rust/src/librustc/middle/ty.rs

5482 lines
180 KiB
Rust

// 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)]
use back::svh::Svh;
use driver::session::Session;
use lint;
use metadata::csearch;
use middle::const_eval;
use middle::def;
use middle::dependency_format;
use middle::freevars::CaptureModeMap;
use middle::freevars;
use middle::lang_items::{FnTraitLangItem, FnMutTraitLangItem};
use middle::lang_items::{FnOnceTraitLangItem, OpaqueStructLangItem};
use middle::lang_items::{TyDescStructLangItem, TyVisitorTraitLangItem};
use middle::mem_categorization as mc;
use middle::resolve;
use middle::resolve_lifetime;
use middle::stability;
use middle::subst::{Subst, Substs, VecPerParamSpace};
use middle::subst;
use middle::ty;
use middle::typeck;
use middle::typeck::MethodCall;
use middle::ty_fold;
use middle::ty_fold::{TypeFoldable,TypeFolder};
use middle;
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::{indenter};
use util::nodemap::{NodeMap, NodeSet, DefIdMap, DefIdSet, FnvHashMap};
use std::cell::{Cell, RefCell};
use std::cmp;
use std::fmt::Show;
use std::fmt;
use std::hash::{Hash, sip, Writer};
use std::gc::Gc;
use std::iter::AdditiveIterator;
use std::mem;
use std::ops;
use std::rc::Rc;
use std::collections::{HashMap, HashSet};
use syntax::abi;
use syntax::ast::{CrateNum, DefId, FnStyle, 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::{PostExpansionMethod, is_local, lit_is_str};
use syntax::ast_util;
use syntax::attr;
use syntax::attr::AttrMetaMethods;
use syntax::codemap::Span;
use syntax::parse::token;
use syntax::parse::token::InternedString;
use syntax::{ast, ast_map};
use syntax::util::small_vector::SmallVector;
use std::collections::enum_set::{EnumSet, CLike};
pub type Disr = u64;
pub static INITIAL_DISCRIMINANT_VALUE: Disr = 0;
// Data types
#[deriving(PartialEq, Eq, Hash)]
pub struct field {
pub ident: ast::Ident,
pub mt: mt
}
#[deriving(Clone)]
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 {
MethodTraitItem(Rc<Method>),
}
impl ImplOrTraitItem {
fn id(&self) -> ImplOrTraitItemId {
match *self {
MethodTraitItem(ref method) => MethodTraitItemId(method.def_id),
}
}
pub fn def_id(&self) -> ast::DefId {
match *self {
MethodTraitItem(ref method) => method.def_id,
}
}
pub fn ident(&self) -> ast::Ident {
match *self {
MethodTraitItem(ref method) => method.ident,
}
}
pub fn container(&self) -> ImplOrTraitItemContainer {
match *self {
MethodTraitItem(ref method) => method.container,
}
}
}
#[deriving(Clone)]
pub enum ImplOrTraitItemId {
MethodTraitItemId(ast::DefId),
}
impl ImplOrTraitItemId {
pub fn def_id(&self) -> ast::DefId {
match *self {
MethodTraitItemId(def_id) => def_id,
}
}
}
#[deriving(Clone)]
pub struct Method {
pub ident: ast::Ident,
pub generics: ty::Generics,
pub fty: BareFnTy,
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 Method {
pub fn new(ident: ast::Ident,
generics: ty::Generics,
fty: BareFnTy,
explicit_self: ExplicitSelfCategory,
vis: ast::Visibility,
def_id: ast::DefId,
container: ImplOrTraitItemContainer,
provided_source: Option<ast::DefId>)
-> Method {
Method {
ident: ident,
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, PartialEq, Eq, Hash, Show)]
pub struct mt {
pub ty: t,
pub mutbl: ast::Mutability,
}
#[deriving(Clone, PartialEq, Eq, Hash, Encodable, Decodable, Show)]
pub enum TraitStore {
/// Box<Trait>
UniqTraitStore,
/// &Trait and &mut Trait
RegionTraitStore(Region, ast::Mutability),
}
#[deriving(Clone, 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(PartialEq, Eq, Hash)]
pub struct creader_cache_key {
pub cnum: CrateNum,
pub pos: uint,
pub len: uint
}
pub type creader_cache = RefCell<HashMap<creader_cache_key, t>>;
pub struct intern_key {
sty: *const sty,
}
// NB: Do not replace this with #[deriving(PartialEq)]. The automatically-derived
// implementation will not recurse through sty and you will get stack
// exhaustion.
impl cmp::PartialEq for intern_key {
fn eq(&self, other: &intern_key) -> bool {
unsafe {
*self.sty == *other.sty
}
}
fn ne(&self, other: &intern_key) -> bool {
!self.eq(other)
}
}
impl Eq for intern_key {}
impl<W:Writer> Hash<W> for intern_key {
fn hash(&self, s: &mut W) {
unsafe { (*self.sty).hash(s) }
}
}
pub enum ast_ty_to_ty_cache_entry {
atttce_unresolved, /* not resolved yet */
atttce_resolved(t) /* resolved to a type, irrespective of region */
}
#[deriving(Clone, PartialEq, Decodable, Encodable)]
pub struct ItemVariances {
pub types: VecPerParamSpace<Variance>,
pub regions: VecPerParamSpace<Variance>,
}
#[deriving(Clone, PartialEq, Decodable, Encodable, Show)]
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)]
pub enum AutoAdjustment {
AutoAddEnv(ty::TraitStore),
AutoDerefRef(AutoDerefRef)
}
#[deriving(Clone, PartialEq)]
pub enum UnsizeKind {
// [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>, uint),
UnsizeVtable(ty::ExistentialBounds,
ast::DefId, /* Trait ID */
subst::Substs /* Trait substitutions */)
}
#[deriving(Clone)]
pub struct AutoDerefRef {
pub autoderefs: uint,
pub autoref: Option<AutoRef>
}
#[deriving(Clone, PartialEq)]
pub enum AutoRef {
/// Convert from T to &T
/// The third field allows us to wrap other AutoRef adjustments.
AutoPtr(Region, ast::Mutability, Option<Box<AutoRef>>),
/// Convert [T, ..n] to [T] (or similar, depending on the kind)
AutoUnsize(UnsizeKind),
/// 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),
/// Convert from T to *T
/// Value to thin pointer
AutoUnsafe(ast::Mutability),
}
// 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))
}
}
_ => (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 {
&AutoDerefRef(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 {
&AutoDerefRef(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(cx: &ctxt, adj: &AutoAdjustment) -> Option<t> {
fn type_of_autoref(cx: &ctxt, autoref: &AutoRef) -> Option<t> {
match autoref {
&AutoUnsize(ref k) => match k {
&UnsizeVtable(bounds, def_id, ref substs) => {
Some(mk_trait(cx, def_id, substs.clone(), bounds))
}
_ => None
},
&AutoUnsizeUniq(ref k) => match k {
&UnsizeVtable(bounds, def_id, ref substs) => {
Some(mk_uniq(cx, mk_trait(cx, def_id, substs.clone(), bounds)))
}
_ => None
},
&AutoPtr(r, m, Some(box ref autoref)) => {
match type_of_autoref(cx, autoref) {
Some(t) => Some(mk_rptr(cx, r, mt {mutbl: m, ty: t})),
None => None
}
}
_ => None
}
}
match adj {
&AutoDerefRef(AutoDerefRef{autoref: Some(ref autoref), ..}) => {
type_of_autoref(cx, autoref)
}
_ => None
}
}
/// A restriction that certain types must be the same size. The use of
/// `transmute` gives rise to these restrictions.
pub struct TransmuteRestriction {
/// The span from whence the restriction comes.
pub span: Span,
/// The type being transmuted from.
pub from: t,
/// The type being transmuted to.
pub to: t,
/// NodeIf of the transmute intrinsic.
pub id: ast::NodeId,
}
/// 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 {
/// Specifically use a speedy hash algorithm for this hash map, it's used
/// quite often.
