone())
}
}
impl<'tcx> Predicate<'tcx> {
pub fn has_escaping_regions(&self) -> bool {
match *self {
Predicate::Trait(ref trait_ref) => trait_ref.has_escaping_regions(),
Predicate::Equate(ref p) => p.has_escaping_regions(),
Predicate::RegionOutlives(ref p) => p.has_escaping_regions(),
Predicate::TypeOutlives(ref p) => p.has_escaping_regions(),
Predicate::Projection(ref p) => p.has_escaping_regions(),
}
}
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::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 `GenericBounds` list from a
/// `Generics` by using the `to_bounds` method. Note that this method
/// reflects an important semantic invariant of `GenericBounds`: while
/// the bounds in a `Generics` are expressed in terms of the bound type
/// parameters of the impl/trait/whatever, a `GenericBounds` 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 `Generics` for `Foo` would contain a list of bounds like
/// `[[], [U:Bar<T>]]`. Now if there were some particular reference
/// like `Foo<int,uint>`, then the `GenericBounds` would be `[[],
/// [uint:Bar<int>]]`.
#[deriving(Clone, Show)]
pub struct GenericBounds<'tcx> {
pub predicates: VecPerParamSpace<Predicate<'tcx>>,
}
impl<'tcx> GenericBounds<'tcx> {
pub fn empty() -> GenericBounds<'tcx> {
GenericBounds { predicates: VecPerParamSpace::empty() }
}
pub fn has_escaping_regions(&self) -> bool {
self.predicates.any(|p| p.has_escaping_regions())
}
pub fn is_empty(&self) -> bool {
self.predicates.is_empty()
}
}
impl<'tcx> TraitRef<'tcx> {
pub fn new(def_id: ast::DefId, substs: &'tcx Substs<'tcx>) -> TraitRef<'tcx> {
TraitRef { def_id: def_id, substs: substs }
}
pub fn self_ty(&self) -> Ty<'tcx> {
self.substs.self_ty().unwrap()
}
pub fn input_types(&self) -> &[Ty<'tcx>] {
// 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.as_slice()
}
}
/// 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.
#[deriving(Clone)]
pub struct ParameterEnvironment<'tcx> {
/// 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 free_substs: 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: ty::Region,
/// Obligations that the caller must satisfy. This is basically
/// the set of bounds on the in-scope type parameters, translated
/// into Obligations.
pub caller_bounds: ty::GenericBounds<'tcx>,
/// Caches the results of trait selection. This cache is used
/// for things that have to do with the parameters in scope.
pub selection_cache: traits::SelectionCache<'tcx>,
}
impl<'tcx> ParameterEnvironment<'tcx> {
pub fn for_item(cx: &ctxt<'tcx>, id: NodeId) -> ParameterEnvironment<'tcx> {
match cx.map.find(id) {
Some(ast_map::NodeImplItem(ref impl_item)) => {
match **impl_item {
ast::MethodImplItem(ref method) => {
let method_def_id = ast_util::local_def(id);
match ty::impl_or_trait_item(cx, method_def_id) {
MethodTraitItem(ref method_ty) => {
let method_generics = &method_ty.generics;
construct_parameter_environment(
cx,
method_generics,
method.pe_body().id)
}
TypeTraitItem(_) => {
cx.sess
.bug("ParameterEnvironment::for_item(): \
can't create a parameter environment \
for type trait items")
}
}
}
ast::TypeImplItem(_) => {
cx.sess.bug("ParameterEnvironment::for_item(): \
can't create a parameter environment \
for type impl items")
}
}
}
Some(ast_map::NodeTraitItem(trait_method)) => {
match *trait_method {
ast::RequiredMethod(ref required) => {
cx.sess.span_bug(required.span,
"ParameterEnvironment::for_item():
can't create a parameter \
environment for required trait \
methods")
}
ast::ProvidedMethod(ref method) => {
let method_def_id = ast_util::local_def(id);
match ty::impl_or_trait_item(cx, method_def_id) {
MethodTraitItem(ref method_ty) => {
let method_generics = &method_ty.generics;
construct_parameter_environment(
cx,
method_generics,
method.pe_body().id)
}
TypeTraitItem(_) => {
cx.sess
.bug("ParameterEnvironment::for_item(): \
can't create a parameter environment \
for type trait items")
}
}
}
ast::TypeTraitItem(_) => {
cx.sess.bug("ParameterEnvironment::from_item(): \
can't create a parameter environment \
for type trait items")
}
}
}
Some(ast_map::NodeItem(item)) => {
match item.node {
ast::ItemFn(_, _, _, _, ref body) => {
// We assume this is a function.
let fn_def_id = ast_util::local_def(id);
let fn_pty = ty::lookup_item_type(cx, fn_def_id);
construct_parameter_environment(cx,
&fn_pty.generics,
body.id)
}
ast::ItemEnum(..) |
ast::ItemStruct(..) |
ast::ItemImpl(..) |
ast::ItemConst(..) |
ast::ItemStatic(..) => {
let def_id = ast_util::local_def(id);
let pty = ty::lookup_item_type(cx, def_id);
construct_parameter_environment(cx, &pty.generics, id)
}
_ => {
cx.sess.span_bug(item.span,
"ParameterEnvironment::from_item():
can't create a parameter \
environment for this kind of item")
}
}
}
Some(ast_map::NodeExpr(..)) => {
// This is a convenience to allow closures to work.
ParameterEnvironment::for_item(cx, cx.map.get_parent(id))
}
_ => {
cx.sess.bug(format!("ParameterEnvironment::from_item(): \
`{}` is not an item",
cx.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`.
#[deriving(Clone, Show)]
pub struct TypeScheme<'tcx> {
pub generics: Generics<'tcx>,
pub ty: Ty<'tcx>
}
/// As `TypeScheme` but for a trait ref.
pub struct TraitDef<'tcx> {
pub unsafety: ast::Unsafety,
/// Generic type definitions. Note that `Self` is listed in here
/// as having a single bound, the trait itself (e.g., in the trait
/// `Eq`, there is a single bound `Self : Eq`). This is so that
/// default methods get to assume that the `Self` parameters
/// implements the trait.
pub generics: Generics<'tcx>,
/// The "supertrait" bounds.
pub bounds: ParamBounds<'tcx>,
pub trait_ref: Rc<ty::TraitRef<'tcx>>,
/// A list of the associated types defined in this trait. Useful
/// for resolving `X::Foo` type markers.
pub associated_type_names: Vec<ast::Name>,
}
/// Records the substitutions used to translate the polytype for an
/// item into the monotype of an item reference.
#[deriving(Clone)]
pub struct ItemSubsts<'tcx> {
pub substs: Substs<'tcx>,
}
/// Records information about each unboxed closure.
#[deriving(Clone)]
pub struct UnboxedClosure<'tcx> {
/// The type of the unboxed closure.
pub closure_type: ClosureTy<'tcx>,
/// The kind of unboxed closure this is.
pub kind: UnboxedClosureKind,
}
#[deriving(Clone, Copy, PartialEq, Eq, Show)]
pub enum UnboxedClosureKind {
FnUnboxedClosureKind,
FnMutUnboxedClosureKind,
FnOnceUnboxedClosureKind,
}
impl UnboxedClosureKind {
pub fn trait_did(&self, cx: &ctxt) -> ast::DefId {
let result = match *self {
FnUnboxedClosureKind => cx.lang_items.require(FnTraitLangItem),
FnMutUnboxedClosureKind => {
cx.lang_items.require(FnMutTraitLangItem)
}
FnOnceUnboxedClosureKind => {
cx.lang_items.require(FnOnceTraitLangItem)
}
};
match result {
Ok(trait_did) => trait_did,
Err(err) => cx.sess.fatal(err[]),
}
}
}
pub trait UnboxedClosureTyper<'tcx> {
fn unboxed_closure_kind(&self,
def_id: ast::DefId)
-> ty::UnboxedClosureKind;
fn unboxed_closure_type(&self,
def_id: ast::DefId,
substs: &subst::Substs<'tcx>)
-> ty::ClosureTy<'tcx>;
// Returns `None` if the upvar types cannot yet be definitively determined.
fn unboxed_closure_upvars(&self,
def_id: ast::DefId,
substs: &Substs<'tcx>)
-> Option<Vec<UnboxedClosureUpvar<'tcx>>>;
}
impl<'tcx> CommonTypes<'tcx> {
fn new(arena: &'tcx TypedArena<TyS<'tcx>>,
interner: &mut FnvHashMap<InternedTy<'tcx>, Ty<'tcx>>)
-> CommonTypes<'tcx>
{
CommonTypes {
bool: intern_ty(arena, interner, ty_bool),
char: intern_ty(arena, interner, ty_char),
err: intern_ty(arena, interner, ty_err),
int: intern_ty(arena, interner, ty_int(ast::TyI)),
i8: intern_ty(arena, interner, ty_int(ast::TyI8)),
i16: intern_ty(arena, interner, ty_int(ast::TyI16)),
i32: intern_ty(arena, interner, ty_int(ast::TyI32)),
i64: intern_ty(arena, interner, ty_int(ast::TyI64)),
uint: intern_ty(arena, interner, ty_uint(ast::TyU)),
u8: intern_ty(arena, interner, ty_uint(ast::TyU8)),
u16: intern_ty(arena, interner, ty_uint(ast::TyU16)),
u32: intern_ty(arena, interner, ty_uint(ast::TyU32)),
u64: intern_ty(arena, interner, ty_uint(ast::TyU64)),
f32: intern_ty(arena, interner, ty_float(ast::TyF32)),
f64: intern_ty(arena, interner, ty_float(ast::TyF64)),
}
}
}
pub fn mk_ctxt<'tcx>(s: Session,
arenas: &'tcx CtxtArenas<'tcx>,
dm: DefMap,
named_region_map: resolve_lifetime::NamedRegionMap,
map: ast_map::Map<'tcx>,
freevars: RefCell<FreevarMap>,
capture_modes: RefCell<CaptureModeMap>,
region_maps: middle::region::RegionMaps,
lang_items: middle::lang_items::LanguageItems,
stability: stability::Index) -> ctxt<'tcx>
{
let mut interner = FnvHashMap::new();
let common_types = CommonTypes::new(&arenas.type_, &mut interner);
ctxt {
arenas: arenas,
interner: RefCell::new(interner),
substs_interner: RefCell::new(FnvHashMap::new()),
bare_fn_interner: RefCell::new(FnvHashMap::new()),
region_interner: RefCell::new(FnvHashMap::new()),
types: common_types,
named_region_map: named_region_map,
item_variance_map: RefCell::new(DefIdMap::new()),
variance_computed: Cell::new(false),
sess: s,
def_map: dm,
region_maps: region_maps,
node_types: RefCell::new(FnvHashMap::new()),
item_substs: RefCell::new(NodeMap::new()),
trait_refs: RefCell::new(NodeMap::new()),
trait_defs: RefCell::new(DefIdMap::new()),
object_cast_map: RefCell::new(NodeMap::new()),
map: map,
intrinsic_defs: RefCell::new(DefIdMap::new()),
freevars: freevars,
tcache: RefCell::new(DefIdMap::new()),
rcache: RefCell::new(FnvHashMap::new()),
short_names_cache: RefCell::new(FnvHashMap::new()),
tc_cache: RefCell::new(FnvHashMap::new()),
ast_ty_to_ty_cache: RefCell::new(NodeMap::new()),
enum_var_cache: RefCell::new(DefIdMap::new()),
impl_or_trait_items: RefCell::new(DefIdMap::new()),
trait_item_def_ids: RefCell::new(DefIdMap::new()),
trait_items_cache: RefCell::new(DefIdMap::new()),
impl_trait_cache: RefCell::new(DefIdMap::new()),
ty_param_defs: RefCell::new(NodeMap::new()),
adjustments: RefCell::new(NodeMap::new()),
normalized_cache: RefCell::new(FnvHashMap::new()),
lang_items: lang_items,
provided_method_sources: RefCell::new(DefIdMap::new()),
struct_fields: RefCell::new(DefIdMap::new()),
destructor_for_type: RefCell::new(DefIdMap::new()),
destructors: RefCell::new(DefIdSet::new()),
trait_impls: RefCell::new(DefIdMap::new()),
inherent_impls: RefCell::new(DefIdMap::new()),
impl_items: RefCell::new(DefIdMap::new()),
used_unsafe: RefCell::new(NodeSet::new()),
used_mut_nodes: RefCell::new(NodeSet::new()),
populated_external_types: RefCell::new(DefIdSet::new()),
populated_external_traits: RefCell::new(DefIdSet::new()),
upvar_borrow_map: RefCell::new(FnvHashMap::new()),
extern_const_statics: RefCell::new(DefIdMap::new()),
extern_const_variants: RefCell::new(DefIdMap::new()),
method_map: RefCell::new(FnvHashMap::new()),
dependency_formats: RefCell::new(FnvHashMap::new()),
unboxed_closures: RefCell::new(DefIdMap::new()),
node_lint_levels: RefCell::new(FnvHashMap::new()),
transmute_restrictions: RefCell::new(Vec::new()),
stability: RefCell::new(stability),
capture_modes: capture_modes,
associated_types: RefCell::new(DefIdMap::new()),
selection_cache: traits::SelectionCache::new(),
repr_hint_cache: RefCell::new(DefIdMap::new()),
type_impls_copy_cache: RefCell::new(HashMap::new()),
type_impls_sized_cache: RefCell::new(HashMap::new()),
}
}
// Type constructors
impl<'tcx> ctxt<'tcx> {
pub fn mk_substs(&self, substs: Substs<'tcx>) -> &'tcx Substs<'tcx> {
if let Some(substs) = self.substs_interner.borrow().get(&substs) {
return *substs;
}
let substs = self.arenas.substs.alloc(substs);
self.substs_interner.borrow_mut().insert(substs, substs);
substs
}
pub fn mk_bare_fn(&self, bare_fn: BareFnTy<'tcx>) -> &'tcx BareFnTy<'tcx> {
if let Some(bare_fn) = self.bare_fn_interner.borrow().get(&bare_fn) {
return *bare_fn;
}
let bare_fn = self.arenas.bare_fn.alloc(bare_fn);
self.bare_fn_interner.borrow_mut().insert(bare_fn, bare_fn);
bare_fn
}
pub fn mk_region(&self, region: Region) -> &'tcx Region {
if let Some(region) = self.region_interner.borrow().get(&region) {
return *region;
}
let region = self.arenas.region.alloc(region);
self.region_interner.borrow_mut().insert(region, region);
region
}
}
// Interns a type/name combination, stores the resulting box in cx.interner,
// and returns the box as cast to an unsafe ptr (see comments for Ty above).
pub fn mk_t<'tcx>(cx: &ctxt<'tcx>, st: sty<'tcx>) -> Ty<'tcx> {
let mut interner = cx.interner.borrow_mut();
intern_ty(&cx.arenas.type_, &mut *interner, st)
}
fn intern_ty<'tcx>(type_arena: &'tcx TypedArena<TyS<'tcx>>,
interner: &mut FnvHashMap<InternedTy<'tcx>, Ty<'tcx>>,
st: sty<'tcx>)
-> Ty<'tcx>
{
match interner.get(&st) {
Some(ty) => return *ty,
_ => ()
}
let flags = FlagComputation::for_sty(&st);
let ty = type_arena.alloc(TyS {
sty: st,
flags: flags.flags,
region_depth: flags.depth,
});
debug!("Interned type: {} Pointer: {}",
ty, ty as *const _);
interner.insert(InternedTy { ty: ty }, ty);
ty
}
struct FlagComputation {
flags: TypeFlags,
// maximum depth of any bound region that we have seen thus far
depth: u32,
}
impl FlagComputation {
fn new() -> FlagComputation {
FlagComputation { flags: NO_TYPE_FLAGS, depth: 0 }
}
fn for_sty(st: &sty) -> FlagComputation {
let mut result = FlagComputation::new();
result.add_sty(st);
result
}
fn add_flags(&mut self, flags: TypeFlags) {
self.flags = self.flags | flags;
}
fn add_depth(&mut self, depth: u32) {
if depth > self.depth {
self.depth = depth;
}
}
/// Adds the flags/depth from a set of types that appear within the current type, but within a
/// region binder.
fn add_bound_computation(&mut self, computation: &FlagComputation) {
self.add_flags(computation.flags);
// The types that contributed to `computation` occured within
// a region binder, so subtract one from the region depth
// within when adding the depth to `self`.
let depth = computation.depth;
if depth > 0 {
self.add_depth(depth - 1);
}
}
fn add_sty(&mut self, st: &sty) {
match st {
&ty_bool |
&ty_char |
&ty_int(_) |
&ty_float(_) |
&ty_uint(_) |
&ty_str => {
}
// You might think that we could just return ty_err for
// any type containing ty_err as a component, and get
// rid of the HAS_TY_ERR flag -- likewise for ty_bot (with
// the exception of function types that return bot).
// But doing so caused sporadic memory corruption, and
// neither I (tjc) nor nmatsakis could figure out why,
// so we're doing it this way.