pub interner: RefCell<FnvHashMap<intern_key, Box<t_box_>>>,
pub next_id: Cell<uint>,
pub sess: Session,
pub def_map: resolve::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: node_type_table,
/// 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>>,
/// Maps from a trait item to the trait item "descriptor"
pub impl_or_trait_items: RefCell<DefIdMap<ImplOrTraitItem>>,
/// 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>>>>,
pub impl_trait_cache: RefCell<DefIdMap<Option<Rc<ty::TraitRef>>>>,
pub trait_refs: RefCell<NodeMap<Rc<TraitRef>>>,
pub trait_defs: RefCell<DefIdMap<Rc<TraitDef>>>,
pub map: ast_map::Map,
pub intrinsic_defs: RefCell<DefIdMap<t>>,
pub freevars: RefCell<freevars::freevar_map>,
pub tcache: type_cache,
pub rcache: creader_cache,
pub short_names_cache: RefCell<HashMap<t, String>>,
pub needs_unwind_cleanup_cache: RefCell<HashMap<t, bool>>,
pub tc_cache: RefCell<HashMap<uint, TypeContents>>,
pub ast_ty_to_ty_cache: RefCell<NodeMap<ast_ty_to_ty_cache_entry>>,
pub enum_var_cache: RefCell<DefIdMap<Rc<Vec<Rc<VariantInfo>>>>>,
pub ty_param_defs: RefCell<NodeMap<TypeParameterDef>>,
pub adjustments: RefCell<NodeMap<AutoAdjustment>>,
pub normalized_cache: RefCell<HashMap<t, t>>,
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 superstructs: RefCell<DefIdMap<Option<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<RefCell<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>,
/// vtable resolution information for impl declarations
pub impl_vtables: typeck::impl_vtable_map,
/// 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<Option<Gc<ast::Expr>>>>,
pub extern_const_variants: RefCell<DefIdMap<Option<Gc<ast::Expr>>>>,
pub method_map: typeck::MethodMap,
pub vtable_map: typeck::vtable_map,
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>>,
pub node_lint_levels: RefCell<HashMap<(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>>,
/// 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>,
}
pub enum tbox_flag {
has_params = 1,
has_self = 2,
needs_infer = 4,
has_regions = 8,
has_ty_err = 16,
has_ty_bot = 32,
// a meta-pub flag: subst may be required if the type has parameters, a self
// type, or references bound regions
needs_subst = 1 | 2 | 8
}
pub type t_box = &'static t_box_;
#[deriving(Show)]
pub struct t_box_ {
pub sty: sty,
pub id: uint,
pub flags: uint,
}
// To reduce refcounting cost, we're representing types as unsafe pointers
// throughout the compiler. These are simply casted t_box values. Use ty::get
// to cast them back to a box. (Without the cast, compiler performance suffers
// ~15%.) This does mean that a t value relies on the ctxt to keep its box
// alive, and using ty::get is unsafe when the ctxt is no longer alive.
enum t_opaque {}
#[allow(raw_pointer_deriving)]
#[deriving(Clone, PartialEq, Eq, Hash)]
pub struct t { inner: *const t_opaque }
impl fmt::Show for t {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "{}", get(*self))
}
}
pub fn get(t: t) -> t_box {
unsafe {
let t2: t_box = mem::transmute(t);
t2
}
}
pub fn tbox_has_flag(tb: t_box, flag: tbox_flag) -> bool {
(tb.flags & (flag as uint)) != 0u
}
pub fn type_has_params(t: t) -> bool {
tbox_has_flag(get(t), has_params)
}
pub fn type_has_self(t: t) -> bool { tbox_has_flag(get(t), has_self) }
pub fn type_needs_infer(t: t) -> bool {
tbox_has_flag(get(t), needs_infer)
}
pub fn type_id(t: t) -> uint { get(t).id }
#[deriving(Clone, PartialEq, Eq, Hash, Show)]
pub struct BareFnTy {
pub fn_style: ast::FnStyle,
pub abi: abi::Abi,
pub sig: FnSig,
}
#[deriving(Clone, PartialEq, Eq, Hash, Show)]
pub struct ClosureTy {
pub fn_style: ast::FnStyle,
pub onceness: ast::Onceness,
pub store: TraitStore,
pub bounds: ExistentialBounds,
pub sig: FnSig,
pub abi: abi::Abi,
}
/**
* Signature of a function type, which I have arbitrarily
* decided to use to refer to the input/output types.
*
* - `binder_id` is the node id where this fn type appeared;
* it is used to identify all the bound regions appearing
* in the input/output types that are bound by this fn type
* (vs some enclosing or enclosed fn type)
* - `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 {
pub binder_id: ast::NodeId,
pub inputs: Vec<t>,
pub output: t,
pub variadic: bool
}
#[deriving(Clone, PartialEq, Eq, Hash, Show)]
pub struct ParamTy {
pub space: subst::ParamSpace,
pub idx: uint,
pub def_id: DefId
}
/// Representation of regions:
#[deriving(Clone, PartialEq, Eq, Hash, Encodable, Decodable, Show)]
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*/ uint,
ast::Name),
// Region bound in a function scope, which will be substituted when the
// function is called. The first argument must be the `binder_id` of
// some enclosing function signature.
ReLateBound(/* binder_id */ ast::NodeId, 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(NodeId),
/// 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, PartialEq, Eq, Hash)]
pub struct UpvarId {
pub var_id: ast::NodeId,
pub closure_expr_id: ast::NodeId,
}
#[deriving(Clone, PartialEq, Eq, Hash, Show, Encodable, Decodable)]
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, Encodable, Decodable)]
pub struct UpvarBorrow {
pub kind: BorrowKind,
pub region: ty::Region,
}
pub type UpvarBorrowMap = HashMap<UpvarId, UpvarBorrow>;
impl Region {
pub fn is_bound(&self) -> bool {
match self {
&ty::ReEarlyBound(..) => true,
&ty::ReLateBound(..) => true,
_ => false
}
}
}
#[deriving(Clone, PartialEq, PartialOrd, Eq, Ord, Hash, Encodable, Decodable, Show)]
pub struct FreeRegion {
pub scope_id: NodeId,
pub bound_region: BoundRegion
}
#[deriving(Clone, PartialEq, PartialOrd, Eq, Ord, Hash, Encodable, Decodable, Show)]
pub enum BoundRegion {
/// An anonymous region parameter for a given fn (&T)
BrAnon(uint),
/// 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(uint),
}
mod primitives {
use super::t_box_;
use syntax::ast;
macro_rules! def_prim_ty(
($name:ident, $sty:expr, $id:expr) => (
pub static $name: t_box_ = t_box_ {
sty: $sty,
id: $id,
flags: 0,
};
)
)
def_prim_ty!(TY_NIL, super::ty_nil, 0)
def_prim_ty!(TY_BOOL, super::ty_bool, 1)
def_prim_ty!(TY_CHAR, super::ty_char, 2)
def_prim_ty!(TY_INT, super::ty_int(ast::TyI), 3)
def_prim_ty!(TY_I8, super::ty_int(ast::TyI8), 4)
def_prim_ty!(TY_I16, super::ty_int(ast::TyI16), 5)
def_prim_ty!(TY_I32, super::ty_int(ast::TyI32), 6)
def_prim_ty!(TY_I64, super::ty_int(ast::TyI64), 7)
def_prim_ty!(TY_UINT, super::ty_uint(ast::TyU), 8)
def_prim_ty!(TY_U8, super::ty_uint(ast::TyU8), 9)
def_prim_ty!(TY_U16, super::ty_uint(ast::TyU16), 10)
def_prim_ty!(TY_U32, super::ty_uint(ast::TyU32), 11)
def_prim_ty!(TY_U64, super::ty_uint(ast::TyU64), 12)
def_prim_ty!(TY_F32, super::ty_float(ast::TyF32), 14)
def_prim_ty!(TY_F64, super::ty_float(ast::TyF64), 15)
pub static TY_BOT: t_box_ = t_box_ {
sty: super::ty_bot,
id: 16,
flags: super::has_ty_bot as uint,
};
pub static TY_ERR: t_box_ = t_box_ {
sty: super::ty_err,
id: 17,
flags: super::has_ty_err as uint,
};
pub static LAST_PRIMITIVE_ID: uint = 18;
}
// 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 {
ty_nil,
ty_bot,
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 concerete 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, Substs),
ty_box(t),
ty_uniq(t),
ty_str,
ty_vec(t, Option<uint>), // Second field is length.
ty_ptr(mt),
ty_rptr(Region, mt),
ty_bare_fn(BareFnTy),
ty_closure(Box<ClosureTy>),
ty_trait(Box<TyTrait>),
ty_struct(DefId, Substs),
ty_unboxed_closure(DefId, Region),
ty_tup(Vec<t>),
ty_param(ParamTy), // type parameter
ty_open(t), // 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 {
pub def_id: DefId,
pub substs: Substs,
pub bounds: ExistentialBounds
}
#[deriving(PartialEq, Eq, Hash, Show)]
pub struct TraitRef {
pub def_id: DefId,
pub substs: Substs,
}
#[deriving(Clone, PartialEq)]
pub enum IntVarValue {
IntType(ast::IntTy),
UintType(ast::UintTy),
}
#[deriving(Clone, Show)]
pub enum terr_vstore_kind {
terr_vec,
terr_str,
terr_fn,
terr_trait
}
#[deriving(Clone, Show)]
pub struct expected_found<T> {
pub expected: T,
pub found: T
}
// Data structures used in type unification
#[deriving(Clone, Show)]
pub enum type_err {
terr_mismatch,
terr_fn_style_mismatch(expected_found<FnStyle>),
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_ty_param_size(expected_found<uint>),
terr_record_size(expected_found<uint>),
terr_record_mutability,
terr_record_fields(expected_found<Ident>),
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<t>),
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>)
}
/// 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 {
pub opt_region_bound: Option<ty::Region>,
pub builtin_bounds: BuiltinBounds,
pub trait_bounds: Vec<Rc<TraitRef>>
}
/// 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.
#[deriving(PartialEq, Eq, Hash, Clone, Show)]
pub struct ExistentialBounds {
pub region_bound: ty::Region,
pub builtin_bounds: BuiltinBounds
}
pub type BuiltinBounds = EnumSet<BuiltinBound>;
#[deriving(Clone, Encodable, PartialEq, Eq, Decodable, Hash, Show)]
#[repr(uint)]
pub enum BuiltinBound {
BoundSend,
BoundSized,
BoundCopy,
BoundSync,
}
pub fn empty_builtin_bounds() -> BuiltinBounds {
EnumSet::empty()
}
pub fn all_builtin_bounds() -> BuiltinBounds {
let mut set = EnumSet::empty();
set.add(BoundSend);
set.add(BoundSized);
set.add(BoundSync);
set
}
pub fn region_existential_bound(r: ty::Region) -> ExistentialBounds {
/*!
* An existential bound that does not implement any traits.
*/
ty::ExistentialBounds { region_bound: r,
builtin_bounds: empty_builtin_bounds() }
}
impl CLike for BuiltinBound {
fn to_uint(&self) -> uint {
*self as uint
}
fn from_uint(v: uint) -> BuiltinBound {
unsafe { mem::transmute(v) }
}
}
#[deriving(Clone, PartialEq, Eq, Hash)]
pub struct TyVid {
pub index: uint
}
#[deriving(Clone, PartialEq, Eq, Hash)]
pub struct IntVid {
pub index: uint
}
#[deriving(Clone, PartialEq, Eq, Hash)]
pub struct FloatVid {
pub index: uint
}
#[deriving(Clone, PartialEq, Eq, Encodable, Decodable, Hash)]
pub struct RegionVid {
pub index: uint
}
#[deriving(Clone, PartialEq, Eq, Hash)]
pub enum InferTy {
TyVar(TyVid),
IntVar(IntVid),
FloatVar(FloatVid)
}
#[deriving(Clone, Encodable, Decodable, Eq, Hash, Show)]
pub enum InferRegion {
ReVar(RegionVid),
ReSkolemized(uint, 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, "<generic #{}>", self.index)
}
}
impl fmt::Show for IntVid {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "<generic integer #{}>", self.index)
}
}
impl fmt::Show for FloatVid {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "<generic float #{}>", self.index)
}
}
impl fmt::Show for RegionVid {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "'<generic lifetime #{}>", self.index)
}
}
impl fmt::Show for FnSig {
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),
}
}
}
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 {
pub ident: ast::Ident,
pub def_id: ast::DefId,
pub space: subst::ParamSpace,
pub index: uint,
pub bounds: ParamBounds,
pub default: Option<ty::t>,
}
#[deriving(Encodable, Decodable, Clone, Show)]
pub struct RegionParameterDef {
pub name: ast::Name,
pub def_id: ast::DefId,
pub space: subst::ParamSpace,
pub index: uint,
pub bounds: Vec<ty::Region>,
}
/// Information about the type/lifetime parameters associated with an
/// item or method. Analogous to ast::Generics.
#[deriving(Clone, Show)]
pub struct Generics {
pub types: VecPerParamSpace<TypeParameterDef>,
pub regions: VecPerParamSpace<RegionParameterDef>,
}
impl Generics {
pub fn empty() -> Generics {
Generics { types: VecPerParamSpace::empty(),
regions: 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)
}
}
/// 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.
pub struct ParameterEnvironment {
/// 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 affect on regions.
pub free_substs: Substs,
/// Bounds on the various type parameters
pub bounds: VecPerParamSpace<ParamBounds>,
/// 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,
}
impl ParameterEnvironment {
pub fn for_item(cx: &ctxt, id: NodeId) -> ParameterEnvironment {
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)
}
}
}
}
}
Some(ast_map::NodeTraitItem(trait_method)) => {
match *trait_method {
ast::RequiredMethod(ref required) => {
cx.sess.span_bug(required.span,
"ParameterEnvironment::from_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)
}
}
}
}
}
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::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")
}
}
}
_ => {
cx.sess.bug(format!("ParameterEnvironment::from_item(): \
`{}` is not an item",
cx.map.node_to_string(id)).as_slice())
}
}
}
}
/// A polytype.
///
/// - `generics`: the set of type parameters and their bounds
/// - `ty`: the base types, which may reference the parameters defined
/// in `generics`
#[deriving(Clone, Show)]
pub struct Polytype {
pub generics: Generics,
pub ty: t
}
/// As `Polytype` but for a trait ref.
pub struct TraitDef {
pub generics: Generics,
pub bounds: ParamBounds,
pub trait_ref: Rc<ty::TraitRef>,
}
/// Records the substitutions used to translate the polytype for an
/// item into the monotype of an item reference.
#[deriving(Clone)]
pub struct ItemSubsts {
pub substs: Substs,
}
pub type type_cache = RefCell<DefIdMap<Polytype>>;
pub type node_type_table = RefCell<HashMap<uint,t>>;
/// Records information about each unboxed closure.
pub struct UnboxedClosure {
/// The type of the unboxed closure.
pub closure_type: ClosureTy,
/// The kind of unboxed closure this is.