&ty_err => {
self.add_flags(HAS_TY_ERR)
}
&ty_param(ref p) => {
if p.space == subst::SelfSpace {
self.add_flags(HAS_SELF);
} else {
self.add_flags(HAS_PARAMS);
}
}
&ty_unboxed_closure(_, region, substs) => {
self.add_region(*region);
self.add_substs(substs);
}
&ty_infer(_) => {
self.add_flags(HAS_TY_INFER)
}
&ty_enum(_, substs) | &ty_struct(_, substs) => {
self.add_substs(substs);
}
&ty_projection(ref data) => {
self.add_flags(HAS_PROJECTION);
self.add_substs(data.trait_ref.substs);
}
&ty_trait(box TyTrait { ref principal, ref bounds }) => {
let mut computation = FlagComputation::new();
computation.add_substs(principal.0.substs);
self.add_bound_computation(&computation);
self.add_bounds(bounds);
}
&ty_uniq(tt) | &ty_vec(tt, _) | &ty_open(tt) => {
self.add_ty(tt)
}
&ty_ptr(ref m) => {
self.add_ty(m.ty);
}
&ty_rptr(r, ref m) => {
self.add_region(*r);
self.add_ty(m.ty);
}
&ty_tup(ref ts) => {
self.add_tys(ts[]);
}
&ty_bare_fn(_, ref f) => {
self.add_fn_sig(&f.sig);
}
&ty_closure(ref f) => {
if let RegionTraitStore(r, _) = f.store {
self.add_region(r);
}
self.add_fn_sig(&f.sig);
self.add_bounds(&f.bounds);
}
}
}
fn add_ty(&mut self, ty: Ty) {
self.add_flags(ty.flags);
self.add_depth(ty.region_depth);
}
fn add_tys(&mut self, tys: &[Ty]) {
for &ty in tys.iter() {
self.add_ty(ty);
}
}
fn add_fn_sig(&mut self, fn_sig: &PolyFnSig) {
let mut computation = FlagComputation::new();
computation.add_tys(fn_sig.0.inputs[]);
if let ty::FnConverging(output) = fn_sig.0.output {
computation.add_ty(output);
}
self.add_bound_computation(&computation);
}
fn add_region(&mut self, r: Region) {
self.add_flags(HAS_REGIONS);
match r {
ty::ReInfer(_) => { self.add_flags(HAS_RE_INFER); }
ty::ReLateBound(debruijn, _) => {
self.add_flags(HAS_RE_LATE_BOUND);
self.add_depth(debruijn.depth);
}
_ => { }
}
}
fn add_substs(&mut self, substs: &Substs) {
self.add_tys(substs.types.as_slice());
match substs.regions {
subst::ErasedRegions => {}
subst::NonerasedRegions(ref regions) => {
for &r in regions.iter() {
self.add_region(r);
}
}
}
}
fn add_bounds(&mut self, bounds: &ExistentialBounds) {
self.add_region(bounds.region_bound);
}
}
pub fn mk_mach_int<'tcx>(tcx: &ctxt<'tcx>, tm: ast::IntTy) -> Ty<'tcx> {
match tm {
ast::TyI => tcx.types.int,
ast::TyI8 => tcx.types.i8,
ast::TyI16 => tcx.types.i16,
ast::TyI32 => tcx.types.i32,
ast::TyI64 => tcx.types.i64,
}
}
pub fn mk_mach_uint<'tcx>(tcx: &ctxt<'tcx>, tm: ast::UintTy) -> Ty<'tcx> {
match tm {
ast::TyU => tcx.types.uint,
ast::TyU8 => tcx.types.u8,
ast::TyU16 => tcx.types.u16,
ast::TyU32 => tcx.types.u32,
ast::TyU64 => tcx.types.u64,
}
}
pub fn mk_mach_float<'tcx>(tcx: &ctxt<'tcx>, tm: ast::FloatTy) -> Ty<'tcx> {
match tm {
ast::TyF32 => tcx.types.f32,
ast::TyF64 => tcx.types.f64,
}
}
pub fn mk_str<'tcx>(cx: &ctxt<'tcx>) -> Ty<'tcx> {
mk_t(cx, ty_str)
}
pub fn mk_str_slice<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, m: ast::Mutability) -> Ty<'tcx> {
mk_rptr(cx, r,
mt {
ty: mk_t(cx, ty_str),
mutbl: m
})
}
pub fn mk_enum<'tcx>(cx: &ctxt<'tcx>, did: ast::DefId, substs: &'tcx Substs<'tcx>) -> Ty<'tcx> {
// take a copy of substs so that we own the vectors inside
mk_t(cx, ty_enum(did, substs))
}
pub fn mk_uniq<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> { mk_t(cx, ty_uniq(ty)) }
pub fn mk_ptr<'tcx>(cx: &ctxt<'tcx>, tm: mt<'tcx>) -> Ty<'tcx> { mk_t(cx, ty_ptr(tm)) }
pub fn mk_rptr<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, tm: mt<'tcx>) -> Ty<'tcx> {
mk_t(cx, ty_rptr(r, tm))
}
pub fn mk_mut_rptr<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, ty: Ty<'tcx>) -> Ty<'tcx> {
mk_rptr(cx, r, mt {ty: ty, mutbl: ast::MutMutable})
}
pub fn mk_imm_rptr<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, ty: Ty<'tcx>) -> Ty<'tcx> {
mk_rptr(cx, r, mt {ty: ty, mutbl: ast::MutImmutable})
}
pub fn mk_mut_ptr<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
mk_ptr(cx, mt {ty: ty, mutbl: ast::MutMutable})
}
pub fn mk_imm_ptr<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
mk_ptr(cx, mt {ty: ty, mutbl: ast::MutImmutable})
}
pub fn mk_nil_ptr<'tcx>(cx: &ctxt<'tcx>) -> Ty<'tcx> {
mk_ptr(cx, mt {ty: mk_nil(cx), mutbl: ast::MutImmutable})
}
pub fn mk_vec<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>, sz: Option<uint>) -> Ty<'tcx> {
mk_t(cx, ty_vec(ty, sz))
}
pub fn mk_slice<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, tm: mt<'tcx>) -> Ty<'tcx> {
mk_rptr(cx, r,
mt {
ty: mk_vec(cx, tm.ty, None),
mutbl: tm.mutbl
})
}
pub fn mk_tup<'tcx>(cx: &ctxt<'tcx>, ts: Vec<Ty<'tcx>>) -> Ty<'tcx> {
mk_t(cx, ty_tup(ts))
}
pub fn mk_nil<'tcx>(cx: &ctxt<'tcx>) -> Ty<'tcx> {
mk_tup(cx, Vec::new())
}
pub fn mk_closure<'tcx>(cx: &ctxt<'tcx>, fty: ClosureTy<'tcx>) -> Ty<'tcx> {
mk_t(cx, ty_closure(box fty))
}
pub fn mk_bare_fn<'tcx>(cx: &ctxt<'tcx>,
opt_def_id: Option<ast::DefId>,
fty: &'tcx BareFnTy<'tcx>) -> Ty<'tcx> {
mk_t(cx, ty_bare_fn(opt_def_id, fty))
}
pub fn mk_ctor_fn<'tcx>(cx: &ctxt<'tcx>,
def_id: ast::DefId,
input_tys: &[Ty<'tcx>],
output: Ty<'tcx>) -> Ty<'tcx> {
let input_args = input_tys.iter().map(|ty| *ty).collect();
mk_bare_fn(cx,
Some(def_id),
cx.mk_bare_fn(BareFnTy {
unsafety: ast::Unsafety::Normal,
abi: abi::Rust,
sig: ty::Binder(FnSig {
inputs: input_args,
output: ty::FnConverging(output),
variadic: false
})
}))
}
pub fn mk_trait<'tcx>(cx: &ctxt<'tcx>,
principal: ty::PolyTraitRef<'tcx>,
bounds: ExistentialBounds<'tcx>)
-> Ty<'tcx>
{
assert!(bound_list_is_sorted(bounds.projection_bounds.as_slice()));
let inner = box TyTrait {
principal: principal,
bounds: bounds
};
mk_t(cx, ty_trait(inner))
}
fn bound_list_is_sorted(bounds: &[ty::PolyProjectionPredicate]) -> bool {
bounds.len() == 0 ||
bounds[1..].iter().enumerate().all(
|(index, bound)| bounds[index].sort_key() <= bound.sort_key())
}
pub fn sort_bounds_list(bounds: &mut [ty::PolyProjectionPredicate]) {
bounds.sort_by(|a, b| a.sort_key().cmp(&b.sort_key()))
}
pub fn mk_projection<'tcx>(cx: &ctxt<'tcx>,
trait_ref: Rc<ty::TraitRef<'tcx>>,
item_name: ast::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 };
mk_t(cx, ty_projection(inner))
}
pub fn mk_struct<'tcx>(cx: &ctxt<'tcx>, struct_id: ast::DefId,
substs: &'tcx Substs<'tcx>) -> Ty<'tcx> {
// take a copy of substs so that we own the vectors inside
mk_t(cx, ty_struct(struct_id, substs))
}
pub fn mk_unboxed_closure<'tcx>(cx: &ctxt<'tcx>, closure_id: ast::DefId,
region: &'tcx Region, substs: &'tcx Substs<'tcx>)
-> Ty<'tcx> {
mk_t(cx, ty_unboxed_closure(closure_id, region, substs))
}
pub fn mk_var<'tcx>(cx: &ctxt<'tcx>, v: TyVid) -> Ty<'tcx> {
mk_infer(cx, TyVar(v))
}
pub fn mk_int_var<'tcx>(cx: &ctxt<'tcx>, v: IntVid) -> Ty<'tcx> {
mk_infer(cx, IntVar(v))
}
pub fn mk_float_var<'tcx>(cx: &ctxt<'tcx>, v: FloatVid) -> Ty<'tcx> {
mk_infer(cx, FloatVar(v))
}
pub fn mk_infer<'tcx>(cx: &ctxt<'tcx>, it: InferTy) -> Ty<'tcx> {
mk_t(cx, ty_infer(it))
}
pub fn mk_param<'tcx>(cx: &ctxt<'tcx>,
space: subst::ParamSpace,
index: u32,
name: ast::Name) -> Ty<'tcx> {
mk_t(cx, ty_param(ParamTy { space: space, idx: index, name: name }))
}
pub fn mk_self_type<'tcx>(cx: &ctxt<'tcx>) -> Ty<'tcx> {
mk_param(cx, subst::SelfSpace, 0, special_idents::type_self.name)
}
pub fn mk_param_from_def<'tcx>(cx: &ctxt<'tcx>, def: &TypeParameterDef) -> Ty<'tcx> {
mk_param(cx, def.space, def.index, def.name)
}
pub fn mk_open<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> { mk_t(cx, ty_open(ty)) }
pub fn walk_ty<'tcx, F>(ty: Ty<'tcx>, mut f: F) where
F: FnMut(Ty<'tcx>),
{
maybe_walk_ty(ty, |ty| { f(ty); true });
}
pub fn maybe_walk_ty<'tcx, F>(ty: Ty<'tcx>, mut f: F) where F: FnMut(Ty<'tcx>) -> bool {
// FIXME(#19596) This is a workaround, but there should be a better way to do this
fn maybe_walk_ty_<'tcx, F>(ty: Ty<'tcx>, f: &mut F) where F: FnMut(Ty<'tcx>) -> bool {
if !(*f)(ty) {
return;
}
match ty.sty {
ty_bool | ty_char | ty_int(_) | ty_uint(_) | ty_float(_) |
ty_str | ty_infer(_) | ty_param(_) | ty_err => {}
ty_uniq(ty) | ty_vec(ty, _) | ty_open(ty) => maybe_walk_ty_(ty, f),
ty_ptr(ref tm) | ty_rptr(_, ref tm) => {
maybe_walk_ty_(tm.ty, f);
}
ty_trait(box TyTrait { ref principal, .. }) => {
for subty in principal.0.substs.types.iter() {
maybe_walk_ty_(*subty, f);
}
}
ty_projection(ProjectionTy { ref trait_ref, .. }) => {
for subty in trait_ref.substs.types.iter() {
maybe_walk_ty_(*subty, f);
}
}
ty_enum(_, ref substs) |
ty_struct(_, ref substs) |
ty_unboxed_closure(_, _, ref substs) => {
for subty in substs.types.iter() {
maybe_walk_ty_(*subty, f);
}
}
ty_tup(ref ts) => { for tt in ts.iter() { maybe_walk_ty_(*tt, f); } }
ty_bare_fn(_, ref ft) => {
for a in ft.sig.0.inputs.iter() { maybe_walk_ty_(*a, f); }
if let ty::FnConverging(output) = ft.sig.0.output {
maybe_walk_ty_(output, f);
}
}
ty_closure(ref ft) => {
for a in ft.sig.0.inputs.iter() { maybe_walk_ty_(*a, f); }
if let ty::FnConverging(output) = ft.sig.0.output {
maybe_walk_ty_(output, f);
}
}
}
}
maybe_walk_ty_(ty, &mut f);
}
// Folds types from the bottom up.
pub fn fold_ty<'tcx, F>(cx: &ctxt<'tcx>, t0: Ty<'tcx>,
fldop: F)
-> Ty<'tcx> where
F: FnMut(Ty<'tcx>) -> Ty<'tcx>,
{
let mut f = ty_fold::BottomUpFolder {tcx: cx, fldop: fldop};
f.fold_ty(t0)
}
impl ParamTy {
pub fn new(space: subst::ParamSpace,
index: u32,
name: ast::Name)
-> ParamTy {
ParamTy { space: space, idx: index, name: name }
}
pub fn for_self() -> ParamTy {
ParamTy::new(subst::SelfSpace, 0, special_idents::type_self.name)
}
pub fn for_def(def: &TypeParameterDef) -> ParamTy {
ParamTy::new(def.space, def.index, def.name)
}
pub fn to_ty<'tcx>(self, tcx: &ty::ctxt<'tcx>) -> Ty<'tcx> {
ty::mk_param(tcx, self.space, self.idx, self.name)
}
pub fn is_self(&self) -> bool {
self.space == subst::SelfSpace && self.idx == 0
}
}
impl<'tcx> ItemSubsts<'tcx> {
pub fn empty() -> ItemSubsts<'tcx> {
ItemSubsts { substs: Substs::empty() }
}
pub fn is_noop(&self) -> bool {
self.substs.is_noop()
}
}
impl<'tcx> ParamBounds<'tcx> {
pub fn empty() -> ParamBounds<'tcx> {
ParamBounds {
builtin_bounds: empty_builtin_bounds(),
trait_bounds: Vec::new(),
region_bounds: Vec::new(),
projection_bounds: Vec::new(),
}
}
}
// Type utilities
pub fn type_is_nil(ty: Ty) -> bool {
match ty.sty {
ty_tup(ref tys) => tys.is_empty(),
_ => false
}
}
pub fn type_is_error(ty: Ty) -> bool {
ty.flags.intersects(HAS_TY_ERR)
}
pub fn type_needs_subst(ty: Ty) -> bool {
ty.flags.intersects(NEEDS_SUBST)
}
pub fn trait_ref_contains_error(tref: &ty::TraitRef) -> bool {
tref.substs.types.any(|&ty| type_is_error(ty))
}
pub fn type_is_ty_var(ty: Ty) -> bool {
match ty.sty {
ty_infer(TyVar(_)) => true,
_ => false
}
}
pub fn type_is_bool(ty: Ty) -> bool { ty.sty == ty_bool }
pub fn type_is_self(ty: Ty) -> bool {
match ty.sty {
ty_param(ref p) => p.space == subst::SelfSpace,
_ => false
}
}
fn type_is_slice(ty: Ty) -> bool {
match ty.sty {
ty_ptr(mt) | ty_rptr(_, mt) => match mt.ty.sty {
ty_vec(_, None) | ty_str => true,
_ => false,
},
_ => false
}
}
pub fn type_is_vec(ty: Ty) -> bool {
match ty.sty {
ty_vec(..) => true,
ty_ptr(mt{ty, ..}) | ty_rptr(_, mt{ty, ..}) |
ty_uniq(ty) => match ty.sty {
ty_vec(_, None) => true,
_ => false
},
_ => false
}
}
pub fn type_is_structural(ty: Ty) -> bool {
match ty.sty {
ty_struct(..) | ty_tup(_) | ty_enum(..) | ty_closure(_) |
ty_vec(_, Some(_)) | ty_unboxed_closure(..) => true,
_ => type_is_slice(ty) | type_is_trait(ty)
}
}
pub fn type_is_simd(cx: &ctxt, ty: Ty) -> bool {
match ty.sty {
ty_struct(did, _) => lookup_simd(cx, did),
_ => false
}
}
pub fn sequence_element_type<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
match ty.sty {
ty_vec(ty, _) => ty,
ty_str => mk_mach_uint(cx, ast::TyU8),
ty_open(ty) => sequence_element_type(cx, ty),
_ => cx.sess.bug(format!("sequence_element_type called on non-sequence value: {}",
ty_to_string(cx, ty))[]),
}
}
pub fn simd_type<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
match ty.sty {
ty_struct(did, substs) => {
let fields = lookup_struct_fields(cx, did);
lookup_field_type(cx, did, fields[0].id, substs)
}
_ => panic!("simd_type called on invalid type")
}
}
pub fn simd_size(cx: &ctxt, ty: Ty) -> uint {
match ty.sty {
ty_struct(did, _) => {
let fields = lookup_struct_fields(cx, did);
fields.len()
}
_ => panic!("simd_size called on invalid type")
}
}
pub fn type_is_region_ptr(ty: Ty) -> bool {
match ty.sty {
ty_rptr(..) => true,
_ => false
}
}
pub fn type_is_unsafe_ptr(ty: Ty) -> bool {
match ty.sty {
ty_ptr(_) => return true,
_ => return false
}
}
pub fn type_is_unique(ty: Ty) -> bool {
match ty.sty {
ty_uniq(_) => match ty.sty {
ty_trait(..) => false,
_ => true
},
_ => false
}
}
/*
A scalar type is one that denotes an atomic datum, with no sub-components.
(A ty_ptr is scalar because it represents a non-managed pointer, so its
contents are abstract to rustc.)
*/
pub fn type_is_scalar(ty: Ty) -> bool {
match ty.sty {
ty_bool | ty_char | ty_int(_) | ty_float(_) | ty_uint(_) |
ty_infer(IntVar(_)) | ty_infer(FloatVar(_)) |
ty_bare_fn(..) | ty_ptr(_) => true,
ty_tup(ref tys) if tys.is_empty() => true,
_ => false
}
}
/// Returns true if this type is a floating point type and false otherwise.
pub fn type_is_floating_point(ty: Ty) -> bool {
match ty.sty {
ty_float(_) => true,
_ => false,
}
}
/// Type contents is how the type checker reasons about kinds.
/// They track what kinds of things are found within a type. You can
/// think of them as kind of an "anti-kind". They track the kinds of values
/// and thinks that are contained in types. Having a larger contents for
/// a type tends to rule that type *out* from various kinds. For example,
/// a type that contains a reference is not sendable.
///
/// The reason we compute type contents and not kinds is that it is
/// easier for me (nmatsakis) to think about what is contained within
/// a type than to think about what is *not* contained within a type.
#[deriving(Clone, Copy)]
pub struct TypeContents {
pub bits: u64
}
macro_rules! def_type_content_sets {
(mod $mname:ident { $($name:ident = $bits:expr),+ }) => {
#[allow(non_snake_case)]
mod $mname {
use middle::ty::TypeContents;
$(
#[allow(non_upper_case_globals)]
pub const $name: TypeContents = TypeContents { bits: $bits };
)+
}
}
}
def_type_content_sets! {
mod TC {
None = 0b0000_0000__0000_0000__0000,
// Things that are interior to the value (first nibble):
InteriorUnsized = 0b0000_0000__0000_0000__0001,
InteriorUnsafe = 0b0000_0000__0000_0000__0010,
InteriorParam = 0b0000_0000__0000_0000__0100,
// InteriorAll = 0b00000000__00000000__1111,
// Things that are owned by the value (second and third nibbles):
OwnsOwned = 0b0000_0000__0000_0001__0000,
OwnsDtor = 0b0000_0000__0000_0010__0000,
OwnsManaged /* see [1] below */ = 0b0000_0000__0000_0100__0000,
OwnsAll = 0b0000_0000__1111_1111__0000,
// Things that are reachable by the value in any way (fourth nibble):
ReachesBorrowed = 0b0000_0010__0000_0000__0000,
// ReachesManaged /* see [1] below */ = 0b0000_0100__0000_0000__0000,
ReachesMutable = 0b0000_1000__0000_0000__0000,
ReachesFfiUnsafe = 0b0010_0000__0000_0000__0000,
ReachesAll = 0b0011_1111__0000_0000__0000,
// Things that mean drop glue is necessary
NeedsDrop = 0b0000_0000__0000_0111__0000,
// Things that prevent values from being considered sized
Nonsized = 0b0000_0000__0000_0000__0001,
// Bits to set when a managed value is encountered
//
// [1] Do not set the bits TC::OwnsManaged or
// TC::ReachesManaged directly, instead reference
// TC::Managed to set them both at once.
Managed = 0b0000_0100__0000_0100__0000,
// All bits
All = 0b1111_1111__1111_1111__1111
}
}
impl TypeContents {
pub fn when(&self, cond: bool) -> TypeContents {
if cond {*self} else {TC::None}
}
pub fn intersects(&self, tc: TypeContents) -> bool {
(self.bits & tc.bits) != 0
}
pub fn owns_managed(&self) -> bool {
self.intersects(TC::OwnsManaged)
}
pub fn owns_owned(&self) -> bool {
self.intersects(TC::OwnsOwned)
}
pub fn is_sized(&self, _: &ctxt) -> bool {
!self.intersects(TC::Nonsized)
}
pub fn interior_param(&self) -> bool {
self.intersects(TC::InteriorParam)
}
pub fn interior_unsafe(&self) -> bool {
self.intersects(TC::InteriorUnsafe)
}
pub fn interior_unsized(&self) -> bool {
self.intersects(TC::InteriorUnsized)
}
pub fn needs_drop(&self, _: &ctxt) -> bool {
self.intersects(TC::NeedsDrop)
}
/// Includes only those bits that still apply when indirected through a `Box` pointer
pub fn owned_pointer(&self) -> TypeContents {
TC::OwnsOwned | (
*self & (TC::OwnsAll | TC::ReachesAll))
}
/// Includes only those bits that still apply when indirected through a reference (`&`)
pub fn reference(&self, bits: TypeContents) -> TypeContents {
bits | (
*self & TC::ReachesAll)
}
/// Includes only those bits that still apply when indirected through a managed pointer (`@`)
pub fn managed_pointer(&self) -> TypeContents {
TC::Managed | (
*self & TC::ReachesAll)
}
/// Includes only those bits that still apply when indirected through an unsafe pointer (`*`)
pub fn unsafe_pointer(&self) -> TypeContents {
*self & TC::ReachesAll
}
pub fn union<T, F>(v: &[T], mut f: F) -> TypeContents where
F: FnMut(&T) -> TypeContents,
{
v.iter().fold(TC::None, |tc, ty| tc | f(ty))
}
pub fn has_dtor(&self) -> bool {
self.intersects(TC::OwnsDtor)
}
}
impl ops::BitOr<TypeContents,TypeContents> for TypeContents {
fn bitor(self, other: TypeContents) -> TypeContents {
TypeContents {bits: self.bits | other.bits}
}
}
impl ops::BitAnd<TypeContents, TypeContents> for TypeContents {
fn bitand(self, other: TypeContents) -> TypeContents {
TypeContents {bits: self.bits & other.bits}
}
}
impl ops::Sub<TypeContents, TypeContents> for TypeContents {
fn sub(self, other: TypeContents) -> TypeContents {
TypeContents {bits: self.bits & !other.bits}
}
}
impl fmt::Show for TypeContents {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "TypeContents({:b})", self.bits)
}
}
pub fn type_interior_is_unsafe<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> bool {
type_contents(cx, ty).interior_unsafe()
}
pub fn type_contents<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> TypeContents {
return memoized(&cx.tc_cache, ty, |ty| {
tc_ty(cx, ty, &mut FnvHashMap::new())
});
fn tc_ty<'tcx>(cx: &ctxt<'tcx>,
ty: Ty<'tcx>,
cache: &mut FnvHashMap<Ty<'tcx>, TypeContents>) -> TypeContents
{
// Subtle: Note that we are *not* using cx.tc_cache here but rather a
// private cache for this walk. This is needed in the case of cyclic
// types like:
//
// struct List { next: Box<Option<List>>, ... }
//
// When computing the type contents of such a type, we wind up deeply
// recursing as we go. So when we encounter the recursive reference
// to List, we temporarily use TC::None as its contents. Later we'll
// patch up the cache with the correct value, once we've computed it
// (this is basically a co-inductive process, if that helps). So in
// the end we'll compute TC::OwnsOwned, in this case.