pub kind: UnboxedClosureKind,
}
#[deriving(PartialEq, Eq)]
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.as_slice()),
}
}
}
pub fn mk_ctxt(s: Session,
dm: resolve::DefMap,
named_region_map: resolve_lifetime::NamedRegionMap,
map: ast_map::Map,
freevars: freevars::freevar_map,
capture_modes: freevars::CaptureModeMap,
region_maps: middle::region::RegionMaps,
lang_items: middle::lang_items::LanguageItems,
stability: stability::Index)
-> ctxt {
ctxt {
named_region_map: named_region_map,
item_variance_map: RefCell::new(DefIdMap::new()),
variance_computed: Cell::new(false),
interner: RefCell::new(FnvHashMap::new()),
next_id: Cell::new(primitives::LAST_PRIMITIVE_ID),
sess: s,
def_map: dm,
region_maps: region_maps,
node_types: RefCell::new(HashMap::new()),
item_substs: RefCell::new(NodeMap::new()),
trait_refs: RefCell::new(NodeMap::new()),
trait_defs: RefCell::new(DefIdMap::new()),
map: map,
intrinsic_defs: RefCell::new(DefIdMap::new()),
freevars: RefCell::new(freevars),
tcache: RefCell::new(DefIdMap::new()),
rcache: RefCell::new(HashMap::new()),
short_names_cache: RefCell::new(HashMap::new()),
needs_unwind_cleanup_cache: RefCell::new(HashMap::new()),
tc_cache: RefCell::new(HashMap::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(HashMap::new()),
lang_items: lang_items,
provided_method_sources: RefCell::new(DefIdMap::new()),
superstructs: 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()),
impl_vtables: RefCell::new(DefIdMap::new()),
populated_external_types: RefCell::new(DefIdSet::new()),
populated_external_traits: RefCell::new(DefIdSet::new()),
upvar_borrow_map: RefCell::new(HashMap::new()),
extern_const_statics: RefCell::new(DefIdMap::new()),
extern_const_variants: RefCell::new(DefIdMap::new()),
method_map: RefCell::new(FnvHashMap::new()),
vtable_map: RefCell::new(FnvHashMap::new()),
dependency_formats: RefCell::new(HashMap::new()),
unboxed_closures: RefCell::new(DefIdMap::new()),
node_lint_levels: RefCell::new(HashMap::new()),
transmute_restrictions: RefCell::new(Vec::new()),
stability: RefCell::new(stability),
capture_modes: RefCell::new(capture_modes),
}
}
// Type constructors
// 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 t above).
pub fn mk_t(cx: &ctxt, st: sty) -> t {
// Check for primitive types.
match st {
ty_nil => return mk_nil(),
ty_err => return mk_err(),
ty_bool => return mk_bool(),
ty_int(i) => return mk_mach_int(i),
ty_uint(u) => return mk_mach_uint(u),
ty_float(f) => return mk_mach_float(f),
ty_char => return mk_char(),
ty_bot => return mk_bot(),
_ => {}
};
let key = intern_key { sty: &st };
match cx.interner.borrow().find(&key) {
Some(t) => unsafe { return mem::transmute(&t.sty); },
_ => ()
}
let mut flags = 0u;
fn rflags(r: Region) -> uint {
(has_regions as uint) | {
match r {
ty::ReInfer(_) => needs_infer as uint,
_ => 0u
}
}
}
fn sflags(substs: &Substs) -> uint {
let mut f = 0u;
let mut i = substs.types.iter();
for tt in i {
f |= get(*tt).flags;
}
match substs.regions {
subst::ErasedRegions => {}
subst::NonerasedRegions(ref regions) => {
for r in regions.iter() {
f |= rflags(*r)
}
}
}
return f;
}
fn flags_for_bounds(bounds: &ExistentialBounds) -> uint {
rflags(bounds.region_bound)
}
match &st {
&ty_nil | &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_bot => flags |= has_ty_bot as uint,
&ty_err => flags |= has_ty_err as uint,
&ty_param(ref p) => {
if p.space == subst::SelfSpace {
flags |= has_self as uint;
} else {
flags |= has_params as uint;
}
}
&ty_unboxed_closure(_, ref region) => flags |= rflags(*region),
&ty_infer(_) => flags |= needs_infer as uint,
&ty_enum(_, ref substs) | &ty_struct(_, ref substs) => {
flags |= sflags(substs);
}
&ty_trait(box ty::TyTrait { ref substs, ref bounds, .. }) => {
flags |= sflags(substs);
flags |= flags_for_bounds(bounds);
}
&ty_box(tt) | &ty_uniq(tt) | &ty_vec(tt, _) | &ty_open(tt) => {
flags |= get(tt).flags
}
&ty_ptr(ref m) => {
flags |= get(m.ty).flags;
}
&ty_rptr(r, ref m) => {
flags |= rflags(r);
flags |= get(m.ty).flags;
}
&ty_tup(ref ts) => for tt in ts.iter() { flags |= get(*tt).flags; },
&ty_bare_fn(ref f) => {
for a in f.sig.inputs.iter() { flags |= get(*a).flags; }
flags |= get(f.sig.output).flags;
// T -> _|_ is *not* _|_ !
flags &= !(has_ty_bot as uint);
}
&ty_closure(ref f) => {
match f.store {
RegionTraitStore(r, _) => {
flags |= rflags(r);
}
_ => {}
}
for a in f.sig.inputs.iter() { flags |= get(*a).flags; }
flags |= get(f.sig.output).flags;
// T -> _|_ is *not* _|_ !
flags &= !(has_ty_bot as uint);
flags |= flags_for_bounds(&f.bounds);
}
}
let t = box t_box_ {
sty: st,
id: cx.next_id.get(),
flags: flags,
};
let sty_ptr = &t.sty as *const sty;
let key = intern_key {
sty: sty_ptr,
};
cx.interner.borrow_mut().insert(key, t);
cx.next_id.set(cx.next_id.get() + 1);
unsafe {
mem::transmute::<*const sty, t>(sty_ptr)
}
}
#[inline]
pub fn mk_prim_t(primitive: &'static t_box_) -> t {
unsafe {
mem::transmute::<&'static t_box_, t>(primitive)
}
}
#[inline]
pub fn mk_nil() -> t { mk_prim_t(&primitives::TY_NIL) }
#[inline]
pub fn mk_err() -> t { mk_prim_t(&primitives::TY_ERR) }
#[inline]
pub fn mk_bot() -> t { mk_prim_t(&primitives::TY_BOT) }
#[inline]
pub fn mk_bool() -> t { mk_prim_t(&primitives::TY_BOOL) }
#[inline]
pub fn mk_int() -> t { mk_prim_t(&primitives::TY_INT) }
#[inline]
pub fn mk_i8() -> t { mk_prim_t(&primitives::TY_I8) }
#[inline]
pub fn mk_i16() -> t { mk_prim_t(&primitives::TY_I16) }
#[inline]
pub fn mk_i32() -> t { mk_prim_t(&primitives::TY_I32) }
#[inline]
pub fn mk_i64() -> t { mk_prim_t(&primitives::TY_I64) }
#[inline]
pub fn mk_f32() -> t { mk_prim_t(&primitives::TY_F32) }
#[inline]
pub fn mk_f64() -> t { mk_prim_t(&primitives::TY_F64) }
#[inline]
pub fn mk_uint() -> t { mk_prim_t(&primitives::TY_UINT) }
#[inline]
pub fn mk_u8() -> t { mk_prim_t(&primitives::TY_U8) }
#[inline]
pub fn mk_u16() -> t { mk_prim_t(&primitives::TY_U16) }
#[inline]
pub fn mk_u32() -> t { mk_prim_t(&primitives::TY_U32) }
#[inline]
pub fn mk_u64() -> t { mk_prim_t(&primitives::TY_U64) }
pub fn mk_mach_int(tm: ast::IntTy) -> t {
match tm {
ast::TyI => mk_int(),
ast::TyI8 => mk_i8(),
ast::TyI16 => mk_i16(),
ast::TyI32 => mk_i32(),
ast::TyI64 => mk_i64(),
}
}
pub fn mk_mach_uint(tm: ast::UintTy) -> t {
match tm {
ast::TyU => mk_uint(),
ast::TyU8 => mk_u8(),
ast::TyU16 => mk_u16(),
ast::TyU32 => mk_u32(),
ast::TyU64 => mk_u64(),
}
}