//
// The problem is, as we are doing the computation, we will also
// compute an *intermediate* contents for, e.g., Option<List> of
// TC::None. This is ok during the computation of List itself, but if
// we stored this intermediate value into cx.tc_cache, then later
// requests for the contents of Option<List> would also yield TC::None
// which is incorrect. This value was computed based on the crutch
// value for the type contents of list. The correct value is
// TC::OwnsOwned. This manifested as issue #4821.
match cache.get(&ty) {
Some(tc) => { return *tc; }
None => {}
}
match cx.tc_cache.borrow().get(&ty) { // Must check both caches!
Some(tc) => { return *tc; }
None => {}
}
cache.insert(ty, TC::None);
let result = match ty.sty {
// uint and int are ffi-unsafe
ty_uint(ast::TyU) | ty_int(ast::TyI) => {
TC::ReachesFfiUnsafe
}
// Scalar and unique types are sendable, and durable
ty_infer(ty::FreshIntTy(_)) |
ty_bool | ty_int(_) | ty_uint(_) | ty_float(_) |
ty_bare_fn(..) | ty::ty_char => {
TC::None
}
ty_closure(ref c) => {
closure_contents(&**c) | TC::ReachesFfiUnsafe
}
ty_uniq(typ) => {
TC::ReachesFfiUnsafe | match typ.sty {
ty_str => TC::OwnsOwned,
_ => tc_ty(cx, typ, cache).owned_pointer(),
}
}
ty_trait(box TyTrait { ref bounds, .. }) => {
object_contents(bounds) | TC::ReachesFfiUnsafe | TC::Nonsized
}
ty_ptr(ref mt) => {
tc_ty(cx, mt.ty, cache).unsafe_pointer()
}
ty_rptr(r, ref mt) => {
TC::ReachesFfiUnsafe | match mt.ty.sty {
ty_str => borrowed_contents(*r, ast::MutImmutable),
ty_vec(..) => tc_ty(cx, mt.ty, cache).reference(borrowed_contents(*r,
mt.mutbl)),
_ => tc_ty(cx, mt.ty, cache).reference(borrowed_contents(*r, mt.mutbl)),
}
}
ty_vec(ty, Some(_)) => {
tc_ty(cx, ty, cache)
}
ty_vec(ty, None) => {
tc_ty(cx, ty, cache) | TC::Nonsized
}
ty_str => TC::Nonsized,
ty_struct(did, substs) => {
let flds = struct_fields(cx, did, substs);
let mut res =
TypeContents::union(flds[],
|f| tc_mt(cx, f.mt, cache));
if !lookup_repr_hints(cx, did).contains(&attr::ReprExtern) {
res = res | TC::ReachesFfiUnsafe;
}
if ty::has_dtor(cx, did) {
res = res | TC::OwnsDtor;
}
apply_lang_items(cx, did, res)
}
ty_unboxed_closure(did, r, substs) => {
// FIXME(#14449): `borrowed_contents` below assumes `&mut`
// unboxed closure.
let upvars = unboxed_closure_upvars(cx, did, substs).unwrap();
TypeContents::union(upvars.as_slice(),
|f| tc_ty(cx, f.ty, cache))
| borrowed_contents(*r, MutMutable)
}
ty_tup(ref tys) => {
TypeContents::union(tys[],
|ty| tc_ty(cx, *ty, cache))
}
ty_enum(did, substs) => {
let variants = substd_enum_variants(cx, did, substs);
let mut res =
TypeContents::union(variants[], |variant| {
TypeContents::union(variant.args[],
|arg_ty| {
tc_ty(cx, *arg_ty, cache)
})
});
if ty::has_dtor(cx, did) {
res = res | TC::OwnsDtor;
}
if variants.len() != 0 {
let repr_hints = lookup_repr_hints(cx, did);
if repr_hints.len() > 1 {
// this is an error later on, but this type isn't safe
res = res | TC::ReachesFfiUnsafe;
}
match repr_hints.get(0) {
Some(h) => if !h.is_ffi_safe() {
res = res | TC::ReachesFfiUnsafe;
},
// ReprAny
None => {
res = res | TC::ReachesFfiUnsafe;
// We allow ReprAny enums if they are eligible for
// the nullable pointer optimization and the
// contained type is an `extern fn`
if variants.len() == 2 {
let mut data_idx = 0;
if variants[0].args.len() == 0 {
data_idx = 1;
}
if variants[data_idx].args.len() == 1 {
match variants[data_idx].args[0].sty {
ty_bare_fn(..) => { res = res - TC::ReachesFfiUnsafe; }
_ => { }
}
}
}
}
}
}
apply_lang_items(cx, did, res)
}
ty_projection(..) |
ty_param(_) => {
TC::All
}
ty_open(ty) => {
let result = tc_ty(cx, ty, cache);
assert!(!result.is_sized(cx));
result.unsafe_pointer() | TC::Nonsized
}
ty_infer(_) |
ty_err => {
cx.sess.bug("asked to compute contents of error type");
}
};
cache.insert(ty, result);
result
}
fn tc_mt<'tcx>(cx: &ctxt<'tcx>,
mt: mt<'tcx>,
cache: &mut FnvHashMap<Ty<'tcx>, TypeContents>) -> TypeContents
{
let mc = TC::ReachesMutable.when(mt.mutbl == MutMutable);
mc | tc_ty(cx, mt.ty, cache)
}
fn apply_lang_items(cx: &ctxt, did: ast::DefId, tc: TypeContents)
-> TypeContents {
if Some(did) == cx.lang_items.managed_bound() {
tc | TC::Managed
} else if Some(did) == cx.lang_items.unsafe_type() {
tc | TC::InteriorUnsafe
} else {
tc
}
}
/// Type contents due to containing a reference with the region `region` and borrow kind `bk`
fn borrowed_contents(region: ty::Region,
mutbl: ast::Mutability)
-> TypeContents {
let b = match mutbl {
ast::MutMutable => TC::ReachesMutable,
ast::MutImmutable => TC::None,
};
b | (TC::ReachesBorrowed).when(region != ty::ReStatic)
}
fn closure_contents(cty: &ClosureTy) -> TypeContents {
// Closure contents are just like trait contents, but with potentially
// even more stuff.
let st = object_contents(&cty.bounds);
let st = match cty.store {
UniqTraitStore => {
st.owned_pointer()
}
RegionTraitStore(r, mutbl) => {
st.reference(borrowed_contents(r, mutbl))
}
};
st
}
fn object_contents(bounds: &ExistentialBounds) -> TypeContents {
// These are the type contents of the (opaque) interior. We
// make no assumptions (other than that it cannot have an
// in-scope type parameter within, which makes no sense).
let mut tc = TC::All - TC::InteriorParam;
for bound in bounds.builtin_bounds.iter() {
tc = tc - match bound {
BoundSync | BoundSend | BoundCopy => TC::None,
BoundSized => TC::Nonsized,
};
}
return tc;
}
}
fn type_impls_bound<'tcx>(cx: &ctxt<'tcx>,
cache: &RefCell<HashMap<Ty<'tcx>,bool>>,
param_env: &ParameterEnvironment<'tcx>,
ty: Ty<'tcx>,
bound: ty::BuiltinBound)
-> bool
{
assert!(!ty::type_needs_infer(ty));
if !type_has_params(ty) && !type_has_self(ty) {
match cache.borrow().get(&ty) {
None => {}
Some(&result) => {
debug!("type_impls_bound({}, {}) = {} (cached)",
ty_to_string(cx, ty),
bound,
result);
return result
}
}
}
let infcx = infer::new_infer_ctxt(cx);
let is_impld = traits::type_known_to_meet_builtin_bound(&infcx, param_env, ty, bound);
debug!("type_impls_bound({}, {}) = {}",
ty_to_string(cx, ty),
bound,
is_impld);
if !type_has_params(ty) && !type_has_self(ty) {
let old_value = cache.borrow_mut().insert(ty, is_impld);
assert!(old_value.is_none());
}
is_impld
}
pub fn type_moves_by_default<'tcx>(cx: &ctxt<'tcx>,
ty: Ty<'tcx>,
param_env: &ParameterEnvironment<'tcx>)
-> bool
{
!type_impls_bound(cx, &cx.type_impls_copy_cache, param_env, ty, ty::BoundCopy)
}
pub fn type_is_sized<'tcx>(cx: &ctxt<'tcx>,
ty: Ty<'tcx>,
param_env: &ParameterEnvironment<'tcx>)
-> bool
{
type_impls_bound(cx, &cx.type_impls_sized_cache, param_env, ty, ty::BoundSized)
}
pub fn is_ffi_safe<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> bool {
!type_contents(cx, ty).intersects(TC::ReachesFfiUnsafe)
}
// True if instantiating an instance of `r_ty` requires an instance of `r_ty`.
pub fn is_instantiable<'tcx>(cx: &ctxt<'tcx>, r_ty: Ty<'tcx>) -> bool {
fn type_requires<'tcx>(cx: &ctxt<'tcx>, seen: &mut Vec<DefId>,
r_ty: Ty<'tcx>, ty: Ty<'tcx>) -> bool {
debug!("type_requires({}, {})?",
::util::ppaux::ty_to_string(cx, r_ty),
::util::ppaux::ty_to_string(cx, ty));
let r = r_ty == ty || subtypes_require(cx, seen, r_ty, ty);
debug!("type_requires({}, {})? {}",
::util::ppaux::ty_to_string(cx, r_ty),
::util::ppaux::ty_to_string(cx, ty),
r);
return r;
}
fn subtypes_require<'tcx>(cx: &ctxt<'tcx>, seen: &mut Vec<DefId>,
r_ty: Ty<'tcx>, ty: Ty<'tcx>) -> bool {
debug!("subtypes_require({}, {})?",
::util::ppaux::ty_to_string(cx, r_ty),
::util::ppaux::ty_to_string(cx, ty));
let r = match ty.sty {
// fixed length vectors need special treatment compared to
// normal vectors, since they don't necessarily have the
// possibility to have length zero.
ty_vec(_, Some(0)) => false, // don't need no contents
ty_vec(ty, Some(_)) => type_requires(cx, seen, r_ty, ty),
ty_bool |
ty_char |
ty_int(_) |
ty_uint(_) |
ty_float(_) |
ty_str |
ty_bare_fn(..) |
ty_closure(_) |
ty_infer(_) |
ty_err |
ty_param(_) |
ty_projection(_) |
ty_vec(_, None) => {
false
}
ty_uniq(typ) | ty_open(typ) => {
type_requires(cx, seen, r_ty, typ)
}
ty_rptr(_, ref mt) => {
type_requires(cx, seen, r_ty, mt.ty)
}
ty_ptr(..) => {
false // unsafe ptrs can always be NULL
}
ty_trait(..) => {
false
}
ty_struct(ref did, _) if seen.contains(did) => {
false
}
ty_struct(did, substs) => {
seen.push(did);
let fields = struct_fields(cx, did, substs);
let r = fields.iter().any(|f| type_requires(cx, seen, r_ty, f.mt.ty));
seen.pop().unwrap();
r
}
ty_unboxed_closure(did, _, substs) => {
let upvars = unboxed_closure_upvars(cx, did, substs).unwrap();
upvars.iter().any(|f| type_requires(cx, seen, r_ty, f.ty))
}
ty_tup(ref ts) => {
ts.iter().any(|ty| type_requires(cx, seen, r_ty, *ty))
}
ty_enum(ref did, _) if seen.contains(did) => {
false
}
ty_enum(did, substs) => {
seen.push(did);
let vs = enum_variants(cx, did);
let r = !vs.is_empty() && vs.iter().all(|variant| {
variant.args.iter().any(|aty| {
let sty = aty.subst(cx, substs);
type_requires(cx, seen, r_ty, sty)
})
});
seen.pop().unwrap();
r
}
};
debug!("subtypes_require({}, {})? {}",
::util::ppaux::ty_to_string(cx, r_ty),
::util::ppaux::ty_to_string(cx, ty),
r);
return r;
}
let mut seen = Vec::new();
!subtypes_require(cx, &mut seen, r_ty, r_ty)
}
/// Describes whether a type is representable. For types that are not
/// representable, 'SelfRecursive' and 'ContainsRecursive' are used to
/// distinguish between types that are recursive with themselves and types that
/// contain a different recursive type. These cases can therefore be treated
/// differently when reporting errors.
///
/// The ordering of the cases is significant. They are sorted so that cmp::max
/// will keep the "more erroneous" of two values.
#[deriving(Copy, PartialOrd, Ord, Eq, PartialEq, Show)]
pub enum Representability {
Representable,
ContainsRecursive,
SelfRecursive,
}
/// Check whether a type is representable. This means it cannot contain unboxed
/// structural recursion. This check is needed for structs and enums.
pub fn is_type_representable<'tcx>(cx: &ctxt<'tcx>, sp: Span, ty: Ty<'tcx>)
-> Representability {
// Iterate until something non-representable is found
fn find_nonrepresentable<'tcx, It: Iterator<Ty<'tcx>>>(cx: &ctxt<'tcx>, sp: Span,
seen: &mut Vec<Ty<'tcx>>,
iter: It)
-> Representability {
iter.fold(Representable,
|r, ty| cmp::max(r, is_type_structurally_recursive(cx, sp, seen, ty)))
}
fn are_inner_types_recursive<'tcx>(cx: &ctxt<'tcx>, sp: Span,
seen: &mut Vec<Ty<'tcx>>, ty: Ty<'tcx>)
-> Representability {
match ty.sty {
ty_tup(ref ts) => {
find_nonrepresentable(cx, sp, seen, ts.iter().map(|ty| *ty))
}
// Fixed-length vectors.
// FIXME(#11924) Behavior undecided for zero-length vectors.
ty_vec(ty, Some(_)) => {
is_type_structurally_recursive(cx, sp, seen, ty)
}
ty_struct(did, substs) => {
let fields = struct_fields(cx, did, substs);
find_nonrepresentable(cx, sp, seen, fields.iter().map(|f| f.mt.ty))
}
ty_enum(did, substs) => {
let vs = enum_variants(cx, did);
let iter = vs.iter()
.flat_map(|variant| { variant.args.iter() })
.map(|aty| { aty.subst_spanned(cx, substs, Some(sp)) });
find_nonrepresentable(cx, sp, seen, iter)
}
ty_unboxed_closure(did, _, substs) => {
let upvars = unboxed_closure_upvars(cx, did, substs).unwrap();
find_nonrepresentable(cx, sp, seen, upvars.iter().map(|f| f.ty))
}
_ => Representable,
}
}
fn same_struct_or_enum_def_id(ty: Ty, did: DefId) -> bool {
match ty.sty {
ty_struct(ty_did, _) | ty_enum(ty_did, _) => {
ty_did == did
}
_ => false
}
}
fn same_type<'tcx>(a: Ty<'tcx>, b: Ty<'tcx>) -> bool {
match (&a.sty, &b.sty) {
(&ty_struct(did_a, ref substs_a), &ty_struct(did_b, ref substs_b)) |
(&ty_enum(did_a, ref substs_a), &ty_enum(did_b, ref substs_b)) => {
if did_a != did_b {
return false;
}
let types_a = substs_a.types.get_slice(subst::TypeSpace);
let types_b = substs_b.types.get_slice(subst::TypeSpace);
let pairs = types_a.iter().zip(types_b.iter());
pairs.all(|(&a, &b)| same_type(a, b))
}
_ => {
a == b
}
}
}
// Does the type `ty` directly (without indirection through a pointer)
// contain any types on stack `seen`?
fn is_type_structurally_recursive<'tcx>(cx: &ctxt<'tcx>, sp: Span,
seen: &mut Vec<Ty<'tcx>>,
ty: Ty<'tcx>) -> Representability {
debug!("is_type_structurally_recursive: {}",
::util::ppaux::ty_to_string(cx, ty));
match ty.sty {
ty_struct(did, _) | ty_enum(did, _) => {
{
// Iterate through stack of previously seen types.
let mut iter = seen.iter();
// The first item in `seen` is the type we are actually curious about.
// We want to return SelfRecursive if this type contains itself.
// It is important that we DON'T take generic parameters into account
// for this check, so that Bar<T> in this example counts as SelfRecursive:
//
// struct Foo;
// struct Bar<T> { x: Bar<Foo> }
match iter.next() {
Some(&seen_type) => {
if same_struct_or_enum_def_id(seen_type, did) {
debug!("SelfRecursive: {} contains {}",
::util::ppaux::ty_to_string(cx, seen_type),
::util::ppaux::ty_to_string(cx, ty));
return SelfRecursive;
}
}
None => {}
}
// We also need to know whether the first item contains other types that
// are structurally recursive. If we don't catch this case, we will recurse
// infinitely for some inputs.
//
// It is important that we DO take generic parameters into account here,
// so that code like this is considered SelfRecursive, not ContainsRecursive:
//
// struct Foo { Option<Option<Foo>> }
for &seen_type in iter {
if same_type(ty, seen_type) {
debug!("ContainsRecursive: {} contains {}",
::util::ppaux::ty_to_string(cx, seen_type),
::util::ppaux::ty_to_string(cx, ty));
return ContainsRecursive;
}
}
}
// For structs and enums, track all previously seen types by pushing them
// onto the 'seen' stack.
seen.push(ty);
let out = are_inner_types_recursive(cx, sp, seen, ty);
seen.pop();
out
}
_ => {
// No need to push in other cases.
are_inner_types_recursive(cx, sp, seen, ty)
}
}
}
debug!("is_type_representable: {}",
::util::ppaux::ty_to_string(cx, ty));
// To avoid a stack overflow when checking an enum variant or struct that
// contains a different, structurally recursive type, maintain a stack
// of seen types and check recursion for each of them (issues #3008, #3779).
let mut seen: Vec<Ty> = Vec::new();
let r = is_type_structurally_recursive(cx, sp, &mut seen, ty);
debug!("is_type_representable: {} is {}",
::util::ppaux::ty_to_string(cx, ty), r);
r
}
pub fn type_is_trait(ty: Ty) -> bool {
type_trait_info(ty).is_some()
}
pub fn type_trait_info<'tcx>(ty: Ty<'tcx>) -> Option<&'tcx TyTrait<'tcx>> {
match ty.sty {
ty_uniq(ty) | ty_rptr(_, mt { ty, ..}) | ty_ptr(mt { ty, ..}) => match ty.sty {
ty_trait(ref t) => Some(&**t),
_ => None
},
ty_trait(ref t) => Some(&**t),
_ => None
}
}
pub fn type_is_integral(ty: Ty) -> bool {
match ty.sty {
ty_infer(IntVar(_)) | ty_int(_) | ty_uint(_) => true,
_ => false
}
}
pub fn type_is_fresh(ty: Ty) -> bool {
match ty.sty {
ty_infer(FreshTy(_)) => true,
ty_infer(FreshIntTy(_)) => true,
_ => false
}
}
pub fn type_is_uint(ty: Ty) -> bool {
match ty.sty {
ty_infer(IntVar(_)) | ty_uint(ast::TyU) => true,
_ => false
}
}
pub fn type_is_char(ty: Ty) -> bool {
match ty.sty {
ty_char => true,
_ => false
}
}
pub fn type_is_bare_fn(ty: Ty) -> bool {
match ty.sty {
ty_bare_fn(..) => true,
_ => false
}
}
pub fn type_is_bare_fn_item(ty: Ty) -> bool {
match ty.sty {
ty_bare_fn(Some(_), _) => true,
_ => false
}
}
pub fn type_is_fp(ty: Ty) -> bool {
match ty.sty {
ty_infer(FloatVar(_)) | ty_float(_) => true,
_ => false
}
}
pub fn type_is_numeric(ty: Ty) -> bool {
return type_is_integral(ty) || type_is_fp(ty);
}
pub fn type_is_signed(ty: Ty) -> bool {
match ty.sty {
ty_int(_) => true,
_ => false
}
}
pub fn type_is_machine(ty: Ty) -> bool {
match ty.sty {
ty_int(ast::TyI) | ty_uint(ast::TyU) => false,
ty_int(..) | ty_uint(..) | ty_float(..) => true,
_ => false
}
}
// Whether a type is enum like, that is an enum type with only nullary
// constructors
pub fn type_is_c_like_enum(cx: &ctxt, ty: Ty) -> bool {
match ty.sty {
ty_enum(did, _) => {
let variants = enum_variants(cx, did);
if variants.len() == 0 {
false
} else {
variants.iter().all(|v| v.args.len() == 0)
}
}
_ => false
}
}
// Returns the type and mutability of *ty.