pub fn mk_mach_float(tm: ast::FloatTy) -> t {
match tm {
ast::TyF32 => mk_f32(),
ast::TyF64 => mk_f64(),
}
}
#[inline]
pub fn mk_char() -> t { mk_prim_t(&primitives::TY_CHAR) }
pub fn mk_str(cx: &ctxt) -> t {
mk_t(cx, ty_str)
}
pub fn mk_str_slice(cx: &ctxt, r: Region, m: ast::Mutability) -> t {
mk_rptr(cx, r,
mt {
ty: mk_t(cx, ty_str),
mutbl: m
})
}
pub fn mk_enum(cx: &ctxt, did: ast::DefId, substs: Substs) -> t {
// take a copy of substs so that we own the vectors inside
mk_t(cx, ty_enum(did, substs))
}
pub fn mk_box(cx: &ctxt, ty: t) -> t { mk_t(cx, ty_box(ty)) }
pub fn mk_uniq(cx: &ctxt, ty: t) -> t { mk_t(cx, ty_uniq(ty)) }
pub fn mk_ptr(cx: &ctxt, tm: mt) -> t { mk_t(cx, ty_ptr(tm)) }
pub fn mk_rptr(cx: &ctxt, r: Region, tm: mt) -> t { mk_t(cx, ty_rptr(r, tm)) }
pub fn mk_mut_rptr(cx: &ctxt, r: Region, ty: t) -> t {
mk_rptr(cx, r, mt {ty: ty, mutbl: ast::MutMutable})
}
pub fn mk_imm_rptr(cx: &ctxt, r: Region, ty: t) -> t {
mk_rptr(cx, r, mt {ty: ty, mutbl: ast::MutImmutable})
}
pub fn mk_mut_ptr(cx: &ctxt, ty: t) -> t {
mk_ptr(cx, mt {ty: ty, mutbl: ast::MutMutable})
}
pub fn mk_imm_ptr(cx: &ctxt, ty: t) -> t {
mk_ptr(cx, mt {ty: ty, mutbl: ast::MutImmutable})
}
pub fn mk_nil_ptr(cx: &ctxt) -> t {
mk_ptr(cx, mt {ty: mk_nil(), mutbl: ast::MutImmutable})
}
pub fn mk_vec(cx: &ctxt, t: t, sz: Option<uint>) -> t {
mk_t(cx, ty_vec(t, sz))
}
pub fn mk_slice(cx: &ctxt, r: Region, tm: mt) -> t {
mk_rptr(cx, r,
mt {
ty: mk_vec(cx, tm.ty, None),
mutbl: tm.mutbl
})
}
pub fn mk_tup(cx: &ctxt, ts: Vec<t>) -> t { mk_t(cx, ty_tup(ts)) }
pub fn mk_closure(cx: &ctxt, fty: ClosureTy) -> t {
mk_t(cx, ty_closure(box fty))
}
pub fn mk_bare_fn(cx: &ctxt, fty: BareFnTy) -> t {
mk_t(cx, ty_bare_fn(fty))
}
pub fn mk_ctor_fn(cx: &ctxt,
binder_id: ast::NodeId,
input_tys: &[ty::t],
output: ty::t) -> t {
let input_args = input_tys.iter().map(|t| *t).collect();
mk_bare_fn(cx,
BareFnTy {
fn_style: ast::NormalFn,
abi: abi::Rust,
sig: FnSig {
binder_id: binder_id,
inputs: input_args,
output: output,
variadic: false
}
})
}
pub fn mk_trait(cx: &ctxt,
did: ast::DefId,
substs: Substs,
bounds: ExistentialBounds)
-> t {
// take a copy of substs so that we own the vectors inside
let inner = box TyTrait {
def_id: did,
substs: substs,
bounds: bounds
};
mk_t(cx, ty_trait(inner))
}
pub fn mk_struct(cx: &ctxt, struct_id: ast::DefId, substs: Substs) -> t {
// 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(cx: &ctxt, closure_id: ast::DefId, region: Region)
-> t {
mk_t(cx, ty_unboxed_closure(closure_id, region))
}
pub fn mk_var(cx: &ctxt, v: TyVid) -> t { mk_infer(cx, TyVar(v)) }
pub fn mk_int_var(cx: &ctxt, v: IntVid) -> t { mk_infer(cx, IntVar(v)) }
pub fn mk_float_var(cx: &ctxt, v: FloatVid) -> t { mk_infer(cx, FloatVar(v)) }
pub fn mk_infer(cx: &ctxt, it: InferTy) -> t { mk_t(cx, ty_infer(it)) }
pub fn mk_param(cx: &ctxt, space: subst::ParamSpace, n: uint, k: DefId) -> t {
mk_t(cx, ty_param(ParamTy { space: space, idx: n, def_id: k }))
}
pub fn mk_self_type(cx: &ctxt, did: ast::DefId) -> t {
mk_param(cx, subst::SelfSpace, 0, did)
}
pub fn mk_param_from_def(cx: &ctxt, def: &TypeParameterDef) -> t {
mk_param(cx, def.space, def.index, def.def_id)
}
pub fn mk_open(cx: &ctxt, t: t) -> t { mk_t(cx, ty_open(t)) }
pub fn walk_ty(ty: t, f: |t|) {
maybe_walk_ty(ty, |t| { f(t); true });
}
pub fn maybe_walk_ty(ty: t, f: |t| -> bool) {
if !f(ty) {
return;
}
match get(ty).sty {
ty_nil | ty_bot | ty_bool | ty_char | ty_int(_) | ty_uint(_) | ty_float(_) |
ty_str | ty_infer(_) | ty_param(_) | ty_unboxed_closure(_, _) | ty_err => {}
ty_box(ty) | 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_enum(_, ref substs) | ty_struct(_, ref substs) |
ty_trait(box TyTrait { ref substs, .. }) => {
for subty in (*substs).types.iter() {
maybe_walk_ty(*subty, |x| f(x));
}
}
ty_tup(ref ts) => { for tt in ts.iter() { maybe_walk_ty(*tt, |x| f(x)); } }
ty_bare_fn(ref ft) => {
for a in ft.sig.inputs.iter() { maybe_walk_ty(*a, |x| f(x)); }
maybe_walk_ty(ft.sig.output, f);
}
ty_closure(ref ft) => {
for a in ft.sig.inputs.iter() { maybe_walk_ty(*a, |x| f(x)); }
maybe_walk_ty(ft.sig.output, f);
}
}
}
// Folds types from the bottom up.
pub fn fold_ty(cx: &ctxt, t0: t, fldop: |t| -> t) -> t {
let mut f = ty_fold::BottomUpFolder {tcx: cx, fldop: fldop};
f.fold_ty(t0)
}
pub fn walk_regions_and_ty(cx: &ctxt, ty: t, fldr: |r: Region|, fldt: |t: t|)
-> t {
ty_fold::RegionFolder::general(cx,
|r| { fldr(r); r },
|t| { fldt(t); t }).fold_ty(ty)
}
impl ParamTy {
pub fn new(space: subst::ParamSpace,
index: uint,
def_id: ast::DefId)
-> ParamTy {
ParamTy { space: space, idx: index, def_id: def_id }
}
pub fn for_self(trait_def_id: ast::DefId) -> ParamTy {
ParamTy::new(subst::SelfSpace, 0, trait_def_id)
}
pub fn for_def(def: &TypeParameterDef) -> ParamTy {
ParamTy::new(def.space, def.index, def.def_id)
}
pub fn to_ty(self, tcx: &ty::ctxt) -> ty::t {
ty::mk_param(tcx, self.space, self.idx, self.def_id)
}
}
impl ItemSubsts {
pub fn empty() -> ItemSubsts {
ItemSubsts { substs: Substs::empty() }
}
pub fn is_noop(&self) -> bool {
self.substs.is_noop()
}
}
// Type utilities
pub fn type_is_nil(ty: t) -> bool { get(ty).sty == ty_nil }
pub fn type_is_bot(ty: t) -> bool {
(get(ty).flags & (has_ty_bot as uint)) != 0
}
pub fn type_is_error(ty: t) -> bool {
(get(ty).flags & (has_ty_err as uint)) != 0
}
pub fn type_needs_subst(ty: t) -> bool {
tbox_has_flag(get(ty), needs_subst)
}
pub fn trait_ref_contains_error(tref: &ty::TraitRef) -> bool {
tref.substs.types.any(|&t| type_is_error(t))
}
pub fn type_is_ty_var(ty: t) -> bool {
match get(ty).sty {
ty_infer(TyVar(_)) => true,
_ => false
}
}
pub fn type_is_bool(ty: t) -> bool { get(ty).sty == ty_bool }
pub fn type_is_self(ty: t) -> bool {
match get(ty).sty {
ty_param(ref p) => p.space == subst::SelfSpace,
_ => false
}
}
fn type_is_slice(ty: t) -> bool {
match get(ty).sty {
ty_rptr(_, mt) => match get(mt.ty).sty {
ty_vec(_, None) | ty_str => true,
_ => false,
},
_ => false
}
}
pub fn type_is_vec(ty: t) -> bool {
match get(ty).sty {
ty_vec(..) => true,
ty_ptr(mt{ty: t, ..}) | ty_rptr(_, mt{ty: t, ..}) |
ty_box(t) | ty_uniq(t) => match get(t).sty {
ty_vec(_, None) => true,
_ => false
},
_ => false
}
}
pub fn type_is_structural(ty: t) -> bool {
match get(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: t) -> bool {
match get(ty).sty {
ty_struct(did, _) => lookup_simd(cx, did),
_ => false
}
}