//
// The parameter `explicit` indicates if this is an *explicit* dereference.
// Some types---notably unsafe ptrs---can only be dereferenced explicitly.
pub fn deref<'tcx>(ty: Ty<'tcx>, explicit: bool) -> Option<mt<'tcx>> {
match ty.sty {
ty_uniq(ty) => {
Some(mt {
ty: ty,
mutbl: ast::MutImmutable,
})
},
ty_rptr(_, mt) => Some(mt),
ty_ptr(mt) if explicit => Some(mt),
_ => None
}
}
pub fn close_type<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
match ty.sty {
ty_open(ty) => mk_rptr(cx, cx.mk_region(ReStatic), mt {ty: ty, mutbl:ast::MutImmutable}),
_ => cx.sess.bug(format!("Trying to close a non-open type {}",
ty_to_string(cx, ty))[])
}
}
pub fn type_content<'tcx>(ty: Ty<'tcx>) -> Ty<'tcx> {
match ty.sty {
ty_uniq(ty) => ty,
ty_rptr(_, mt) |ty_ptr(mt) => mt.ty,
_ => ty
}
}
// Extract the unsized type in an open type (or just return ty if it is not open).
pub fn unopen_type<'tcx>(ty: Ty<'tcx>) -> Ty<'tcx> {
match ty.sty {
ty_open(ty) => ty,
_ => ty
}
}
// Returns the type of ty[i]
pub fn index<'tcx>(ty: Ty<'tcx>) -> Option<Ty<'tcx>> {
match ty.sty {
ty_vec(ty, _) => Some(ty),
_ => None
}
}
// Returns the type of elements contained within an 'array-like' type.
// This is exactly the same as the above, except it supports strings,
// which can't actually be indexed.
pub fn array_element_ty<'tcx>(tcx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Option<Ty<'tcx>> {
match ty.sty {
ty_vec(ty, _) => Some(ty),
ty_str => Some(tcx.types.u8),
_ => None
}
}
/// Returns the type of element at index `i` in tuple or tuple-like type `t`.
/// For an enum `t`, `variant` is None only if `t` is a univariant enum.
pub fn positional_element_ty<'tcx>(cx: &ctxt<'tcx>,
ty: Ty<'tcx>,
i: uint,
variant: Option<ast::DefId>) -> Option<Ty<'tcx>> {
match (&ty.sty, variant) {
(&ty_tup(ref v), None) => v.get(i).map(|&t| t),
(&ty_struct(def_id, substs), None) => lookup_struct_fields(cx, def_id)
.get(i)
.map(|&t|lookup_item_type(cx, t.id).ty.subst(cx, substs)),
(&ty_enum(def_id, substs), Some(variant_def_id)) => {
let variant_info = enum_variant_with_id(cx, def_id, variant_def_id);
variant_info.args.get(i).map(|t|t.subst(cx, substs))
}
(&ty_enum(def_id, substs), None) => {
assert!(enum_is_univariant(cx, def_id));
let enum_variants = enum_variants(cx, def_id);
let variant_info = &(*enum_variants)[0];
variant_info.args.get(i).map(|t|t.subst(cx, substs))
}
_ => None
}
}
/// Returns the type of element at field `n` in struct or struct-like type `t`.
/// For an enum `t`, `variant` must be some def id.
pub fn named_element_ty<'tcx>(cx: &ctxt<'tcx>,
ty: Ty<'tcx>,
n: ast::Name,
variant: Option<ast::DefId>) -> Option<Ty<'tcx>> {
match (&ty.sty, variant) {
(&ty_struct(def_id, substs), None) => {
let r = lookup_struct_fields(cx, def_id);
r.iter().find(|f| f.name == n)
.map(|&f| lookup_field_type(cx, def_id, f.id, substs))
}
(&ty_enum(def_id, substs), Some(variant_def_id)) => {
let variant_info = enum_variant_with_id(cx, def_id, variant_def_id);
variant_info.arg_names.as_ref()
.expect("must have struct enum variant if accessing a named fields")
.iter().zip(variant_info.args.iter())
.find(|&(ident, _)| ident.name == n)
.map(|(_ident, arg_t)| arg_t.subst(cx, substs))
}
_ => None
}
}
pub fn node_id_to_trait_ref<'tcx>(cx: &ctxt<'tcx>, id: ast::NodeId)
-> Rc<ty::TraitRef<'tcx>> {
match cx.trait_refs.borrow().get(&id) {
Some(ty) => ty.clone(),
None => cx.sess.bug(
format!("node_id_to_trait_ref: no trait ref for node `{}`",
cx.map.node_to_string(id))[])
}
}
pub fn try_node_id_to_type<'tcx>(cx: &ctxt<'tcx>, id: ast::NodeId) -> Option<Ty<'tcx>> {
cx.node_types.borrow().get(&id).cloned()
}
pub fn node_id_to_type<'tcx>(cx: &ctxt<'tcx>, id: ast::NodeId) -> Ty<'tcx> {
match try_node_id_to_type(cx, id) {
Some(ty) => ty,
None => cx.sess.bug(
format!("node_id_to_type: no type for node `{}`",
cx.map.node_to_string(id))[])
}
}
pub fn node_id_to_type_opt<'tcx>(cx: &ctxt<'tcx>, id: ast::NodeId) -> Option<Ty<'tcx>> {
match cx.node_types.borrow().get(&id) {
Some(&ty) => Some(ty),
None => None
}
}
pub fn node_id_item_substs<'tcx>(cx: &ctxt<'tcx>, id: ast::NodeId) -> ItemSubsts<'tcx> {
match cx.item_substs.borrow().get(&id) {
None => ItemSubsts::empty(),
Some(ts) => ts.clone(),
}
}
pub fn fn_is_variadic(fty: Ty) -> bool {
match fty.sty {
ty_bare_fn(_, ref f) => f.sig.0.variadic,
ty_closure(ref f) => f.sig.0.variadic,
ref s => {
panic!("fn_is_variadic() called on non-fn type: {}", s)
}
}
}
pub fn ty_fn_sig<'tcx>(fty: Ty<'tcx>) -> &'tcx PolyFnSig<'tcx> {
match fty.sty {
ty_bare_fn(_, ref f) => &f.sig,
ty_closure(ref f) => &f.sig,
ref s => {
panic!("ty_fn_sig() called on non-fn type: {}", s)
}
}
}
/// Returns the ABI of the given function.
pub fn ty_fn_abi(fty: Ty) -> abi::Abi {
match fty.sty {
ty_bare_fn(_, ref f) => f.abi,
ty_closure(ref f) => f.abi,
_ => panic!("ty_fn_abi() called on non-fn type"),
}
}
// Type accessors for substructures of types
pub fn ty_fn_args<'tcx>(fty: Ty<'tcx>) -> &'tcx [Ty<'tcx>] {
ty_fn_sig(fty).0.inputs.as_slice()
}
pub fn ty_closure_store(fty: Ty) -> TraitStore {
match fty.sty {
ty_closure(ref f) => f.store,
ty_unboxed_closure(..) => {
// Close enough for the purposes of all the callers of this
// function (which is soon to be deprecated anyhow).
UniqTraitStore
}
ref s => {
panic!("ty_closure_store() called on non-closure type: {}", s)
}
}
}
pub fn ty_fn_ret<'tcx>(fty: Ty<'tcx>) -> FnOutput<'tcx> {
match fty.sty {
ty_bare_fn(_, ref f) => f.sig.0.output,
ty_closure(ref f) => f.sig.0.output,
ref s => {
panic!("ty_fn_ret() called on non-fn type: {}", s)
}
}
}
pub fn is_fn_ty(fty: Ty) -> bool {
match fty.sty {
ty_bare_fn(..) => true,
ty_closure(_) => true,
_ => false
}
}
pub fn ty_region(tcx: &ctxt,
span: Span,
ty: Ty) -> Region {
match ty.sty {
ty_rptr(r, _) => *r,
ref s => {
tcx.sess.span_bug(
span,
format!("ty_region() invoked on an inappropriate ty: {}",
s)[]);
}
}
}
pub fn free_region_from_def(free_id: ast::NodeId, def: &RegionParameterDef)
-> ty::Region
{
ty::ReFree(ty::FreeRegion { scope: region::CodeExtent::from_node_id(free_id),
bound_region: ty::BrNamed(def.def_id,
def.name) })
}
// Returns the type of a pattern as a monotype. Like @expr_ty, this function
// doesn't provide type parameter substitutions.
pub fn pat_ty<'tcx>(cx: &ctxt<'tcx>, pat: &ast::Pat) -> Ty<'tcx> {
return node_id_to_type(cx, 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(&int) -> int"
// instead of "fn(ty) -> T with T = int".
pub fn expr_ty<'tcx>(cx: &ctxt<'tcx>, expr: &ast::Expr) -> Ty<'tcx> {
return node_id_to_type(cx, expr.id);
}
pub fn expr_ty_opt<'tcx>(cx: &ctxt<'tcx>, expr: &ast::Expr) -> Option<Ty<'tcx>> {
return node_id_to_type_opt(cx, 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
/// task at hand! -nmatsakis
pub fn expr_ty_adjusted<'tcx>(cx: &ctxt<'tcx>, expr: &ast::Expr) -> Ty<'tcx> {
adjust_ty(cx, expr.span, expr.id, expr_ty(cx, expr),
cx.adjustments.borrow().get(&expr.id),
|method_call| cx.method_map.borrow().get(&method_call).map(|method| method.ty))
}
pub fn expr_span(cx: &ctxt, id: NodeId) -> Span {
match cx.map.find(id) {
Some(ast_map::NodeExpr(e)) => {
e.span
}
Some(f) => {
cx.sess.bug(format!("Node id {} is not an expr: {}",
id,
f)[]);
}
None => {
cx.sess.bug(format!("Node id {} is not present \
in the node map", id)[]);
}
}
}
pub fn local_var_name_str(cx: &ctxt, id: NodeId) -> InternedString {
match cx.map.find(id) {
Some(ast_map::NodeLocal(pat)) => {
match pat.node {
ast::PatIdent(_, ref path1, _) => {
token::get_ident(path1.node)
}
_ => {
cx.sess.bug(
format!("Variable id {} maps to {}, not local",
id,
pat)[]);
}
}
}
r => {
cx.sess.bug(format!("Variable id {} maps to {}, not local",
id,
r)[]);
}
}
}
/// See `expr_ty_adjusted`
pub fn adjust_ty<'tcx, F>(cx: &ctxt<'tcx>,
span: Span,
expr_id: ast::NodeId,
unadjusted_ty: Ty<'tcx>,
adjustment: Option<&AutoAdjustment<'tcx>>,
mut method_type: F)
-> Ty<'tcx> where
F: FnMut(MethodCall) -> Option<Ty<'tcx>>,
{
if let ty_err = unadjusted_ty.sty {
return unadjusted_ty;
}
return match adjustment {
Some(adjustment) => {
match *adjustment {
AdjustAddEnv(_, store) => {
match unadjusted_ty.sty {
ty::ty_bare_fn(Some(_), ref b) => {
let bounds = ty::ExistentialBounds {
region_bound: ReStatic,
builtin_bounds: all_builtin_bounds(),
projection_bounds: vec!(),
};
ty::mk_closure(
cx,
ty::ClosureTy {unsafety: b.unsafety,
onceness: ast::Many,
store: store,
bounds: bounds,
sig: b.sig.clone(),
abi: b.abi})
}
ref b => {
cx.sess.bug(
format!("add_env adjustment on non-fn-item: \
{}",
b).as_slice());
}
}
}
AdjustReifyFnPointer(_) => {
match unadjusted_ty.sty {
ty::ty_bare_fn(Some(_), b) => {
ty::mk_bare_fn(cx, None, b)
}
ref b => {
cx.sess.bug(
format!("AdjustReifyFnPointer adjustment on non-fn-item: \
{}",
b)[]);
}
}
}
AdjustDerefRef(ref adj) => {
let mut adjusted_ty = unadjusted_ty;
if !ty::type_is_error(adjusted_ty) {
for i in range(0, adj.autoderefs) {
let method_call = MethodCall::autoderef(expr_id, i);
match method_type(method_call) {
Some(method_ty) => {
if let ty::FnConverging(result_type) = ty_fn_ret(method_ty) {
adjusted_ty = result_type;
}
}
None => {}
}
match deref(adjusted_ty, true) {
Some(mt) => { adjusted_ty = mt.ty; }
None => {
cx.sess.span_bug(
span,
format!("the {}th autoderef failed: \
{}",
i,
ty_to_string(cx, adjusted_ty))
[]);
}
}
}
}
adjust_ty_for_autoref(cx, span, adjusted_ty, adj.autoref.as_ref())
}
}
}
None => unadjusted_ty
};
}
pub fn adjust_ty_for_autoref<'tcx>(cx: &ctxt<'tcx>,
span: Span,
ty: Ty<'tcx>,
autoref: Option<&AutoRef<'tcx>>)
-> Ty<'tcx>
{
match autoref {
None => ty,
Some(&AutoPtr(r, m, ref a)) => {
let adjusted_ty = match a {
&Some(box ref a) => adjust_ty_for_autoref(cx, span, ty, Some(a)),
&None => ty
};
mk_rptr(cx, cx.mk_region(r), mt {
ty: adjusted_ty,
mutbl: m
})
}
Some(&AutoUnsafe(m, ref a)) => {
let adjusted_ty = match a {
&Some(box ref a) => adjust_ty_for_autoref(cx, span, ty, Some(a)),
&None => ty
};
mk_ptr(cx, mt {ty: adjusted_ty, mutbl: m})
}
Some(&AutoUnsize(ref k)) => unsize_ty(cx, ty, k, span),
Some(&AutoUnsizeUniq(ref k)) => ty::mk_uniq(cx, unsize_ty(cx, ty, k, span)),
}
}
// Take a sized type and a sizing adjustment and produce an unsized version of
// the type.
pub fn unsize_ty<'tcx>(cx: &ctxt<'tcx>,
ty: Ty<'tcx>,
kind: &UnsizeKind<'tcx>,
span: Span)
-> Ty<'tcx> {
match kind {
&UnsizeLength(len) => match ty.sty {
ty_vec(ty, Some(n)) => {
assert!(len == n);
mk_vec(cx, ty, None)
}
_ => cx.sess.span_bug(span,
format!("UnsizeLength with bad sty: {}",
ty_to_string(cx, ty))[])
},
&UnsizeStruct(box ref k, tp_index) => match ty.sty {
ty_struct(did, substs) => {
let ty_substs = substs.types.get_slice(subst::TypeSpace);
let new_ty = unsize_ty(cx, ty_substs[tp_index], k, span);
let mut unsized_substs = substs.clone();
unsized_substs.types.get_mut_slice(subst::TypeSpace)[tp_index] = new_ty;
mk_struct(cx, did, cx.mk_substs(unsized_substs))
}
_ => cx.sess.span_bug(span,
format!("UnsizeStruct with bad sty: {}",
ty_to_string(cx, ty))[])
},
&UnsizeVtable(TyTrait { ref principal, ref bounds }, _) => {
mk_trait(cx, principal.clone(), bounds.clone())
}
}
}
pub fn resolve_expr(tcx: &ctxt, expr: &ast::Expr) -> def::Def {
match tcx.def_map.borrow().get(&expr.id) {
Some(&def) => def,
None => {
tcx.sess.span_bug(expr.span, format!(
"no def-map entry for expr {}", expr.id)[]);
}
}
}
pub fn expr_is_lval(tcx: &ctxt, e: &ast::Expr) -> bool {
match expr_kind(tcx, e) {
LvalueExpr => true,
RvalueDpsExpr | RvalueDatumExpr | RvalueStmtExpr => false
}
}
/// We categorize expressions into three kinds. The distinction between
/// lvalue/rvalue is fundamental to the language. The distinction between the
/// two kinds of rvalues is an artifact of trans which reflects how we will
/// generate code for that kind of expression. See trans/expr.rs for more
/// information.
#[deriving(Copy)]
pub enum ExprKind {
LvalueExpr,
RvalueDpsExpr,
RvalueDatumExpr,
RvalueStmtExpr
}
pub fn expr_kind(tcx: &ctxt, expr: &ast::Expr) -> ExprKind {
if tcx.method_map.borrow().contains_key(&MethodCall::expr(expr.id)) {
// Overloaded operations are generally calls, and hence they are
// generated via DPS, but there are a few exceptions:
return match expr.node {
// `a += b` has a unit result.
ast::ExprAssignOp(..) => RvalueStmtExpr,
// the deref method invoked for `*a` always yields an `&T`
ast::ExprUnary(ast::UnDeref, _) => LvalueExpr,
// the index method invoked for `a[i]` always yields an `&T`
ast::ExprIndex(..) => LvalueExpr,
// `for` loops are statements
ast::ExprForLoop(..) => RvalueStmtExpr,
// in the general case, result could be any type, use DPS
_ => RvalueDpsExpr
};
}
match expr.node {
ast::ExprPath(..) => {
match resolve_expr(tcx, expr) {
def::DefVariant(tid, vid, _) => {
let variant_info = enum_variant_with_id(tcx, tid, vid);
if variant_info.args.len() > 0u {
// N-ary variant.
RvalueDatumExpr
} else {
// Nullary variant.
RvalueDpsExpr
}
}
def::DefStruct(_) => {
match tcx.node_types.borrow().get(&expr.id) {
Some(ty) => match ty.sty {
ty_bare_fn(..) => RvalueDatumExpr,
_ => RvalueDpsExpr
},
// See ExprCast below for why types might be missing.
None => RvalueDatumExpr
}
}
// Special case: A unit like struct's constructor must be called without () at the
// end (like `UnitStruct`) which means this is an ExprPath to a DefFn. But in case
// of unit structs this is should not be interpreted as function pointer but as
// call to the constructor.
def::DefFn(_, true) => RvalueDpsExpr,
// Fn pointers are just scalar values.
def::DefFn(..) | def::DefStaticMethod(..) | def::DefMethod(..) => RvalueDatumExpr,
// Note: there is actually a good case to be made that
// DefArg's, particularly those of immediate type, ought to
// considered rvalues.
def::DefStatic(..) |
def::DefUpvar(..) |
def::DefLocal(..) => LvalueExpr,
def::DefConst(..) => RvalueDatumExpr,
def => {
tcx.sess.span_bug(
expr.span,
format!("uncategorized def for expr {}: {}",
expr.id,
def)[]);
}
}
}
ast::ExprUnary(ast::UnDeref, _) |
ast::ExprField(..) |
ast::ExprTupField(..) |
ast::ExprIndex(..) => {
LvalueExpr
}
ast::ExprCall(..) |
ast::ExprMethodCall(..) |
ast::ExprStruct(..) |
ast::ExprRange(..) |
ast::ExprTup(..) |
ast::ExprIf(..) |
ast::ExprMatch(..) |
ast::ExprClosure(..) |
ast::ExprBlock(..) |
ast::ExprRepeat(..) |
ast::ExprVec(..) => {
RvalueDpsExpr
}
ast::ExprIfLet(..) => {
tcx.sess.span_bug(expr.span, "non-desugared ExprIfLet");
}
ast::ExprWhileLet(..) => {
tcx.sess.span_bug(expr.span, "non-desugared ExprWhileLet");
}
ast::ExprLit(ref lit) if lit_is_str(&**lit) => {
RvalueDpsExpr
}
ast::ExprCast(..) => {
match tcx.node_types.borrow().get(&expr.id) {
Some(&ty) => {
if type_is_trait(ty) {
RvalueDpsExpr
} else {
RvalueDatumExpr
}
}
None => {
// Technically, it should not happen that the expr is not
// present within the table. However, it DOES happen
// during type check, because the final types from the
// expressions are not yet recorded in the tcx. At that
// time, though, we are only interested in knowing lvalue
// vs rvalue. It would be better to base this decision on
// the AST type in cast node---but (at the time of this
// writing) it's not easy to distinguish casts to traits
// from other casts based on the AST. This should be
// easier in the future, when casts to traits
// would like @Foo, Box<Foo>, or &Foo.
RvalueDatumExpr
}
}
}
ast::ExprBreak(..) |
ast::ExprAgain(..) |
ast::ExprRet(..) |
ast::ExprWhile(..) |
ast::ExprLoop(..) |
ast::ExprAssign(..) |
ast::ExprInlineAsm(..) |
ast::ExprAssignOp(..) |
ast::ExprForLoop(..) => {
RvalueStmtExpr
}
ast::ExprLit(_) | // Note: LitStr is carved out above
ast::ExprUnary(..) |
ast::ExprBox(None, _) |
ast::ExprAddrOf(..) |
ast::ExprBinary(..) => {
RvalueDatumExpr
}
ast::ExprBox(Some(ref place), _) => {
// Special case `Box<T>` for now:
let definition = match tcx.def_map.borrow().get(&place.id) {
Some(&def) => def,
None => panic!("no def for place"),
};
let def_id = definition.def_id();
if tcx.lang_items.exchange_heap() == Some(def_id) {
RvalueDatumExpr
} else {
RvalueDpsExpr
}
}
ast::ExprParen(ref e) => expr_kind(tcx, &**e),
ast::ExprMac(..) => {
tcx.sess.span_bug(
expr.span,
"macro expression remains after expansion");
}
}
}
pub fn stmt_node_id(s: &ast::Stmt) -> ast::NodeId {
match s.node {
ast::StmtDecl(_, id) | StmtExpr(_, id) | StmtSemi(_, id) => {
return id;
}
ast::StmtMac(..) => panic!("unexpanded macro in trans")
}
}
pub fn field_idx_strict(tcx: &ctxt, name: ast::Name, fields: &[field])
-> uint {
let mut i = 0u;
for f in fields.iter() { if f.name == name { return i; } i += 1u; }
tcx.sess.bug(format!(
"no field named `{}` found in the list of fields `{}`",
token::get_name(name),
fields.iter()
.map(|f| token::get_name(f.name).get().to_string())
.collect::<Vec<String>>())[]);
}
pub fn impl_or_trait_item_idx(id: ast::Name, trait_items: &[ImplOrTraitItem])
-> Option<uint> {
trait_items.iter().position(|m| m.name() == id)
}
pub fn ty_sort_string<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> String {
match ty.sty {
ty_bool | ty_char | ty_int(_) |
ty_uint(_) | ty_float(_) | ty_str => {
::util::ppaux::ty_to_string(cx, ty)
}
ty_tup(ref tys) if tys.is_empty() => ::util::ppaux::ty_to_string(cx, ty),
ty_enum(id, _) => format!("enum {}", item_path_str(cx, id)),
ty_uniq(_) => "box".to_string(),
ty_vec(_, Some(n)) => format!("array of {} elements", n),
ty_vec(_, None) => "slice".to_string(),
ty_ptr(_) => "*-ptr".to_string(),
ty_rptr(_, _) => "&-ptr".to_string(),
ty_bare_fn(Some(_), _) => format!("fn item"),
ty_bare_fn(None, _) => "fn pointer".to_string(),
ty_closure(_) => "fn".to_string(),
ty_trait(ref inner) => {
format!("trait {}", item_path_str(cx, inner.principal_def_id()))
}
ty_struct(id, _) => {
format!("struct {}", item_path_str(cx, id))
}
ty_unboxed_closure(..) => "closure".to_string(),
ty_tup(_) => "tuple".to_string(),
ty_infer(TyVar(_)) => "inferred type".to_string(),
ty_infer(IntVar(_)) => "integral variable".to_string(),
ty_infer(FloatVar(_)) => "floating-point variable".to_string(),
ty_infer(FreshTy(_)) => "skolemized type".to_string(),
ty_infer(FreshIntTy(_)) => "skolemized integral type".to_string(),
ty_projection(_) => "associated type".to_string(),
ty_param(ref p) => {
if p.space == subst::SelfSpace {
"Self".to_string()
} else {
"type parameter".to_string()
}
}
ty_err => "type error".to_string(),
ty_open(_) => "opened DST".to_string(),
}
}
impl<'tcx> Repr<'tcx> for ty::type_err<'tcx> {
fn repr(&self, tcx: &ty::ctxt<'tcx>) -> String {
ty::type_err_to_str(tcx, self)
}
}
/// Explains the source of a type err in a short, human readable way. This is meant to be placed
/// in parentheses after some larger message. You should also invoke `note_and_explain_type_err()`
/// afterwards to present additional details, particularly when it comes to lifetime-related
/// errors.
pub fn type_err_to_str<'tcx>(cx: &ctxt<'tcx>, err: &type_err<'tcx>) -> String {
fn tstore_to_closure(s: &TraitStore) -> String {
match s {
&UniqTraitStore => "proc".to_string(),
&RegionTraitStore(..) => "closure".to_string()
}
}
match *err {
terr_cyclic_ty => "cyclic type of infinite size".to_string(),
terr_mismatch => "types differ".to_string(),
terr_unsafety_mismatch(values) => {
format!("expected {} fn, found {} fn",
values.expected.to_string(),
values.found.to_string())
}
terr_abi_mismatch(values) => {
format!("expected {} fn, found {} fn",
values.expected.to_string(),
values.found.to_string())
}
terr_onceness_mismatch(values) => {
format!("expected {} fn, found {} fn",
values.expected.to_string(),
values.found.to_string())
}
terr_sigil_mismatch(values) => {
format!("expected {}, found {}",
tstore_to_closure(&values.expected),
tstore_to_closure(&values.found))
}
terr_mutability => "values differ in mutability".to_string(),
terr_box_mutability => {
"boxed values differ in mutability".to_string()
}
terr_vec_mutability => "vectors differ in mutability".to_string(),
terr_ptr_mutability => "pointers differ in mutability".to_string(),
terr_ref_mutability => "references differ in mutability".to_string(),
terr_ty_param_size(values) => {
format!("expected a type with {} type params, \
found one with {} type params",
values.expected,
values.found)
}
terr_fixed_array_size(values) => {
format!("expected an array with a fixed size of {} elements, \
found one with {} elements",
values.expected,
values.found)
}
terr_tuple_size(values) => {
format!("expected a tuple with {} elements, \
found one with {} elements",
values.expected,
values.found)
}
terr_arg_count => {
"incorrect number of function parameters".to_string()
}
terr_regions_does_not_outlive(..) => {
"lifetime mismatch".to_string()
}
terr_regions_not_same(..) => {
"lifetimes are not the same".to_string()
}
terr_regions_no_overlap(..) => {
"lifetimes do not intersect".to_string()
}
terr_regions_insufficiently_polymorphic(br, _) => {
format!("expected bound lifetime parameter {}, \
found concrete lifetime",
bound_region_ptr_to_string(cx, br))
}
terr_regions_overly_polymorphic(br, _) => {
format!("expected concrete lifetime, \
found bound lifetime parameter {}",
bound_region_ptr_to_string(cx, br))
}
terr_trait_stores_differ(_, ref values) => {
format!("trait storage differs: expected `{}`, found `{}`",
trait_store_to_string(cx, (*values).expected),
trait_store_to_string(cx, (*values).found))
}
terr_sorts(values) => {
// A naive approach to making sure that we're not reporting silly errors such as:
// (expected closure, found closure).
let expected_str = ty_sort_string(cx, values.expected);
let found_str = ty_sort_string(cx, values.found);
if expected_str == found_str {
format!("expected {}, found a different {}", expected_str, found_str)
} else {
format!("expected {}, found {}", expected_str, found_str)
}
}
terr_traits(values) => {
format!("expected trait `{}`, found trait `{}`",
item_path_str(cx, values.expected),
item_path_str(cx, values.found))
}
terr_builtin_bounds(values) => {
if values.expected.is_empty() {
format!("expected no bounds, found `{}`",
values.found.user_string(cx))
} else if values.found.is_empty() {
format!("expected bounds `{}`, found no bounds",
values.expected.user_string(cx))
} else {
format!("expected bounds `{}`, found bounds `{}`",
values.expected.user_string(cx),
values.found.user_string(cx))
}
}
terr_integer_as_char => {
"expected an integral type, found `char`".to_string()
}
terr_int_mismatch(ref values) => {
format!("expected `{}`, found `{}`",
values.expected.to_string(),
values.found.to_string())
}
terr_float_mismatch(ref values) => {
format!("expected `{}`, found `{}`",
values.expected.to_string(),
values.found.to_string())
}
terr_variadic_mismatch(ref values) => {
format!("expected {} fn, found {} function",
if values.expected { "variadic" } else { "non-variadic" },
if values.found { "variadic" } else { "non-variadic" })
}
terr_convergence_mismatch(ref values) => {
format!("expected {} fn, found {} function",
if values.expected { "converging" } else { "diverging" },
if values.found { "converging" } else { "diverging" })
}
terr_projection_name_mismatched(ref values) => {
format!("expected {}, found {}",
token::get_name(values.expected),
token::get_name(values.found))
}
terr_projection_bounds_length(ref values) => {
format!("expected {} associated type bindings, found {}",
values.expected,
values.found)
}
}
}
pub fn note_and_explain_type_err(cx: &ctxt, err: &type_err) {
match *err {
terr_regions_does_not_outlive(subregion, superregion) => {
note_and_explain_region(cx, "", subregion, "...");
note_and_explain_region(cx, "...does not necessarily outlive ",
superregion, "");
}
terr_regions_not_same(region1, region2) => {
note_and_explain_region(cx, "", region1, "...");
note_and_explain_region(cx, "...is not the same lifetime as ",
region2, "");
}
terr_regions_no_overlap(region1, region2) => {
note_and_explain_region(cx, "", region1, "...");
note_and_explain_region(cx, "...does not overlap ",
region2, "");
}
terr_regions_insufficiently_polymorphic(_, conc_region) => {
note_and_explain_region(cx,
"concrete lifetime that was found is ",
conc_region, "");
}
terr_regions_overly_polymorphic(_, ty::ReInfer(ty::ReVar(_))) => {
// don't bother to print out the message below for
// inference variables, it's not very illuminating.
}
terr_regions_overly_polymorphic(_, conc_region) => {
note_and_explain_region(cx,
"expected concrete lifetime is ",
conc_region, "");
}
_ => {}
}
}
pub fn provided_source(cx: &ctxt, id: ast::DefId) -> Option<ast::DefId> {
cx.provided_method_sources.borrow().get(&id).map(|x| *x)
}
pub fn provided_trait_methods<'tcx>(cx: &ctxt<'tcx>, id: ast::DefId)
-> Vec<Rc<Method<'tcx>>> {
if is_local(id) {
match cx.map.find(id.node) {
Some(ast_map::NodeItem(item)) => {
match item.node {
ItemTrait(_, _, _, ref ms) => {
let (_, p) =
ast_util::split_trait_methods(ms[]);
p.iter()
.map(|m| {
match impl_or_trait_item(
cx,
ast_util::local_def(m.id)) {
MethodTraitItem(m) => m,
TypeTraitItem(_) => {
cx.sess.bug("provided_trait_methods(): \
split_trait_methods() put \
associated types in the \
provided method bucket?!")
}
}
}).collect()
}
_ => {
cx.sess.bug(format!("provided_trait_methods: `{}` is \
not a trait",
id)[])
}
}
}
_ => {
cx.sess.bug(format!("provided_trait_methods: `{}` is not a \
trait",
id)[])
}
}
} else {
csearch::get_provided_trait_methods(cx, id)
}
}
/// Helper for looking things up in the various maps that are populated during typeck::collect
/// (e.g., `cx.impl_or_trait_items`, `cx.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<V, F>(descr: &str,
def_id: ast::DefId,
map: &mut DefIdMap<V>,
load_external: F) -> V where
V: Clone,
F: FnOnce() -> V,
{
match map.get(&def_id).cloned() {
Some(v) => { return v; }
None => { }
}
if def_id.krate == ast::LOCAL_CRATE {
panic!("No def'n found for {} in tcx.{}", def_id, descr);
}
let v = load_external();
map.insert(def_id, v.clone());
v
}
pub fn trait_item<'tcx>(cx: &ctxt<'tcx>, trait_did: ast::DefId, idx: uint)
-> ImplOrTraitItem<'tcx> {
let method_def_id = (*ty::trait_item_def_ids(cx, trait_did))[idx].def_id();
impl_or_trait_item(cx, method_def_id)
}
pub fn trait_items<'tcx>(cx: &ctxt<'tcx>, trait_did: ast::DefId)
-> Rc<Vec<ImplOrTraitItem<'tcx>>> {
let mut trait_items = cx.trait_items_cache.borrow_mut();
match trait_items.get(&trait_did).cloned() {
Some(trait_items) => trait_items,
None => {
let def_ids = ty::trait_item_def_ids(cx, trait_did);
let items: Rc<Vec<ImplOrTraitItem>> =
Rc::new(def_ids.iter()
.map(|d| impl_or_trait_item(cx, d.def_id()))
.collect());
trait_items.insert(trait_did, items.clone());
items
}
}
}
pub fn impl_or_trait_item<'tcx>(cx: &ctxt<'tcx>, id: ast::DefId)
-> ImplOrTraitItem<'tcx> {
lookup_locally_or_in_crate_store("impl_or_trait_items",
id,
&mut *cx.impl_or_trait_items
.borrow_mut(),
|| {
csearch::get_impl_or_trait_item(cx, id)
})
}
/// Returns true if the given ID refers to an associated type and false if it
/// refers to anything else.
pub fn is_associated_type(cx: &ctxt, id: ast::DefId) -> bool {
memoized(&cx.associated_types, id, |id: ast::DefId| {
if id.krate == ast::LOCAL_CRATE {
match cx.impl_or_trait_items.borrow().get(&id) {
Some(ref item) => {
match **item {
TypeTraitItem(_) => true,
MethodTraitItem(_) => false,
}
}
None => false,
}
} else {
csearch::is_associated_type(&cx.sess.cstore, id)
}
})
}
/// Returns the parameter index that the given associated type corresponds to.
pub fn associated_type_parameter_index(cx: &ctxt,
trait_def: &TraitDef,
associated_type_id: ast::DefId)
-> uint {
for type_parameter_def in trait_def.generics.types.iter() {
if type_parameter_def.def_id == associated_type_id {
return type_parameter_def.index as uint
}
}
cx.sess.bug("couldn't find associated type parameter index")
}
#[deriving(Copy, PartialEq, Eq)]
pub struct AssociatedTypeInfo {
pub def_id: ast::DefId,
pub index: uint,
pub name: ast::Name,
}
impl PartialOrd for AssociatedTypeInfo {
fn partial_cmp(&self, other: &AssociatedTypeInfo) -> Option<Ordering> {
Some(self.index.cmp(&other.index))
}
}
impl Ord for AssociatedTypeInfo {
fn cmp(&self, other: &AssociatedTypeInfo) -> Ordering {
self.index.cmp(&other.index)
}
}
pub fn trait_item_def_ids(cx: &ctxt, id: ast::DefId)
-> Rc<Vec<ImplOrTraitItemId>> {
lookup_locally_or_in_crate_store("trait_item_def_ids",
id,
&mut *cx.trait_item_def_ids.borrow_mut(),
|| {
Rc::new(csearch::get_trait_item_def_ids(&cx.sess.cstore, id))
})
}
pub fn impl_trait_ref<'tcx>(cx: &ctxt<'tcx>, id: ast::DefId)
-> Option<Rc<TraitRef<'tcx>>> {
memoized(&cx.impl_trait_cache, id, |id: ast::DefId| {
if id.krate == ast::LOCAL_CRATE {
debug!("(impl_trait_ref) searching for trait impl {}", id);
match cx.map.find(id.node) {
Some(ast_map::NodeItem(item)) => {
match item.node {
ast::ItemImpl(_, _, ref opt_trait, _, _) => {
match opt_trait {
&Some(ref t) => {
let trait_ref = ty::node_id_to_trait_ref(cx, t.ref_id);
Some(trait_ref)
}
&None => None
}
}
_ => None
}
}
_ => None
}
} else {
csearch::get_impl_trait(cx, id)
}
})
}
pub fn trait_ref_to_def_id(tcx: &ctxt, tr: &ast::TraitRef) -> ast::DefId {
let def = *tcx.def_map.borrow()
.get(&tr.ref_id)
.expect("no def-map entry for trait");
def.def_id()
}
pub fn try_add_builtin_trait(
tcx: &ctxt,
trait_def_id: ast::DefId,
builtin_bounds: &mut EnumSet<BuiltinBound>)
-> bool
{
//! Checks whether `trait_ref` refers to one of the builtin
//! traits, like `Send`, and adds the corresponding
//! bound to the set `builtin_bounds` if so. Returns true if `trait_ref`
//! is a builtin trait.
match tcx.lang_items.to_builtin_kind(trait_def_id) {
Some(bound) => { builtin_bounds.insert(bound); true }
None => false
}
}
pub fn ty_to_def_id(ty: Ty) -> Option<ast::DefId> {
match ty.sty {
ty_trait(ref tt) =>
Some(tt.principal_def_id()),
ty_struct(id, _) |
ty_enum(id, _) |
ty_unboxed_closure(id, _, _) =>
Some(id),
_ =>
None
}
}
// Enum information
#[deriving(Clone)]
pub struct VariantInfo<'tcx> {
pub args: Vec<Ty<'tcx>>,
pub arg_names: Option<Vec<ast::Ident>>,
pub ctor_ty: Option<Ty<'tcx>>,
pub name: ast::Name,
pub id: ast::DefId,
pub disr_val: Disr,
pub vis: Visibility
}
impl<'tcx> VariantInfo<'tcx> {
/// Creates a new VariantInfo from the corresponding ast representation.
///
/// Does not do any caching of the value in the type context.
pub fn from_ast_variant(cx: &ctxt<'tcx>,
ast_variant: &ast::Variant,
discriminant: Disr) -> VariantInfo<'tcx> {
let ctor_ty = node_id_to_type(cx, ast_variant.node.id);
match ast_variant.node.kind {
ast::TupleVariantKind(ref args) => {
let arg_tys = if args.len() > 0 {
ty_fn_args(ctor_ty).iter().map(|a| *a).collect()
} else {
Vec::new()
};
return VariantInfo {
args: arg_tys,
arg_names: None,
ctor_ty: Some(ctor_ty),
name: ast_variant.node.name.name,
id: ast_util::local_def(ast_variant.node.id),
disr_val: discriminant,
vis: ast_variant.node.vis
};
},
ast::StructVariantKind(ref struct_def) => {
let fields: &[StructField] = struct_def.fields[];
assert!(fields.len() > 0);
let arg_tys = struct_def.fields.iter()
.map(|field| node_id_to_type(cx, field.node.id)).collect();
let arg_names = fields.iter().map(|field| {
match field.node.kind {
NamedField(ident, _) => ident,
UnnamedField(..) => cx.sess.bug(
"enum_variants: all fields in struct must have a name")
}
}).collect();
return VariantInfo {
args: arg_tys,
arg_names: Some(arg_names),
ctor_ty: None,
name: ast_variant.node.name.name,
id: ast_util::local_def(ast_variant.node.id),
disr_val: discriminant,
vis: ast_variant.node.vis
};
}
}
}
}
pub fn substd_enum_variants<'tcx>(cx: &ctxt<'tcx>,
id: ast::DefId,
substs: &Substs<'tcx>)
-> Vec<Rc<VariantInfo<'tcx>>> {
enum_variants(cx, id).iter().map(|variant_info| {
let substd_args = variant_info.args.iter()
.map(|aty| aty.subst(cx, substs)).collect::<Vec<_>>();
let substd_ctor_ty = variant_info.ctor_ty.subst(cx, substs);
Rc::new(VariantInfo {
args: substd_args,
ctor_ty: substd_ctor_ty,
..(**variant_info).clone()
})
}).collect()
}
pub fn item_path_str(cx: &ctxt, id: ast::DefId) -> String {
with_path(cx, id, |path| ast_map::path_to_string(path)).to_string()
}
#[deriving(Copy)]
pub enum DtorKind {
NoDtor,
TraitDtor(DefId, bool)
}
impl DtorKind {
pub fn is_present(&self) -> bool {
match *self {
TraitDtor(..) => true,
_ => false
}
}
pub fn has_drop_flag(&self) -> bool {
match self {
&NoDtor => false,
&TraitDtor(_, flag) => flag
}
}
}
/* If struct_id names a struct with a dtor, return Some(the dtor's id).