pub fn sequence_element_type(cx: &ctxt, ty: t) -> t {
match get(ty).sty {
ty_vec(ty, _) => ty,
ty_str => mk_mach_uint(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)).as_slice()),
}
}
pub fn simd_type(cx: &ctxt, ty: t) -> t {
match get(ty).sty {
ty_struct(did, ref substs) => {
let fields = lookup_struct_fields(cx, did);
lookup_field_type(cx, did, fields.get(0).id, substs)
}
_ => fail!("simd_type called on invalid type")
}
}
pub fn simd_size(cx: &ctxt, ty: t) -> uint {
match get(ty).sty {
ty_struct(did, _) => {
let fields = lookup_struct_fields(cx, did);
fields.len()
}
_ => fail!("simd_size called on invalid type")
}
}
pub fn type_is_boxed(ty: t) -> bool {
match get(ty).sty {
ty_box(_) => true,
_ => false
}
}
pub fn type_is_region_ptr(ty: t) -> bool {
match get(ty).sty {
ty_rptr(..) => true,
_ => false
}
}
pub fn type_is_unsafe_ptr(ty: t) -> bool {
match get(ty).sty {
ty_ptr(_) => return true,
_ => return false
}
}
pub fn type_is_unique(ty: t) -> bool {
match get(ty).sty {
ty_uniq(_) => match get(ty).sty {
ty_trait(..) => false,
_ => true
},
_ => false
}
}
pub fn type_is_fat_ptr(cx: &ctxt, ty: t) -> bool {
match get(ty).sty {
ty_rptr(_, mt{ty, ..}) | ty_uniq(ty) if !type_is_sized(cx, ty) => 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: t) -> bool {
match get(ty).sty {
ty_nil | ty_bool | ty_char | ty_int(_) | ty_float(_) | ty_uint(_) |
ty_infer(IntVar(_)) | ty_infer(FloatVar(_)) |
ty_bare_fn(..) | ty_ptr(_) => true,
_ => false
}
}
/// Returns true if this type is a floating point type and false otherwise.
pub fn type_is_floating_point(ty: t) -> bool {
match get(ty).sty {
ty_float(_) => true,
_ => false,
}
}
pub fn type_needs_drop(cx: &ctxt, ty: t) -> bool {
type_contents(cx, ty).needs_drop(cx)
}
// Some things don't need cleanups during unwinding because the
// task can free them all at once later. Currently only things
// that only contain scalars and shared boxes can avoid unwind
// cleanups.
pub fn type_needs_unwind_cleanup(cx: &ctxt, ty: t) -> bool {
match cx.needs_unwind_cleanup_cache.borrow().find(&ty) {
Some(&result) => return result,
None => ()
}
let mut tycache = HashSet::new();
let needs_unwind_cleanup =
type_needs_unwind_cleanup_(cx, ty, &mut tycache, false);
cx.needs_unwind_cleanup_cache.borrow_mut().insert(ty, needs_unwind_cleanup);
return needs_unwind_cleanup;
}
fn type_needs_unwind_cleanup_(cx: &ctxt, ty: t,
tycache: &mut HashSet<t>,
encountered_box: bool) -> bool {
// Prevent infinite recursion
if !tycache.insert(ty) {
return false;
}
let mut encountered_box = encountered_box;
let mut needs_unwind_cleanup = false;
maybe_walk_ty(ty, |ty| {
let old_encountered_box = encountered_box;
let result = match get(ty).sty {
ty_box(_) => {
encountered_box = true;
true
}
ty_nil | ty_bot | ty_bool | ty_int(_) | ty_uint(_) | ty_float(_) |
ty_tup(_) | ty_ptr(_) => {
true
}
ty_enum(did, ref substs) => {
for v in (*enum_variants(cx, did)).iter() {
for aty in v.args.iter() {
let t = aty.subst(cx, substs);
needs_unwind_cleanup |=
type_needs_unwind_cleanup_(cx, t, tycache,
encountered_box);
}
}
!needs_unwind_cleanup
}
ty_uniq(_) => {
// Once we're inside a box, the annihilator will find
// it and destroy it.
if !encountered_box {
needs_unwind_cleanup = true;
false
} else {
true
}
}
_ => {
needs_unwind_cleanup = true;
false
}
};
encountered_box = old_encountered_box;
result
});
return needs_unwind_cleanup;
}
/**
* 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.
*/
pub struct TypeContents {
pub bits: u64
}
macro_rules! def_type_content_sets(
(mod $mname:ident { $($name:ident = $bits:expr),+ }) => {
mod $mname {
use middle::ty::TypeContents;
$(pub static $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,
// 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,
OwnsAffine = 0b0000_0000__0000_1000__0000,
OwnsAll = 0b0000_0000__1111_1111__0000,
// Things that are reachable by the value in any way (fourth nibble):
ReachesNonsendAnnot = 0b0000_0001__0000_0000__0000,
ReachesBorrowed = 0b0000_0010__0000_0000__0000,
// ReachesManaged /* see [1] below */ = 0b0000_0100__0000_0000__0000,
ReachesMutable = 0b0000_1000__0000_0000__0000,
ReachesNoSync = 0b0001_0000__0000_0000__0000,
ReachesFfiUnsafe = 0b0010_0000__0000_0000__0000,
ReachesAll = 0b0011_1111__0000_0000__0000,
// Things that cause values to *move* rather than *copy*
Moves = 0b0000_0000__0000_1011__0000,
// Things that mean drop glue is necessary
NeedsDrop = 0b0000_0000__0000_0111__0000,
// Things that prevent values from being sent
//
// Note: For checking whether something is sendable, it'd
// be sufficient to have ReachesManaged. However, we include
// both ReachesManaged and OwnsManaged so that when
// a parameter has a bound T:Send, we are able to deduce
// that it neither reaches nor owns a managed pointer.
Nonsendable = 0b0000_0111__0000_0100__0000,
// Things that prevent values from being considered sized
Nonsized = 0b0000_0000__0000_0000__0001,
// Things that prevent values from being sync
Nonsync = 0b0001_0000__0000_0000__0000,
// Things that make values considered not POD (would be same
// as `Moves`, but for the fact that managed data `@` is
// not considered POD)
Noncopy = 0b0000_0000__0000_1111__0000,
// 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 meets_builtin_bound(&self, cx: &ctxt, bb: BuiltinBound) -> bool {
match bb {
BoundSend => self.is_sendable(cx),
BoundSized => self.is_sized(cx),
BoundCopy => self.is_copy(cx),
BoundSync => self.is_sync(cx),
}
}
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 is_sendable(&self, _: &ctxt) -> bool {
!self.intersects(TC::Nonsendable)
}
pub fn is_sync(&self, _: &ctxt) -> bool {
!self.intersects(TC::Nonsync)
}
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 is_copy(&self, _: &ctxt) -> bool {
!self.intersects(TC::Noncopy)
}
pub fn interior_unsafe(&self) -> bool {
self.intersects(TC::InteriorUnsafe)
}
pub fn interior_unsized(&self) -> bool {
self.intersects(TC::InteriorUnsized)
}
pub fn moves_by_default(&self, _: &ctxt) -> bool {
self.intersects(TC::Moves)
}
pub fn needs_drop(&self, _: &ctxt) -> bool {
self.intersects(TC::NeedsDrop)
}
pub fn owned_pointer(&self) -> TypeContents {
/*!
* Includes only those bits that still apply
* when indirected through a `Box` pointer
*/
TC::OwnsOwned | (
*self & (TC::OwnsAll | TC::ReachesAll))
}
pub fn reference(&self, bits: TypeContents) -> TypeContents {
/*!