Otherwise return none. */
pub fn ty_dtor(cx: &ctxt, struct_id: DefId) -> DtorKind {
match cx.destructor_for_type.borrow().get(&struct_id) {
Some(&method_def_id) => {
let flag = !has_attr(cx, struct_id, "unsafe_no_drop_flag");
TraitDtor(method_def_id, flag)
}
None => NoDtor,
}
}
pub fn has_dtor(cx: &ctxt, struct_id: DefId) -> bool {
cx.destructor_for_type.borrow().contains_key(&struct_id)
}
pub fn with_path<T, F>(cx: &ctxt, id: ast::DefId, f: F) -> T where
F: FnOnce(ast_map::PathElems) -> T,
{
if id.krate == ast::LOCAL_CRATE {
cx.map.with_path(id.node, f)
} else {
f(ast_map::Values(csearch::get_item_path(cx, id).iter()).chain(None))
}
}
pub fn enum_is_univariant(cx: &ctxt, id: ast::DefId) -> bool {
enum_variants(cx, id).len() == 1
}
pub fn type_is_empty(cx: &ctxt, ty: Ty) -> bool {
match ty.sty {
ty_enum(did, _) => (*enum_variants(cx, did)).is_empty(),
_ => false
}
}
pub fn enum_variants<'tcx>(cx: &ctxt<'tcx>, id: ast::DefId)
-> Rc<Vec<Rc<VariantInfo<'tcx>>>> {
memoized(&cx.enum_var_cache, id, |id: ast::DefId| {
if ast::LOCAL_CRATE != id.krate {
Rc::new(csearch::get_enum_variants(cx, id))
} else {
/*
Although both this code and check_enum_variants in typeck/check
call eval_const_expr, it should never get called twice for the same
expr, since check_enum_variants also updates the enum_var_cache
*/
match cx.map.get(id.node) {
ast_map::NodeItem(ref item) => {
match item.node {
ast::ItemEnum(ref enum_definition, _) => {
let mut last_discriminant: Option<Disr> = None;
Rc::new(enum_definition.variants.iter().map(|variant| {
let mut discriminant = match last_discriminant {
Some(val) => val + 1,
None => INITIAL_DISCRIMINANT_VALUE
};
match variant.node.disr_expr {
Some(ref e) =>
match const_eval::eval_const_expr_partial(cx, &**e) {
Ok(const_eval::const_int(val)) => {
discriminant = val as Disr
}
Ok(const_eval::const_uint(val)) => {
discriminant = val as Disr
}
Ok(_) => {
cx.sess
.span_err(e.span,
"expected signed integer constant");
}
Err(ref err) => {
cx.sess
.span_err(e.span,
format!("expected constant: {}",
*err)[]);
}
},
None => {}
};
last_discriminant = Some(discriminant);
Rc::new(VariantInfo::from_ast_variant(cx, &**variant,
discriminant))
}).collect())
}
_ => {
cx.sess.bug("enum_variants: id not bound to an enum")
}
}
}
_ => cx.sess.bug("enum_variants: id not bound to an enum")
}
}
})
}
// Returns information about the enum variant with the given ID:
pub fn enum_variant_with_id<'tcx>(cx: &ctxt<'tcx>,
enum_id: ast::DefId,
variant_id: ast::DefId)
-> Rc<VariantInfo<'tcx>> {
enum_variants(cx, enum_id).iter()
.find(|variant| variant.id == variant_id)
.expect("enum_variant_with_id(): no variant exists with that ID")
.clone()
}
// 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<'tcx>(cx: &ctxt<'tcx>,
did: ast::DefId)
-> TypeScheme<'tcx> {
lookup_locally_or_in_crate_store(
"tcache", did, &mut *cx.tcache.borrow_mut(),
|| csearch::get_type(cx, did))
}
/// Given the did of a trait, returns its canonical trait ref.
pub fn lookup_trait_def<'tcx>(cx: &ctxt<'tcx>, did: ast::DefId)
-> Rc<ty::TraitDef<'tcx>> {
memoized(&cx.trait_defs, did, |did: DefId| {
assert!(did.krate != ast::LOCAL_CRATE);
Rc::new(csearch::get_trait_def(cx, did))
})
}
/// Given a reference to a trait, returns the "superbounds" declared
/// on the trait, with appropriate substitutions applied. Basically,
/// this applies a filter to the where clauses on the trait, returning
/// those that have the form:
///
/// Self : SuperTrait<...>
/// Self : 'region
pub fn predicates_for_trait_ref<'tcx>(tcx: &ctxt<'tcx>,
trait_ref: &PolyTraitRef<'tcx>)
-> Vec<ty::Predicate<'tcx>>
{
let trait_def = lookup_trait_def(tcx, trait_ref.def_id());
debug!("bounds_for_trait_ref(trait_def={}, trait_ref={})",
trait_def.repr(tcx), trait_ref.repr(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).
// Carefully avoid the binder introduced by each trait-ref by
// substituting over the substs, not the trait-refs themselves,
// thus achieving the "collapse" described in the big comment
// above.
let trait_bounds: Vec<_> =
trait_def.bounds.trait_bounds
.iter()
.map(|poly_trait_ref| ty::Binder(poly_trait_ref.0.subst(tcx, trait_ref.substs())))
.collect();
let projection_bounds: Vec<_> =
trait_def.bounds.projection_bounds
.iter()
.map(|poly_proj| ty::Binder(poly_proj.0.subst(tcx, trait_ref.substs())))
.collect();
debug!("bounds_for_trait_ref: trait_bounds={} projection_bounds={}",
trait_bounds.repr(tcx),
projection_bounds.repr(tcx));
// The region bounds and builtin bounds do not currently introduce
// binders so we can just substitute in a straightforward way here.
let region_bounds =
trait_def.bounds.region_bounds.subst(tcx, trait_ref.substs());
let builtin_bounds =
trait_def.bounds.builtin_bounds.subst(tcx, trait_ref.substs());
let bounds = ty::ParamBounds {
trait_bounds: trait_bounds,
region_bounds: region_bounds,
builtin_bounds: builtin_bounds,
projection_bounds: projection_bounds,
};
predicates(tcx, trait_ref.self_ty(), &bounds)
}
pub fn predicates<'tcx>(
tcx: &ctxt<'tcx>,
param_ty: Ty<'tcx>,
bounds: &ParamBounds<'tcx>)
-> Vec<Predicate<'tcx>>
{
let mut vec = Vec::new();
for builtin_bound in bounds.builtin_bounds.iter() {
match traits::trait_ref_for_builtin_bound(tcx, builtin_bound, param_ty) {
Ok(trait_ref) => { vec.push(trait_ref.as_predicate()); }
Err(ErrorReported) => { }
}
}
for &region_bound in bounds.region_bounds.iter() {
// account for the binder being introduced below; no need to shift `param_ty`
// because, at present at least, it can only refer to early-bound regions
let region_bound = ty_fold::shift_region(region_bound, 1);
vec.push(ty::Binder(ty::OutlivesPredicate(param_ty, region_bound)).as_predicate());
}
for bound_trait_ref in bounds.trait_bounds.iter() {
vec.push(bound_trait_ref.as_predicate());
}
for projection in bounds.projection_bounds.iter() {
vec.push(projection.as_predicate());
}
vec
}
/// Iterate over attributes of a definition.
// (This should really be an iterator, but that would require csearch and
// decoder to use iterators instead of higher-order functions.)
pub fn each_attr<F>(tcx: &ctxt, did: DefId, mut f: F) -> bool where
F: FnMut(&ast::Attribute) -> bool,
{
if is_local(did) {
let item = tcx.map.expect_item(did.node);
item.attrs.iter().all(|attr| f(attr))
} else {
info!("getting foreign attrs");
let mut cont = true;
csearch::get_item_attrs(&tcx.sess.cstore, did, |attrs| {
if cont {
cont = attrs.iter().all(|attr| f(attr));
}
});
info!("done");
cont
}
}
/// Determine whether an item is annotated with an attribute
pub fn has_attr(tcx: &ctxt, did: DefId, attr: &str) -> bool {
let mut found = false;
each_attr(tcx, did, |item| {
if item.check_name(attr) {
found = true;
false
} else {
true
}
});
found
}
/// Determine whether an item is annotated with `#[repr(packed)]`
pub fn lookup_packed(tcx: &ctxt, did: DefId) -> bool {
lookup_repr_hints(tcx, did).contains(&attr::ReprPacked)
}
/// Determine whether an item is annotated with `#[simd]`
pub fn lookup_simd(tcx: &ctxt, did: DefId) -> bool {
has_attr(tcx, did, "simd")
}
/// Obtain the representation annotation for a struct definition.
pub fn lookup_repr_hints(tcx: &ctxt, did: DefId) -> Rc<Vec<attr::ReprAttr>> {
memoized(&tcx.repr_hint_cache, did, |did: DefId| {
Rc::new(if did.krate == LOCAL_CRATE {
let mut acc = Vec::new();
ty::each_attr(tcx, did, |meta| {
acc.extend(attr::find_repr_attrs(tcx.sess.diagnostic(),
meta).into_iter());
true
});
acc
} else {
csearch::get_repr_attrs(&tcx.sess.cstore, did)
})
})
}
// Look up a field ID, whether or not it's local
// Takes a list of type substs in case the struct is generic
pub fn lookup_field_type<'tcx>(tcx: &ctxt<'tcx>,
struct_id: DefId,
id: DefId,
substs: &Substs<'tcx>)
-> Ty<'tcx> {
let ty = if id.krate == ast::LOCAL_CRATE {
node_id_to_type(tcx, id.node)
} else {
let mut tcache = tcx.tcache.borrow_mut();
let pty = match tcache.entry(id) {
Occupied(entry) => entry.into_mut(),
Vacant(entry) => entry.set(csearch::get_field_type(tcx, struct_id, id)),
};
pty.ty
};
ty.subst(tcx, substs)
}
// Look up the list of field names and IDs for a given struct.
// Panics if the id is not bound to a struct.
pub fn lookup_struct_fields(cx: &ctxt, did: ast::DefId) -> Vec<field_ty> {
if did.krate == ast::LOCAL_CRATE {
let struct_fields = cx.struct_fields.borrow();
match struct_fields.get(&did) {
Some(fields) => (**fields).clone(),
_ => {
cx.sess.bug(
format!("ID not mapped to struct fields: {}",
cx.map.node_to_string(did.node))[]);
}
}
} else {
csearch::get_struct_fields(&cx.sess.cstore, did)
}
}
pub fn is_tuple_struct(cx: &ctxt, did: ast::DefId) -> bool {
let fields = lookup_struct_fields(cx, did);
!fields.is_empty() && fields.iter().all(|f| f.name == token::special_names::unnamed_field)
}
// Returns a list of fields corresponding to the struct's items. trans uses
// this. Takes a list of substs with which to instantiate field types.
pub fn struct_fields<'tcx>(cx: &ctxt<'tcx>, did: ast::DefId, substs: &Substs<'tcx>)
-> Vec<field<'tcx>> {
lookup_struct_fields(cx, did).iter().map(|f| {
field {
name: f.name,
mt: mt {
ty: lookup_field_type(cx, did, f.id, substs),
mutbl: MutImmutable
}
}
}).collect()
}
// Returns a list of fields corresponding to the tuple's items. trans uses
// this.
pub fn tup_fields<'tcx>(v: &[Ty<'tcx>]) -> Vec<field<'tcx>> {
v.iter().enumerate().map(|(i, &f)| {
field {
name: token::intern(i.to_string()[]),
mt: mt {
ty: f,
mutbl: MutImmutable
}
}
}).collect()
}
#[deriving(Copy, Clone)]
pub struct UnboxedClosureUpvar<'tcx> {
pub def: def::Def,
pub span: Span,
pub ty: Ty<'tcx>,
}
// Returns a list of `UnboxedClosureUpvar`s for each upvar.
pub fn unboxed_closure_upvars<'tcx>(typer: &mc::Typer<'tcx>,
closure_id: ast::DefId,
substs: &Substs<'tcx>)
-> Option<Vec<UnboxedClosureUpvar<'tcx>>>
{
// Presently an unboxed closure type cannot "escape" out of a
// function, so we will only encounter ones that originated in the
// local crate or were inlined into it along with some function.
// This may change if abstract return types of some sort are
// implemented.
assert!(closure_id.krate == ast::LOCAL_CRATE);
let tcx = typer.tcx();
let capture_mode = tcx.capture_modes.borrow()[closure_id.node].clone();
match tcx.freevars.borrow().get(&closure_id.node) {
None => Some(vec![]),
Some(ref freevars) => {
freevars.iter()
.map(|freevar| {
let freevar_def_id = freevar.def.def_id();
let freevar_ty = typer.node_ty(freevar_def_id.node);
let freevar_ty = freevar_ty.subst(tcx, substs);
match capture_mode {
ast::CaptureByValue => {
Some(UnboxedClosureUpvar { def: freevar.def,
span: freevar.span,
ty: freevar_ty })
}
ast::CaptureByRef => {
let upvar_id = ty::UpvarId {
var_id: freevar_def_id.node,
closure_expr_id: closure_id.node
};
// FIXME
let freevar_ref_ty = match typer.upvar_borrow(upvar_id) {
Some(borrow) => {
mk_rptr(tcx,
tcx.mk_region(borrow.region),
ty::mt {
ty: freevar_ty,
mutbl: borrow.kind.to_mutbl_lossy(),
})
}
None => {
// FIXME(#16640) we should really return None here;
// but that requires better inference integration,
// for now gin up something.
freevar_ty
}
};
Some(UnboxedClosureUpvar {
def: freevar.def,
span: freevar.span,
ty: freevar_ref_ty,
})
}
}
})
.collect()
}
}
}
pub fn is_binopable<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>, op: ast::BinOp) -> bool {
#![allow(non_upper_case_globals)]
static tycat_other: int = 0;
static tycat_bool: int = 1;
static tycat_char: int = 2;
static tycat_int: int = 3;
static tycat_float: int = 4;
static tycat_raw_ptr: int = 6;
static opcat_add: int = 0;
static opcat_sub: int = 1;
static opcat_mult: int = 2;
static opcat_shift: int = 3;
static opcat_rel: int = 4;
static opcat_eq: int = 5;
static opcat_bit: int = 6;
static opcat_logic: int = 7;
static opcat_mod: int = 8;
fn opcat(op: ast::BinOp) -> int {
match op {
ast::BiAdd => opcat_add,
ast::BiSub => opcat_sub,
ast::BiMul => opcat_mult,
ast::BiDiv => opcat_mult,
ast::BiRem => opcat_mod,
ast::BiAnd => opcat_logic,
ast::BiOr => opcat_logic,
ast::BiBitXor => opcat_bit,
ast::BiBitAnd => opcat_bit,
ast::BiBitOr => opcat_bit,
ast::BiShl => opcat_shift,
ast::BiShr => opcat_shift,
ast::BiEq => opcat_eq,
ast::BiNe => opcat_eq,
ast::BiLt => opcat_rel,
ast::BiLe => opcat_rel,
ast::BiGe => opcat_rel,
ast::BiGt => opcat_rel
}
}
fn tycat<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> int {
if type_is_simd(cx, ty) {
return tycat(cx, simd_type(cx, ty))
}
match ty.sty {
ty_char => tycat_char,
ty_bool => tycat_bool,
ty_int(_) | ty_uint(_) | ty_infer(IntVar(_)) => tycat_int,
ty_float(_) | ty_infer(FloatVar(_)) => tycat_float,
ty_ptr(_) => tycat_raw_ptr,
_ => tycat_other
}
}
static t: bool = true;
static f: bool = false;
let tbl = [
// +, -, *, shift, rel, ==, bit, logic, mod
/*other*/ [f, f, f, f, f, f, f, f, f],
/*bool*/ [f, f, f, f, t, t, t, t, f],
/*char*/ [f, f, f, f, t, t, f, f, f],
/*int*/ [t, t, t, t, t, t, t, f, t],
/*float*/ [t, t, t, f, t, t, f, f, f],
/*bot*/ [t, t, t, t, t, t, t, t, t],
/*raw ptr*/ [f, f, f, f, t, t, f, f, f]];
return tbl[tycat(cx, ty) as uint ][opcat(op) as uint];
}
/// Returns an equivalent type with all the typedefs and self regions removed.
pub fn normalize_ty<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
let u = TypeNormalizer(cx).fold_ty(ty);
return u;
struct TypeNormalizer<'a, 'tcx: 'a>(&'a ctxt<'tcx>);
impl<'a, 'tcx> TypeFolder<'tcx> for TypeNormalizer<'a, 'tcx> {
fn tcx(&self) -> &ctxt<'tcx> { let TypeNormalizer(c) = *self; c }
fn fold_ty(&mut self, ty: Ty<'tcx>) -> Ty<'tcx> {
match self.tcx().normalized_cache.borrow().get(&ty).cloned() {
None => {}
Some(u) => return u
}
let t_norm = ty_fold::super_fold_ty(self, ty);
self.tcx().normalized_cache.borrow_mut().insert(ty, t_norm);
return t_norm;
}
fn fold_region(&mut self, _: ty::Region) -> ty::Region {
ty::ReStatic
}
fn fold_substs(&mut self,
substs: &subst::Substs<'tcx>)
-> subst::Substs<'tcx> {
subst::Substs { regions: subst::ErasedRegions,
types: substs.types.fold_with(self) }
}
}
}
// Returns the repeat count for a repeating vector expression.
pub fn eval_repeat_count(tcx: &ctxt, count_expr: &ast::Expr) -> uint {
match const_eval::eval_const_expr_partial(tcx, count_expr) {
Ok(val) => {
let found = match val {
const_eval::const_uint(count) => return count as uint,
const_eval::const_int(count) if count >= 0 => return count as uint,
const_eval::const_int(_) =>
"negative integer",
const_eval::const_float(_) =>
"float",
const_eval::const_str(_) =>
"string",
const_eval::const_bool(_) =>
"boolean",
const_eval::const_binary(_) =>
"binary array"
};
tcx.sess.span_err(count_expr.span, format!(
"expected positive integer for repeat count, found {}",
found)[]);
}
Err(_) => {
let found = match count_expr.node {
ast::ExprPath(ast::Path {
global: false,
ref segments,
..
}) if segments.len() == 1 =>
"variable",
_ =>
"non-constant expression"
};
tcx.sess.span_err(count_expr.span, format!(
"expected constant integer for repeat count, found {}",
found)[]);
}
}
0
}
// Iterate over a type parameter's bounded traits and any supertraits
// of those traits, ignoring kinds.
// Here, the supertraits are the transitive closure of the supertrait
// relation on the supertraits from each bounded trait's constraint
// list.
pub fn each_bound_trait_and_supertraits<'tcx, F>(tcx: &ctxt<'tcx>,
bounds: &[PolyTraitRef<'tcx>],
mut f: F)
-> bool where
F: FnMut(PolyTraitRef<'tcx>) -> bool,
{
for bound_trait_ref in traits::transitive_bounds(tcx, bounds) {
if !f(bound_trait_ref) {
return false;
}
}
return true;
}
pub fn object_region_bounds<'tcx>(
tcx: &ctxt<'tcx>,
opt_principal: Option<&PolyTraitRef<'tcx>>, // None for closures
others: BuiltinBounds)
-> Vec<ty::Region>
{
// Since we don't actually *know* the self type for an object,
// this "open(err)" serves as a kind of dummy standin -- basically
// a skolemized type.
let open_ty = ty::mk_infer(tcx, FreshTy(0));
let opt_trait_ref = opt_principal.map_or(Vec::new(), |principal| {
// Note that we preserve the overall binding levels here.
assert!(!open_ty.has_escaping_regions());
let substs = tcx.mk_substs(principal.0.substs.with_self_ty(open_ty));
vec!(ty::Binder(Rc::new(ty::TraitRef::new(principal.0.def_id, substs))))
});
let param_bounds = ty::ParamBounds {
region_bounds: Vec::new(),
builtin_bounds: others,
trait_bounds: opt_trait_ref,
projection_bounds: Vec::new(), // not relevant to computing region bounds
};
let predicates = ty::predicates(tcx, open_ty, &param_bounds);
ty::required_region_bounds(tcx, open_ty, predicates)
}
/// Given a set of predicates that apply to an object type, returns
/// the region bounds that the (erased) `Self` type must
/// outlive. Precisely *because* the `Self` type is erased, the
/// parameter `erased_self_ty` must be supplied to indicate what type
/// has been used to represent `Self` in the predicates
/// themselves. This should really be a unique type; `FreshTy(0)` is a
/// popular choice (see `object_region_bounds` above).