* Includes only those bits that still apply
* when indirected through a reference (`&`)
*/
bits | (
*self & TC::ReachesAll)
}
pub fn managed_pointer(&self) -> TypeContents {
/*!
* Includes only those bits that still apply
* when indirected through a managed pointer (`@`)
*/
TC::Managed | (
*self & TC::ReachesAll)
}
pub fn unsafe_pointer(&self) -> TypeContents {
/*!
* Includes only those bits that still apply
* when indirected through an unsafe pointer (`*`)
*/
*self & TC::ReachesAll
}
pub fn union<T>(v: &[T], f: |&T| -> TypeContents) -> TypeContents {
v.iter().fold(TC::None, |tc, t| tc | f(t))
}
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({:t})", self.bits)
}
}
pub fn type_is_sendable(cx: &ctxt, t: ty::t) -> bool {
type_contents(cx, t).is_sendable(cx)
}
pub fn type_interior_is_unsafe(cx: &ctxt, t: ty::t) -> bool {
type_contents(cx, t).interior_unsafe()
}
pub fn type_contents(cx: &ctxt, ty: t) -> TypeContents {
let ty_id = type_id(ty);
match cx.tc_cache.borrow().find(&ty_id) {
Some(tc) => { return *tc; }
None => {}
}
let mut cache = HashMap::new();
let result = tc_ty(cx, ty, &mut cache);
cx.tc_cache.borrow_mut().insert(ty_id, result);
return result;
fn tc_ty(cx: &ctxt,
ty: t,
cache: &mut HashMap<uint, 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.
let ty_id = type_id(ty);
match cache.find(&ty_id) {
Some(tc) => { return *tc; }
None => {}
}
match cx.tc_cache.borrow().find(&ty_id) { // Must check both caches!
Some(tc) => { return *tc; }
None => {}
}
cache.insert(ty_id, TC::None);
let result = match get(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_nil | ty_bot | ty_bool | ty_int(_) | ty_uint(_) | ty_float(_) |
ty_bare_fn(_) | ty::ty_char => {
TC::None
}
ty_closure(ref c) => {
closure_contents(cx, &**c) | TC::ReachesFfiUnsafe
}
ty_box(typ) => {
tc_ty(cx, typ, cache).managed_pointer() | TC::ReachesFfiUnsafe
}
ty_uniq(typ) => {
TC::ReachesFfiUnsafe | match get(typ).sty {
ty_str => TC::OwnsOwned,
_ => tc_ty(cx, typ, cache).owned_pointer(),
}
}
ty_trait(box ty::TyTrait { bounds, .. }) => {
object_contents(cx, bounds) | TC::ReachesFfiUnsafe
}
ty_ptr(ref mt) => {
tc_ty(cx, mt.ty, cache).unsafe_pointer()
}
ty_rptr(r, ref mt) => {
TC::ReachesFfiUnsafe | match get(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(t, Some(_)) => {
tc_ty(cx, t, cache)
}
ty_vec(t, None) => {
tc_ty(cx, t, cache) | TC::Nonsized
}
ty_str => TC::Nonsized,
ty_struct(did, ref substs) => {
let flds = struct_fields(cx, did, substs);
let mut res =
TypeContents::union(flds.as_slice(),
|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) => {
// FIXME(#14449): `borrowed_contents` below assumes `&mut`
// unboxed closure.
let upvars = unboxed_closure_upvars(cx, did);
TypeContents::union(upvars.as_slice(),
|f| tc_ty(cx, f.ty, cache)) |
borrowed_contents(r, MutMutable)
}
ty_tup(ref tys) => {
TypeContents::union(tys.as_slice(),
|ty| tc_ty(cx, *ty, cache))
}
ty_enum(did, ref substs) => {
let variants = substd_enum_variants(cx, did, substs);
let mut res =
TypeContents::union(variants.as_slice(), |variant| {
TypeContents::union(variant.args.as_slice(),
|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.as_slice().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.get(0).args.len() == 0 {
data_idx = 1;
}
if variants.get(data_idx).args.len() == 1 {
match get(*variants.get(data_idx).args.get(0)).sty {
ty_bare_fn(..) => { res = res - TC::ReachesFfiUnsafe; }
_ => { }
}
}
}
}
}
}
apply_lang_items(cx, did, res)
}
ty_param(p) => {
// We only ever ask for the kind of types that are defined in
// the current crate; therefore, the only type parameters that
// could be in scope are those defined in the current crate.
// If this assertion failures, it is likely because of a
// failure in the cross-crate inlining code to translate a
// def-id.
assert_eq!(p.def_id.krate, ast::LOCAL_CRATE);
let ty_param_defs = cx.ty_param_defs.borrow();
let tp_def = ty_param_defs.get(&p.def_id.node);
kind_bounds_to_contents(
cx,
tp_def.bounds.builtin_bounds,
tp_def.bounds.trait_bounds.as_slice())
}
ty_infer(_) => {
// This occurs during coherence, but shouldn't occur at other
// times.
TC::All
}
ty_open(t) => {
let result = tc_ty(cx, t, cache);
assert!(!result.is_sized(cx))
result.unsafe_pointer() | TC::Nonsized
}
ty_err => {
cx.sess.bug("asked to compute contents of error type");
}
};
cache.insert(ty_id, result);
return result;
}
fn tc_mt(cx: &ctxt,
mt: mt,
cache: &mut HashMap<uint, 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.no_send_bound() {
tc | TC::ReachesNonsendAnnot
} else if Some(did) == cx.lang_items.managed_bound() {
tc | TC::Managed
} else if Some(did) == cx.lang_items.no_copy_bound() {
tc | TC::OwnsAffine
} else if Some(did) == cx.lang_items.no_share_bound() {
tc | TC::ReachesNoSync
} else if Some(did) == cx.lang_items.unsafe_type() {
// FIXME(#13231): This shouldn't be needed after
// opt-in built-in bounds are implemented.
(tc | TC::InteriorUnsafe) - TC::Nonsync
} else {
tc
}
}
fn borrowed_contents(region: ty::Region,
mutbl: ast::Mutability)
-> TypeContents {
/*!
* Type contents due to containing a reference
* with the region `region` and borrow kind `bk`
*/
let b = match mutbl {
ast::MutMutable => TC::ReachesMutable | TC::OwnsAffine,
ast::MutImmutable => TC::None,
};
b | (TC::ReachesBorrowed).when(region != ty::ReStatic)
}
fn closure_contents(cx: &ctxt, cty: &ClosureTy) -> TypeContents {
// Closure contents are just like trait contents, but with potentially
// even more stuff.
let st = object_contents(cx, cty.bounds);
let st = match cty.store {
UniqTraitStore => {
st.owned_pointer()
}
RegionTraitStore(r, mutbl) => {
st.reference(borrowed_contents(r, mutbl))
}
};
// This also prohibits "@once fn" from being copied, which allows it to
// be called. Neither way really makes much sense.
let ot = match cty.onceness {
ast::Once => TC::OwnsAffine,
ast::Many => TC::None,
};
st | ot
}
fn object_contents(cx: &ctxt,
bounds: ExistentialBounds)
-> TypeContents {
// These are the type contents of the (opaque) interior
kind_bounds_to_contents(cx, bounds.builtin_bounds, [])
}
fn kind_bounds_to_contents(cx: &ctxt,
bounds: BuiltinBounds,
traits: &[Rc<TraitRef>])
-> TypeContents {
let _i = indenter();
let mut tc = TC::All;
each_inherited_builtin_bound(cx, bounds, traits, |bound| {
tc = tc - match bound {
BoundSend => TC::Nonsendable,
BoundSized => TC::Nonsized,
BoundCopy => TC::Noncopy,
BoundSync => TC::Nonsync,
};
});
return tc;
// Iterates over all builtin bounds on the type parameter def, including
// those inherited from traits with builtin-kind-supertraits.