///
/// Requires that trait definitions have been processed so that we can
/// elaborate predicates and walk supertraits.
pub fn required_region_bounds<'tcx>(tcx: &ctxt<'tcx>,
erased_self_ty: Ty<'tcx>,
predicates: Vec<ty::Predicate<'tcx>>)
-> Vec<ty::Region>
{
debug!("required_region_bounds(erased_self_ty={}, predicates={})",
erased_self_ty.repr(tcx),
predicates.repr(tcx));
assert!(!erased_self_ty.has_escaping_regions());
traits::elaborate_predicates(tcx, predicates)
.filter_map(|predicate| {
match predicate {
ty::Predicate::Projection(..) |
ty::Predicate::Trait(..) |
ty::Predicate::Equate(..) |
ty::Predicate::RegionOutlives(..) => {
None
}
ty::Predicate::TypeOutlives(ty::Binder(ty::OutlivesPredicate(t, r))) => {
// Search for a bound of the form `erased_self_ty
// : 'a`, but be wary of something like `for<'a>
// erased_self_ty : 'a` (we interpret a
// higher-ranked bound like that as 'static,
// though at present the code in `fulfill.rs`
// considers such bounds to be unsatisfiable, so
// it's kind of a moot point since you could never
// construct such an object, but this seems
// correct even if that code changes).
if t == erased_self_ty && !r.has_escaping_regions() {
if r.has_escaping_regions() {
Some(ty::ReStatic)
} else {
Some(r)
}
} else {
None
}
}
}
})
.collect()
}
pub fn get_tydesc_ty<'tcx>(tcx: &ctxt<'tcx>) -> Result<Ty<'tcx>, String> {
tcx.lang_items.require(TyDescStructLangItem).map(|tydesc_lang_item| {
tcx.intrinsic_defs.borrow().get(&tydesc_lang_item).cloned()
.expect("Failed to resolve TyDesc")
})
}
pub fn item_variances(tcx: &ctxt, item_id: ast::DefId) -> Rc<ItemVariances> {
lookup_locally_or_in_crate_store(
"item_variance_map", item_id, &mut *tcx.item_variance_map.borrow_mut(),
|| Rc::new(csearch::get_item_variances(&tcx.sess.cstore, item_id)))
}
/// Records a trait-to-implementation mapping.
pub fn record_trait_implementation(tcx: &ctxt,
trait_def_id: DefId,
impl_def_id: DefId) {
match tcx.trait_impls.borrow().get(&trait_def_id) {
Some(impls_for_trait) => {
impls_for_trait.borrow_mut().push(impl_def_id);
return;
}
None => {}
}
tcx.trait_impls.borrow_mut().insert(trait_def_id, Rc::new(RefCell::new(vec!(impl_def_id))));
}
/// Populates the type context with all the implementations for the given type
/// if necessary.
pub fn populate_implementations_for_type_if_necessary(tcx: &ctxt,
type_id: ast::DefId) {
if type_id.krate == LOCAL_CRATE {
return
}
if tcx.populated_external_types.borrow().contains(&type_id) {
return
}
let mut inherent_impls = Vec::new();
csearch::each_implementation_for_type(&tcx.sess.cstore, type_id,
|impl_def_id| {
let impl_items = csearch::get_impl_items(&tcx.sess.cstore,
impl_def_id);
// Record the trait->implementation mappings, if applicable.
let associated_traits = csearch::get_impl_trait(tcx, impl_def_id);
for trait_ref in associated_traits.iter() {
record_trait_implementation(tcx, trait_ref.def_id, impl_def_id);
}
// 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.iter() {
let method_def_id = impl_item_def_id.def_id();
match impl_or_trait_item(tcx, method_def_id) {
MethodTraitItem(method) => {
for &source in method.provided_source.iter() {
tcx.provided_method_sources
.borrow_mut()
.insert(method_def_id, source);
}
}
TypeTraitItem(_) => {}
}
}
// Store the implementation info.
tcx.impl_items.borrow_mut().insert(impl_def_id, impl_items);
// If this is an inherent implementation, record it.
if associated_traits.is_none() {
inherent_impls.push(impl_def_id);
}
});
tcx.inherent_impls.borrow_mut().insert(type_id, Rc::new(inherent_impls));
tcx.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(
tcx: &ctxt,
trait_id: ast::DefId) {
if trait_id.krate == LOCAL_CRATE {
return
}
if tcx.populated_external_traits.borrow().contains(&trait_id) {
return
}
csearch::each_implementation_for_trait(&tcx.sess.cstore, trait_id,
|implementation_def_id| {
let impl_items = csearch::get_impl_items(&tcx.sess.cstore, implementation_def_id);
// Record the trait->implementation mapping.
record_trait_implementation(tcx, trait_id, implementation_def_id);
// 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.iter() {
let method_def_id = impl_item_def_id.def_id();
match impl_or_trait_item(tcx, method_def_id) {
MethodTraitItem(method) => {
for &source in method.provided_source.iter() {
tcx.provided_method_sources
.borrow_mut()
.insert(method_def_id, source);
}
}
TypeTraitItem(_) => {}
}
}
// Store the implementation info.
tcx.impl_items.borrow_mut().insert(implementation_def_id, impl_items);
});
tcx.populated_external_traits.borrow_mut().insert(trait_id);
}
/// 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(tcx: &ctxt,
def_id: ast::DefId) -> Option<ast::DefId> {
let node = match tcx.map.find(def_id.node) {
Some(node) => node,
None => return None
};
match node {
ast_map::NodeItem(item) => {
match item.node {
ast::ItemImpl(_, _, Some(ref trait_ref), _, _) => {
Some(node_id_to_trait_ref(tcx, trait_ref.ref_id).def_id)
}
_ => None
}
}
_ => None
}
}
/// 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(tcx: &ctxt, def_id: ast::DefId)
-> Option<ast::DefId> {
if def_id.krate != LOCAL_CRATE {
return match csearch::get_impl_or_trait_item(tcx,
def_id).container() {
TraitContainer(_) => None,
ImplContainer(def_id) => Some(def_id),
};
}
match tcx.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 (either a
/// default method or an implementation of a trait method), return the ID of
/// the trait that the method belongs to. Otherwise, return `None`.
pub fn trait_of_item(tcx: &ctxt, def_id: ast::DefId) -> Option<ast::DefId> {
if def_id.krate != LOCAL_CRATE {
return csearch::get_trait_of_item(&tcx.sess.cstore, def_id, tcx);
}
match tcx.impl_or_trait_items.borrow().get(&def_id).cloned() {
Some(impl_or_trait_item) => {
match impl_or_trait_item.container() {
TraitContainer(def_id) => Some(def_id),
ImplContainer(def_id) => trait_id_of_impl(tcx, def_id),
}
}
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(tcx: &ctxt, def_id: ast::DefId)
-> Option<ImplOrTraitItemId> {
let impl_item = match tcx.impl_or_trait_items.borrow().get(&def_id) {
Some(m) => m.clone(),
None => return None,
};
let name = impl_item.name();
match trait_of_item(tcx, def_id) {
Some(trait_did) => {
let trait_items = ty::trait_items(tcx, trait_did);
trait_items.iter()
.position(|m| m.name() == name)
.map(|idx| ty::trait_item(tcx, trait_did, idx).id())
}
None => None
}
}
/// Creates a hash of the type `Ty` which will be the same no matter what crate
/// context it's calculated within. This is used by the `type_id` intrinsic.
pub fn hash_crate_independent<'tcx>(tcx: &ctxt<'tcx>, ty: Ty<'tcx>, svh: &Svh) -> u64 {
let mut state = sip::SipState::new();
helper(tcx, ty, svh, &mut state);
return state.result();
fn helper<'tcx>(tcx: &ctxt<'tcx>, ty: Ty<'tcx>, svh: &Svh, state: &mut sip::SipState) {
macro_rules! byte( ($b:expr) => { ($b as u8).hash(state) } );
macro_rules! hash( ($e:expr) => { $e.hash(state) } );
let region = |&: state: &mut sip::SipState, r: Region| {
match r {
ReStatic => {}
ReLateBound(db, BrAnon(i)) => {
db.hash(state);
i.hash(state);
}
ReEmpty |
ReEarlyBound(..) |
ReLateBound(..) |
ReFree(..) |
ReScope(..) |
ReInfer(..) => {
tcx.sess.bug("unexpected region found when hashing a type")
}
}
};
let did = |&: state: &mut sip::SipState, did: DefId| {
let h = if ast_util::is_local(did) {
svh.clone()
} else {
tcx.sess.cstore.get_crate_hash(did.krate)
};
h.as_str().hash(state);
did.node.hash(state);
};
let mt = |&: state: &mut sip::SipState, mt: mt| {
mt.mutbl.hash(state);
};
let fn_sig = |&: state: &mut sip::SipState, sig: &Binder<FnSig<'tcx>>| {
let sig = anonymize_late_bound_regions(tcx, sig);
for a in sig.inputs.iter() { helper(tcx, *a, svh, state); }
if let ty::FnConverging(output) = sig.output {
helper(tcx, output, svh, state);
}
};
maybe_walk_ty(ty, |ty| {
match ty.sty {
ty_bool => byte!(2),
ty_char => byte!(3),
ty_int(i) => {
byte!(4);
hash!(i);
}
ty_uint(u) => {
byte!(5);
hash!(u);
}
ty_float(f) => {
byte!(6);
hash!(f);
}
ty_str => {
byte!(7);
}
ty_enum(d, _) => {
byte!(8);
did(state, d);
}
ty_uniq(_) => {
byte!(9);
}
ty_vec(_, Some(n)) => {
byte!(10);
n.hash(state);
}
ty_vec(_, None) => {
byte!(11);
}
ty_ptr(m) => {
byte!(12);
mt(state, m);
}
ty_rptr(r, m) => {
byte!(13);
region(state, *r);
mt(state, m);
}
ty_bare_fn(opt_def_id, ref b) => {
byte!(14);
hash!(opt_def_id);
hash!(b.unsafety);
hash!(b.abi);
fn_sig(state, &b.sig);
return false;
}
ty_closure(ref c) => {
byte!(15);
hash!(c.unsafety);
hash!(c.onceness);
hash!(c.bounds);
match c.store {
UniqTraitStore => byte!(0),
RegionTraitStore(r, m) => {
byte!(1);
region(state, r);
assert_eq!(m, ast::MutMutable);
}
}
fn_sig(state, &c.sig);
return false;
}
ty_trait(ref data) => {
byte!(17);
did(state, data.principal_def_id());
hash!(data.bounds);
let principal = anonymize_late_bound_regions(tcx, &data.principal);
for subty in principal.substs.types.iter() {
helper(tcx, *subty, svh, state);
}
return false;
}
ty_struct(d, _) => {
byte!(18);
did(state, d);
}
ty_tup(ref inner) => {
byte!(19);
hash!(inner.len());
}
ty_param(p) => {
byte!(20);
hash!(p.space);
hash!(p.idx);
hash!(token::get_name(p.name));
}
ty_open(_) => byte!(22),
ty_infer(_) => unreachable!(),
ty_err => byte!(23),
ty_unboxed_closure(d, r, _) => {
byte!(24);
did(state, d);
region(state, *r);
}
ty_projection(ref data) => {
byte!(25);
did(state, data.trait_ref.def_id);
hash!(token::get_name(data.item_name));
}
}
true
});
}
}
impl Variance {
pub fn to_string(self) -> &'static str {
match self {
Covariant => "+",
Contravariant => "-",
Invariant => "o",
Bivariant => "*",
}
}
}
/// 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<'tcx>() -> ParameterEnvironment<'tcx> {
ty::ParameterEnvironment { free_substs: Substs::empty(),
caller_bounds: GenericBounds::empty(),
implicit_region_bound: ty::ReEmpty,
selection_cache: traits::SelectionCache::new(), }
}
/// See `ParameterEnvironment` struct def'n for details
pub fn construct_parameter_environment<'tcx>(
tcx: &ctxt<'tcx>,
generics: &ty::Generics<'tcx>,
free_id: ast::NodeId)
-> ParameterEnvironment<'tcx>
{
//
// Construct the free substs.
//
// map T => T
let mut types = VecPerParamSpace::empty();
push_types_from_defs(tcx, &mut types, generics.types.as_slice());
// map bound 'a => free 'a
let mut regions = VecPerParamSpace::empty();
push_region_params(&mut regions, free_id, generics.regions.as_slice());
let free_substs = Substs {
types: types,
regions: subst::NonerasedRegions(regions)
};
let free_id_scope = region::CodeExtent::from_node_id(free_id);
//
// Compute the bounds on Self and the type parameters.
//
let bounds = generics.to_bounds(tcx, &free_substs);
let bounds = liberate_late_bound_regions(tcx, free_id_scope, &ty::Binder(bounds));
//
// Compute region bounds. For now, these relations are stored in a
// global table on the tcx, so just enter them there. I'm not
// crazy about this scheme, but it's convenient, at least.
//
record_region_bounds(tcx, &bounds);
debug!("construct_parameter_environment: free_id={} free_subst={} bounds={}",
free_id,
free_substs.repr(tcx),
bounds.repr(tcx));
return ty::ParameterEnvironment {
free_substs: free_substs,
implicit_region_bound: ty::ReScope(free_id_scope),
caller_bounds: bounds,
selection_cache: traits::SelectionCache::new(),
};
fn push_region_params(regions: &mut VecPerParamSpace<ty::Region>,
free_id: ast::NodeId,
region_params: &[RegionParameterDef])
{
for r in region_params.iter() {
regions.push(r.space, ty::free_region_from_def(free_id, r));
}
}
fn push_types_from_defs<'tcx>(tcx: &ty::ctxt<'tcx>,
types: &mut VecPerParamSpace<Ty<'tcx>>,
defs: &[TypeParameterDef<'tcx>]) {
for def in defs.iter() {
debug!("construct_parameter_environment(): push_types_from_defs: def={}",
def.repr(tcx));
let ty = ty::mk_param_from_def(tcx, def);
types.push(def.space, ty);
}
}
fn record_region_bounds<'tcx>(tcx: &ty::ctxt<'tcx>, bounds: &GenericBounds<'tcx>) {
debug!("record_region_bounds(bounds={})", bounds.repr(tcx));
for predicate in bounds.predicates.iter() {
match *predicate {
Predicate::Projection(..) |
Predicate::Trait(..) |
Predicate::Equate(..) |
Predicate::TypeOutlives(..) => {
// No region bounds here
}
Predicate::RegionOutlives(ty::Binder(ty::OutlivesPredicate(r_a, r_b))) => {
match (r_a, r_b) {
(ty::ReFree(fr_a), ty::ReFree(fr_b)) => {
// Record that `'a:'b`. Or, put another way, `'b <= 'a`.
tcx.region_maps.relate_free_regions(fr_b, fr_a);
}
_ => {
// All named regions are instantiated with free regions.
tcx.sess.bug(
format!("record_region_bounds: non free region: {} / {}",
r_a.repr(tcx),
r_b.repr(tcx)).as_slice());
}
}
}
}
}
}
}
impl BorrowKind {
pub fn from_mutbl(m: ast::Mutability) -> BorrowKind {
match m {
ast::MutMutable => MutBorrow,
ast::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) -> ast::Mutability {
match self {
MutBorrow => ast::MutMutable,
ImmBorrow => ast::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 => ast::MutMutable,
}
}
pub fn to_user_str(&self) -> &'static str {
match *self {
MutBorrow => "mutable",
ImmBorrow => "immutable",
UniqueImmBorrow => "uniquely immutable",
}
}
}
impl<'tcx> mc::Typer<'tcx> for ty::ctxt<'tcx> {
fn tcx<'a>(&'a self) -> &'a ty::ctxt<'tcx> {
self
}
fn node_ty(&self, id: ast::NodeId) -> Ty<'tcx> {
ty::node_id_to_type(self, id)
}
fn expr_ty_adjusted(&self, expr: &ast::Expr) -> Ty<'tcx> {
ty::expr_ty_adjusted(self, expr)
}
fn node_method_ty(&self, method_call: ty::MethodCall) -> Option<Ty<'tcx>> {
self.method_map.borrow().get(&method_call).map(|method| method.ty)
}
fn node_method_origin(&self, method_call: ty::MethodCall)
-> Option<ty::MethodOrigin<'tcx>>
{
self.method_map.borrow().get(&method_call).map(|method| method.origin.clone())
}
fn adjustments<'a>(&'a self) -> &'a RefCell<NodeMap<ty::AutoAdjustment<'tcx>>> {
&self.adjustments
}
fn is_method_call(&self, id: ast::NodeId) -> bool {
self.method_map.borrow().contains_key(&MethodCall::expr(id))
}
fn temporary_scope(&self, rvalue_id: ast::NodeId) -> Option<region::CodeExtent> {
self.region_maps.temporary_scope(rvalue_id)
}
fn upvar_borrow(&self, upvar_id: ty::UpvarId) -> Option<ty::UpvarBorrow> {
Some(self.upvar_borrow_map.borrow()[upvar_id].clone())
}
fn capture_mode(&self, closure_expr_id: ast::NodeId)
-> ast::CaptureClause {
self.capture_modes.borrow()[closure_expr_id].clone()
}
}
impl<'tcx> UnboxedClosureTyper<'tcx> for ty::ctxt<'tcx> {
fn unboxed_closure_kind(&self,
def_id: ast::DefId)
-> ty::UnboxedClosureKind
{
self.unboxed_closures.borrow()[def_id].kind
}
fn unboxed_closure_type(&self,
def_id: ast::DefId,
substs: &subst::Substs<'tcx>)
-> ty::ClosureTy<'tcx>
{
self.unboxed_closures.borrow()[def_id].closure_type.subst(self, substs)
}
fn unboxed_closure_upvars(&self,
def_id: ast::DefId,
substs: &Substs<'tcx>)
-> Option<Vec<UnboxedClosureUpvar<'tcx>>>
{
unboxed_closure_upvars(self, def_id, substs)
}
}
/// The category of explicit self.
#[deriving(Clone, Copy, Eq, PartialEq, Show)]
pub enum ExplicitSelfCategory {
StaticExplicitSelfCategory,
ByValueExplicitSelfCategory,
ByReferenceExplicitSelfCategory(Region, ast::Mutability),
ByBoxExplicitSelfCategory,
}
/// Pushes all the lifetimes in the given type onto the given list. A
/// "lifetime in a type" is a lifetime specified by a reference or a lifetime
/// in a list of type substitutions. This does *not* traverse into nominal
/// types, nor does it resolve fictitious types.
pub fn accumulate_lifetimes_in_type(accumulator: &mut Vec<ty::Region>,
ty: Ty) {
walk_ty(ty, |ty| {
match ty.sty {
ty_rptr(region, _) => {
accumulator.push(*region)
}
ty_trait(ref t) => {
accumulator.push_all(t.principal.0.substs.regions().as_slice());
}
ty_enum(_, substs) |
ty_struct(_, substs) => {
accum_substs(accumulator, substs);
}
ty_closure(ref closure_ty) => {
match closure_ty.store {
RegionTraitStore(region, _) => accumulator.push(region),
UniqTraitStore => {}
}
}
ty_unboxed_closure(_, region, substs) => {
accumulator.push(*region);
accum_substs(accumulator, substs);
}
ty_bool |
ty_char |
ty_int(_) |
ty_uint(_) |
ty_float(_) |
ty_uniq(_) |
ty_str |
ty_vec(_, _) |
ty_ptr(_) |
ty_bare_fn(..) |
ty_tup(_) |
ty_projection(_) |
ty_param(_) |
ty_infer(_) |
ty_open(_) |
ty_err => {
}
}
});
fn accum_substs(accumulator: &mut Vec<Region>, substs: &Substs) {
match substs.regions {
subst::ErasedRegions => {}
subst::NonerasedRegions(ref regions) => {
for region in regions.iter() {
accumulator.push(*region)
}
}
}
}
}
/// A free variable referred to in a function.
#[deriving(Copy, RustcEncodable, RustcDecodable)]
pub struct Freevar {
/// The variable being accessed free.
pub def: def::Def,
// First span where it is accessed (there can be multiple).
pub span: Span
}
pub type FreevarMap = NodeMap<Vec<Freevar>>;
pub type CaptureModeMap = NodeMap<ast::CaptureClause>;
// Trait method resolution
pub type TraitMap = NodeMap<Vec<DefId>>;
// Map from the NodeId of a glob import to a list of items which are actually
// imported.
pub type GlobMap = HashMap<NodeId, HashSet<Name>>;
pub fn with_freevars<T, F>(tcx: &ty::ctxt, fid: ast::NodeId, f: F) -> T where
F: FnOnce(&[Freevar]) -> T,
{
match tcx.freevars.borrow().get(&fid) {
None => f(&[]),
Some(d) => f(d[])
}
}
impl<'tcx> AutoAdjustment<'tcx> {
pub fn is_identity(&self) -> bool {
match *self {
AdjustAddEnv(..) => false,
AdjustReifyFnPointer(..) => false,
AdjustDerefRef(ref r) => r.is_identity(),
}
}
}
impl<'tcx> AutoDerefRef<'tcx> {
pub fn is_identity(&self) -> bool {
self.autoderefs == 0 && self.autoref.is_none()
}
}
/// Replace any late-bound regions bound in `value` with free variants attached to scope-id
/// `scope_id`.
pub fn liberate_late_bound_regions<'tcx, T>(
tcx: &ty::ctxt<'tcx>,
scope: region::CodeExtent,
value: &Binder<T>)
-> T
where T : TypeFoldable<'tcx> + Repr<'tcx>
{
replace_late_bound_regions(
tcx, value,
|br, _| ty::ReFree(ty::FreeRegion{scope: scope, bound_region: br})).0
}
pub fn count_late_bound_regions<'tcx, T>(
tcx: &ty::ctxt<'tcx>,
value: &Binder<T>)
-> uint
where T : TypeFoldable<'tcx> + Repr<'tcx>
{
let (_, skol_map) = replace_late_bound_regions(tcx, value, |_, _| ty::ReStatic);
skol_map.len()
}
pub fn binds_late_bound_regions<'tcx, T>(
tcx: &ty::ctxt<'tcx>,
value: &Binder<T>)
-> bool
where T : TypeFoldable<'tcx> + Repr<'tcx>
{
count_late_bound_regions(tcx, value) > 0
}
/// Replace any late-bound regions bound in `value` with `'static`. Useful in trans but also
/// method lookup and a few other places where precise region relationships are not required.
pub fn erase_late_bound_regions<'tcx, T>(
tcx: &ty::ctxt<'tcx>,
value: &Binder<T>)
-> T
where T : TypeFoldable<'tcx> + Repr<'tcx>
{
replace_late_bound_regions(tcx, value, |_, _| ty::ReStatic).0
}
/// Rewrite any late-bound regions so that they are anonymous. Region numbers are
/// assigned starting at 1 and increasing monotonically in the order traversed
/// by the fold operation.
///
/// The chief purpose of this function is to canonicalize regions so that two
/// `FnSig`s or `TraitRef`s which are equivalent up to region naming will become
/// structurally identical. For example, `for<'a, 'b> fn(&'a int, &'b int)` and
/// `for<'a, 'b> fn(&'b int, &'a int)` will become identical after anonymization.
pub fn anonymize_late_bound_regions<'tcx, T>(
tcx: &ctxt<'tcx>,
sig: &Binder<T>)
-> T
where T : TypeFoldable<'tcx> + Repr<'tcx>,
{
let mut counter = 0;
replace_late_bound_regions(tcx, sig, |_, db| {
counter += 1;
ReLateBound(db, BrAnon(counter))
}).0
}
/// Replaces the late-bound-regions in `value` that are bound by `value`.
pub fn replace_late_bound_regions<'tcx, T, F>(
tcx: &ty::ctxt<'tcx>,
binder: &Binder<T>,
mut mapf: F)
-> (T, FnvHashMap<ty::BoundRegion,ty::Region>)
where T : TypeFoldable<'tcx> + Repr<'tcx>,
F : FnMut(BoundRegion, DebruijnIndex) -> ty::Region,
{
debug!("replace_late_bound_regions({})", binder.repr(tcx));
let mut map = FnvHashMap::new();
// Note: fold the field `0`, not the binder, so that late-bound
// regions bound by `binder` are considered free.
let value = ty_fold::fold_regions(tcx, &binder.0, |region, current_depth| {
debug!("region={}", region.repr(tcx));
match region {
ty::ReLateBound(debruijn, br) if debruijn.depth == current_depth => {
* match map.entry(br) {
Vacant(entry) => entry.set(mapf(br, debruijn)),
Occupied(entry) => entry.into_mut(),
}
}
_ => {
region
}
}
});
debug!("resulting map: {} value: {}", map, value.repr(tcx));
(value, map)
}
impl DebruijnIndex {
pub fn new(depth: u32) -> DebruijnIndex {
assert!(depth > 0);
DebruijnIndex { depth: depth }
}
pub fn shifted(&self, amount: u32) -> DebruijnIndex {
DebruijnIndex { depth: self.depth + amount }
}
}
impl<'tcx> Repr<'tcx> for AutoAdjustment<'tcx> {
fn repr(&self, tcx: &ctxt<'tcx>) -> String {
match *self {
AdjustAddEnv(def_id, ref trait_store) => {
format!("AdjustAddEnv({},{})", def_id.repr(tcx), trait_store)
}
AdjustReifyFnPointer(def_id) => {
format!("AdjustAddEnv({})", def_id.repr(tcx))
}
AdjustDerefRef(ref data) => {
data.repr(tcx)
}
}
}
}
impl<'tcx> Repr<'tcx> for UnsizeKind<'tcx> {
fn repr(&self, tcx: &ctxt<'tcx>) -> String {
match *self {
UnsizeLength(n) => format!("UnsizeLength({})", n),
UnsizeStruct(ref k, n) => format!("UnsizeStruct({},{})", k.repr(tcx), n),
UnsizeVtable(ref a, ref b) => format!("UnsizeVtable({},{})", a.repr(tcx), b.repr(tcx)),
}
}
}
impl<'tcx> Repr<'tcx> for AutoDerefRef<'tcx> {
fn repr(&self, tcx: &ctxt<'tcx>) -> String {
format!("AutoDerefRef({}, {})", self.autoderefs, self.autoref.repr(tcx))
}
}
impl<'tcx> Repr<'tcx> for AutoRef<'tcx> {
fn repr(&self, tcx: &ctxt<'tcx>) -> String {
match *self {
AutoPtr(a, b, ref c) => {
format!("AutoPtr({},{},{})", a.repr(tcx), b, c.repr(tcx))
}
AutoUnsize(ref a) => {
format!("AutoUnsize({})", a.repr(tcx))
}
AutoUnsizeUniq(ref a) => {
format!("AutoUnsizeUniq({})", a.repr(tcx))
}
AutoUnsafe(ref a, ref b) => {
format!("AutoUnsafe({},{})", a, b.repr(tcx))
}
}
}
}
impl<'tcx> Repr<'tcx> for TyTrait<'tcx> {
fn repr(&self, tcx: &ctxt<'tcx>) -> String {
format!("TyTrait({},{})",
self.principal.repr(tcx),
self.bounds.repr(tcx))
}
}
impl<'tcx> Repr<'tcx> for ty::Predicate<'tcx> {
fn repr(&self, tcx: &ctxt<'tcx>) -> String {
match *self {
Predicate::Trait(ref a) => a.repr(tcx),
Predicate::Equate(ref pair) => pair.repr(tcx),
Predicate::RegionOutlives(ref pair) => pair.repr(tcx),
Predicate::TypeOutlives(ref pair) => pair.repr(tcx),
Predicate::Projection(ref pair) => pair.repr(tcx),
}
}
}
impl<'tcx> Repr<'tcx> for vtable_origin<'tcx> {
fn repr(&self, tcx: &ty::ctxt<'tcx>) -> String {
match *self {
vtable_static(def_id, ref tys, ref vtable_res) => {
format!("vtable_static({}:{}, {}, {})",
def_id,
ty::item_path_str(tcx, def_id),
tys.repr(tcx),
vtable_res.repr(tcx))
}
vtable_param(x, y) => {
format!("vtable_param({}, {})", x, y)
}
vtable_unboxed_closure(def_id) => {
format!("vtable_unboxed_closure({})", def_id)
}
vtable_error => {
format!("vtable_error")
}
}
}
}
pub fn make_substs_for_receiver_types<'tcx>(tcx: &ty::ctxt<'tcx>,
trait_ref: &ty::TraitRef<'tcx>,
method: &ty::Method<'tcx>)
-> subst::Substs<'tcx>
{
/*!
* Substitutes the values for the receiver's type parameters
* that are found in method, leaving the method's type parameters
* intact.
*/
let meth_tps: Vec<Ty> =
method.generics.types.get_slice(subst::FnSpace)
.iter()
.map(|def| ty::mk_param_from_def(tcx, def))
.collect();
let meth_regions: Vec<ty::Region> =
method.generics.regions.get_slice(subst::FnSpace)
.iter()
.map(|def| ty::ReEarlyBound(def.def_id.node, def.space,
def.index, def.name))
.collect();
trait_ref.substs.clone().with_method(meth_tps, meth_regions)
}
#[deriving(Copy)]
pub enum CopyImplementationError {
FieldDoesNotImplementCopy(ast::Name),
VariantDoesNotImplementCopy(ast::Name),
TypeIsStructural,
}
pub fn can_type_implement_copy<'tcx>(tcx: &ctxt<'tcx>,
self_type: Ty<'tcx>,
param_env: &ParameterEnvironment<'tcx>)
-> Result<(),CopyImplementationError> {
match self_type.sty {
ty::ty_struct(struct_did, substs) => {
let fields = ty::struct_fields(tcx, struct_did, substs);
for field in fields.iter() {
if type_moves_by_default(tcx, field.mt.ty, param_env) {
return Err(FieldDoesNotImplementCopy(field.name))
}
}
}
ty::ty_enum(enum_did, substs) => {
let enum_variants = ty::enum_variants(tcx, enum_did);
for variant in enum_variants.iter() {
for variant_arg_type in variant.args.iter() {
let substd_arg_type =
variant_arg_type.subst(tcx, substs);
if type_moves_by_default(tcx,
substd_arg_type,
param_env) {
return Err(VariantDoesNotImplementCopy(variant.name))
}
}
}
}
_ => return Err(TypeIsStructural),
}
Ok(())
}
// FIXME(#20298) -- all of these types basically walk various
// structures to test whether types/regions are reachable with various
// properties. It should be possible to express them in terms of one
// common "walker" trait or something.
pub trait RegionEscape {
fn has_escaping_regions(&self) -> bool {
self.has_regions_escaping_depth(0)
}
fn has_regions_escaping_depth(&self, depth: u32) -> bool;
}
impl<'tcx> RegionEscape for Ty<'tcx> {
fn has_regions_escaping_depth(&self, depth: u32) -> bool {
ty::type_escapes_depth(*self, depth)
}
}
impl<'tcx,T:RegionEscape> RegionEscape for VecPerParamSpace<T> {
fn has_regions_escaping_depth(&self, depth: u32) -> bool {
self.iter_enumerated().any(|(space, _, t)| {
if space == subst::FnSpace {
t.has_regions_escaping_depth(depth+1)
} else {
t.has_regions_escaping_depth(depth)
}
})
}
}
impl<'tcx> RegionEscape for TypeScheme<'tcx> {
fn has_regions_escaping_depth(&self, depth: u32) -> bool {
self.ty.has_regions_escaping_depth(depth) ||
self.generics.has_regions_escaping_depth(depth)
}
}
impl RegionEscape for Region {
fn has_regions_escaping_depth(&self, depth: u32) -> bool {
self.escapes_depth(depth)
}
}
impl<'tcx> RegionEscape for Generics<'tcx> {
fn has_regions_escaping_depth(&self, depth: u32) -> bool {
self.predicates.has_regions_escaping_depth(depth)
}
}
impl<'tcx> RegionEscape for Predicate<'tcx> {
fn has_regions_escaping_depth(&self, depth: u32) -> bool {
match *self {
Predicate::Trait(ref data) => data.has_regions_escaping_depth(depth),
Predicate::Equate(ref data) => data.has_regions_escaping_depth(depth),
Predicate::RegionOutlives(ref data) => data.has_regions_escaping_depth(depth),
Predicate::TypeOutlives(ref data) => data.has_regions_escaping_depth(depth),
Predicate::Projection(ref data) => data.has_regions_escaping_depth(depth),
}
}
}
impl<'tcx> RegionEscape for TraitRef<'tcx> {
fn has_regions_escaping_depth(&self, depth: u32) -> bool {
self.substs.types.iter().any(|t| t.has_regions_escaping_depth(depth)) ||
self.substs.regions.has_regions_escaping_depth(depth)
}
}
impl<'tcx> RegionEscape for subst::RegionSubsts {
fn has_regions_escaping_depth(&self, depth: u32) -> bool {
match *self {
subst::ErasedRegions => false,
subst::NonerasedRegions(ref r) => {
r.iter().any(|t| t.has_regions_escaping_depth(depth))
}
}
}
}
impl<'tcx,T:RegionEscape> RegionEscape for Binder<T> {
fn has_regions_escaping_depth(&self, depth: u32) -> bool {
self.0.has_regions_escaping_depth(depth + 1)
}
}
impl<'tcx> RegionEscape for EquatePredicate<'tcx> {
fn has_regions_escaping_depth(&self, depth: u32) -> bool {
self.0.has_regions_escaping_depth(depth) || self.1.has_regions_escaping_depth(depth)
}
}
impl<'tcx> RegionEscape for TraitPredicate<'tcx> {
fn has_regions_escaping_depth(&self, depth: u32) -> bool {
self.trait_ref.has_regions_escaping_depth(depth)
}
}
impl<T:RegionEscape,U:RegionEscape> RegionEscape for OutlivesPredicate<T,U> {
fn has_regions_escaping_depth(&self, depth: u32) -> bool {
self.0.has_regions_escaping_depth(depth) || self.1.has_regions_escaping_depth(depth)
}
}
impl<'tcx> RegionEscape for ProjectionPredicate<'tcx> {
fn has_regions_escaping_depth(&self, depth: u32) -> bool {
self.projection_ty.has_regions_escaping_depth(depth) ||
self.ty.has_regions_escaping_depth(depth)
}
}
impl<'tcx> RegionEscape for ProjectionTy<'tcx> {
fn has_regions_escaping_depth(&self, depth: u32) -> bool {
self.trait_ref.has_regions_escaping_depth(depth)
}
}
impl<'tcx> Repr<'tcx> for ty::ProjectionPredicate<'tcx> {
fn repr(&self, tcx: &ctxt<'tcx>) -> String {
format!("ProjectionPredicate({}, {})",
self.projection_ty.repr(tcx),
self.ty.repr(tcx))
}
}
pub trait HasProjectionTypes {
fn has_projection_types(&self) -> bool;
}
impl<'tcx,T:HasProjectionTypes> HasProjectionTypes for Vec<T> {
fn has_projection_types(&self) -> bool {
self.iter().any(|p| p.has_projection_types())
}
}
impl<'tcx,T:HasProjectionTypes> HasProjectionTypes for VecPerParamSpace<T> {
fn has_projection_types(&self) -> bool {
self.iter().any(|p| p.has_projection_types())
}
}
impl<'tcx> HasProjectionTypes for ClosureTy<'tcx> {
fn has_projection_types(&self) -> bool {
self.sig.has_projection_types()
}
}
impl<'tcx> HasProjectionTypes for UnboxedClosureUpvar<'tcx> {
fn has_projection_types(&self) -> bool {
self.ty.has_projection_types()
}
}
impl<'tcx> HasProjectionTypes for ty::GenericBounds<'tcx> {
fn has_projection_types(&self) -> bool {
self.predicates.has_projection_types()
}
}
impl<'tcx> HasProjectionTypes for Predicate<'tcx> {
fn has_projection_types(&self) -> bool {
match *self {
Predicate::Trait(ref data) => data.has_projection_types(),
Predicate::Equate(ref data) => data.has_projection_types(),
Predicate::RegionOutlives(ref data) => data.has_projection_types(),
Predicate::TypeOutlives(ref data) => data.has_projection_types(),
Predicate::Projection(ref data) => data.has_projection_types(),
}
}
}
impl<'tcx> HasProjectionTypes for TraitPredicate<'tcx> {
fn has_projection_types(&self) -> bool {
self.trait_ref.has_projection_types()
}
}
impl<'tcx> HasProjectionTypes for EquatePredicate<'tcx> {
fn has_projection_types(&self) -> bool {
self.0.has_projection_types() || self.1.has_projection_types()
}
}
impl HasProjectionTypes for Region {
fn has_projection_types(&self) -> bool {
false
}
}
impl<T:HasProjectionTypes,U:HasProjectionTypes> HasProjectionTypes for OutlivesPredicate<T,U> {
fn has_projection_types(&self) -> bool {
self.0.has_projection_types() || self.1.has_projection_types()
}
}
impl<'tcx> HasProjectionTypes for ProjectionPredicate<'tcx> {
fn has_projection_types(&self) -> bool {
self.projection_ty.has_projection_types() || self.ty.has_projection_types()
}
}
impl<'tcx> HasProjectionTypes for ProjectionTy<'tcx> {
fn has_projection_types(&self) -> bool {
self.trait_ref.has_projection_types()
}
}
impl<'tcx> HasProjectionTypes for Ty<'tcx> {
fn has_projection_types(&self) -> bool {
ty::type_has_projection(*self)
}
}
impl<'tcx> HasProjectionTypes for TraitRef<'tcx> {
fn has_projection_types(&self) -> bool {
self.substs.has_projection_types()
}
}
impl<'tcx> HasProjectionTypes for subst::Substs<'tcx> {
fn has_projection_types(&self) -> bool {
self.types.iter().any(|t| t.has_projection_types())
}
}
impl<'tcx,T> HasProjectionTypes for Option<T>
where T : HasProjectionTypes
{
fn has_projection_types(&self) -> bool {
self.iter().any(|t| t.has_projection_types())
}
}
impl<'tcx,T> HasProjectionTypes for Rc<T>
where T : HasProjectionTypes
{
fn has_projection_types(&self) -> bool {
(**self).has_projection_types()
}
}
impl<'tcx,T> HasProjectionTypes for Box<T>
where T : HasProjectionTypes
{
fn has_projection_types(&self) -> bool {
(**self).has_projection_types()
}
}
impl<T> HasProjectionTypes for Binder<T>
where T : HasProjectionTypes
{
fn has_projection_types(&self) -> bool {
self.0.has_projection_types()
}
}
impl<'tcx> HasProjectionTypes for FnOutput<'tcx> {
fn has_projection_types(&self) -> bool {
match *self {
FnConverging(t) => t.has_projection_types(),
FnDiverging => false,
}
}
}
impl<'tcx> HasProjectionTypes for FnSig<'tcx> {
fn has_projection_types(&self) -> bool {
self.inputs.iter().any(|t| t.has_projection_types()) ||
self.output.has_projection_types()
}
}
impl<'tcx> HasProjectionTypes for BareFnTy<'tcx> {
fn has_projection_types(&self) -> bool {
self.sig.has_projection_types()
}
}
pub trait ReferencesError {
fn references_error(&self) -> bool;
}
impl<T:ReferencesError> ReferencesError for Binder<T> {
fn references_error(&self) -> bool {
self.0.references_error()
}
}
impl<T:ReferencesError> ReferencesError for Rc<T> {
fn references_error(&self) -> bool {
(&*self).references_error()
}
}
impl<'tcx> ReferencesError for TraitPredicate<'tcx> {
fn references_error(&self) -> bool {
self.trait_ref.references_error()
}
}
impl<'tcx> ReferencesError for ProjectionPredicate<'tcx> {
fn references_error(&self) -> bool {
self.projection_ty.trait_ref.references_error() || self.ty.references_error()
}
}
impl<'tcx> ReferencesError for TraitRef<'tcx> {
fn references_error(&self) -> bool {
self.input_types().iter().any(|t| t.references_error())
}
}
impl<'tcx> ReferencesError for Ty<'tcx> {
fn references_error(&self) -> bool {
type_is_error(*self)
}
}
impl<'tcx> ReferencesError for Predicate<'tcx> {
fn references_error(&self) -> bool {
match *self {
Predicate::Trait(ref data) => data.references_error(),
Predicate::Equate(ref data) => data.references_error(),
Predicate::RegionOutlives(ref data) => data.references_error(),
Predicate::TypeOutlives(ref data) => data.references_error(),
Predicate::Projection(ref data) => data.references_error(),
}
}
}
impl<A,B> ReferencesError for OutlivesPredicate<A,B>
where A : ReferencesError, B : ReferencesError
{
fn references_error(&self) -> bool {
self.0.references_error() || self.1.references_error()
}
}
impl<'tcx> ReferencesError for EquatePredicate<'tcx>
{
fn references_error(&self) -> bool {
self.0.references_error() || self.1.references_error()
}
}
impl ReferencesError for Region
{
fn references_error(&self) -> bool {
false
}
}
impl<'tcx> Repr<'tcx> for ClosureTy<'tcx> {
fn repr(&self, tcx: &ctxt<'tcx>) -> String {
format!("ClosureTy({},{},{},{},{},{})",
self.unsafety,
self.onceness,
self.store,
self.bounds.repr(tcx),
self.sig.repr(tcx),
self.abi)
}
}
impl<'tcx> Repr<'tcx> for UnboxedClosureUpvar<'tcx> {
fn repr(&self, tcx: &ctxt<'tcx>) -> String {
format!("UnboxedClosureUpvar({},{})",
self.def.repr(tcx),
self.ty.repr(tcx))
}
}