fn each_inherited_builtin_bound(cx: &ctxt,
bounds: BuiltinBounds,
traits: &[Rc<TraitRef>],
f: |BuiltinBound|) {
for bound in bounds.iter() {
f(bound);
}
each_bound_trait_and_supertraits(cx, traits, |trait_ref| {
let trait_def = lookup_trait_def(cx, trait_ref.def_id);
for bound in trait_def.bounds.builtin_bounds.iter() {
f(bound);
}
true
});
}
}
}
pub fn type_moves_by_default(cx: &ctxt, ty: t) -> bool {
type_contents(cx, ty).moves_by_default(cx)
}
pub fn is_ffi_safe(cx: &ctxt, ty: t) -> 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(cx: &ctxt, r_ty: t) -> bool {
fn type_requires(cx: &ctxt, seen: &mut Vec<DefId>,
r_ty: t, ty: t) -> bool {
debug!("type_requires({}, {})?",
::util::ppaux::ty_to_string(cx, r_ty),
::util::ppaux::ty_to_string(cx, ty));
let r = {
get(r_ty).sty == get(ty).sty ||
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(cx: &ctxt, seen: &mut Vec<DefId>,
r_ty: t, ty: t) -> bool {
debug!("subtypes_require({}, {})?",
::util::ppaux::ty_to_string(cx, r_ty),
::util::ppaux::ty_to_string(cx, ty));
let r = match get(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_nil |
ty_bot |
ty_bool |
ty_char |
ty_int(_) |
ty_uint(_) |
ty_float(_) |
ty_str |
ty_bare_fn(_) |
ty_closure(_) |
ty_infer(_) |
ty_err |
ty_param(_) |
ty_vec(_, None) => {
false
}
ty_box(typ) | 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, ref 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, _) => {
let upvars = unboxed_closure_upvars(cx, did);
upvars.iter().any(|f| type_requires(cx, seen, r_ty, f.ty))
}
ty_tup(ref ts) => {
ts.iter().any(|t| type_requires(cx, seen, r_ty, *t))
}
ty_enum(ref did, _) if seen.contains(did) => {
false
}
ty_enum(did, ref 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.
#[deriving(PartialEq)]
pub enum Representability {
Representable,
SelfRecursive,
ContainsRecursive,
}
/// 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(cx: &ctxt, sp: Span, ty: t) -> Representability {
// Iterate until something non-representable is found
fn find_nonrepresentable<It: Iterator<t>>(cx: &ctxt, sp: Span, seen: &mut Vec<DefId>,
mut iter: It) -> Representability {
for ty in iter {
let r = type_structurally_recursive(cx, sp, seen, ty);
if r != Representable {
return r
}
}
Representable
}
// Does the type `ty` directly (without indirection through a pointer)
// contain any types on stack `seen`?
fn type_structurally_recursive(cx: &ctxt, sp: Span, seen: &mut Vec<DefId>,
ty: t) -> Representability {
debug!("type_structurally_recursive: {}",
::util::ppaux::ty_to_string(cx, ty));
// Compare current type to previously seen types
match get(ty).sty {
ty_struct(did, _) |
ty_enum(did, _) => {
for (i, &seen_did) in seen.iter().enumerate() {
if did == seen_did {
return if i == 0 { SelfRecursive }
else { ContainsRecursive }
}
}
}
_ => (),
}
// Check inner types
match get(ty).sty {
// Tuples
ty_tup(ref ts) => {
find_nonrepresentable(cx, sp, seen, ts.iter().map(|t| *t))
}
// Fixed-length vectors.
// FIXME(#11924) Behavior undecided for zero-length vectors.
ty_vec(ty, Some(_)) => {
type_structurally_recursive(cx, sp, seen, ty)
}
// Push struct and enum def-ids onto `seen` before recursing.
ty_struct(did, ref substs) => {
seen.push(did);
let fields = struct_fields(cx, did, substs);
let r = find_nonrepresentable(cx, sp, seen,
fields.iter().map(|f| f.mt.ty));
seen.pop();
r
}
ty_enum(did, ref substs) => {
seen.push(did);
let vs = enum_variants(cx, did);
let mut r = Representable;
for variant in vs.iter() {
let iter = variant.args.iter().map(|aty| {
aty.subst_spanned(cx, substs, Some(sp))
});
r = find_nonrepresentable(cx, sp, seen, iter);
if r != Representable { break }
}
seen.pop();
r
}
ty_unboxed_closure(did, _) => {
let upvars = unboxed_closure_upvars(cx, did);
find_nonrepresentable(cx,
sp,
seen,
upvars.iter().map(|f| f.ty))
}
_ => Representable,
}
}
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<DefId> = Vec::new();
type_structurally_recursive(cx, sp, &mut seen, ty)
}
pub fn type_is_trait(ty: t) -> bool {
match get(ty).sty {
ty_uniq(ty) | ty_rptr(_, mt { ty, ..}) => match get(ty).sty {
ty_trait(..) => true,
_ => false
},
ty_trait(..) => true,
_ => false
}
}
pub fn type_is_integral(ty: t) -> bool {
match get(ty).sty {
ty_infer(IntVar(_)) | ty_int(_) | ty_uint(_) => true,
_ => false
}
}
pub fn type_is_uint(ty: t) -> bool {
match get(ty).sty {
ty_infer(IntVar(_)) | ty_uint(ast::TyU) => true,
_ => false
}
}
pub fn type_is_char(ty: t) -> bool {
match get(ty).sty {
ty_char => true,
_ => false
}
}
pub fn type_is_bare_fn(ty: t) -> bool {
match get(ty).sty {
ty_bare_fn(..) => true,
_ => false
}
}
pub fn type_is_fp(ty: t) -> bool {
match get(ty).sty {
ty_infer(FloatVar(_)) | ty_float(_) => true,
_ => false
}
}
pub fn type_is_numeric(ty: t) -> bool {
return type_is_integral(ty) || type_is_fp(ty);
}
pub fn type_is_signed(ty: t) -> bool {
match get(ty).sty {
ty_int(_) => true,
_ => false
}
}
pub fn type_is_machine(ty: t) -> bool {
match get(ty).sty {
ty_int(ast::TyI) | ty_uint(ast::TyU) => false,
ty_int(..) | ty_uint(..) | ty_float(..) => true,
_ => false
}
}
// Is the type's representation size known at compile time?
pub fn type_is_sized(cx: &ctxt, ty: t) -> bool {
type_contents(cx, ty).is_sized(cx)
}
pub fn lltype_is_sized(cx: &ctxt, ty: t) -> bool {
match get(ty).sty {
ty_open(_) => true,
_ => type_contents(cx, ty).is_sized(cx)
}
}
// Return the smallest part of t which is unsized. Fails if t is sized.
// 'Smallest' here means component of the static representation of the type; not
// the size of an object at runtime.
pub fn unsized_part_of_type(cx: &ctxt, ty: t) -> t {
match get(ty).sty {
ty_str | ty_trait(..) | ty_vec(..) => ty,
ty_struct(_, ref substs) => {
// Exactly one of the type parameters must be unsized.
for tp in substs.types.get_slice(subst::TypeSpace).iter() {
if !type_is_sized(cx, *tp) {
return unsized_part_of_type(cx, *tp);
}
}
fail!("Unsized struct type with no unsized type params? {}", ty_to_string(cx, ty));
}
_ => {
assert!(type_is_sized(cx, ty),
"unsized_part_of_type failed even though ty is unsized");
fail!("called unsized_part_of_type with sized ty");
}
}
}
// 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: t) -> bool {
match get(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 *t.
//
// The parameter `explicit` indicates if this is an *explicit* dereference.
// Some types---notably unsafe ptrs---can only be dereferenced explicitly.
pub fn deref(t: t, explicit: bool) -> Option<mt> {
match get(t).sty {
ty_box(ty) | 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 deref_or_dont(t: t) -> t {
match get(t).sty {
ty_box(ty) | ty_uniq(ty) => {
ty
},
ty_rptr(_, mt) | ty_ptr(mt) => mt.ty,
_ => t
}
}
pub fn close_type(cx: &ctxt, t: t) -> t {
match get(t).sty {
ty_open(t) => mk_rptr(cx, ReStatic, mt {ty: t, mutbl:ast::MutImmutable}),
_ => cx.sess.bug(format!("Trying to close a non-open type {}",
ty_to_string(cx, t)).as_slice())
}
}
pub fn type_content(t: t) -> t {
match get(t).sty {
ty_box(ty) | ty_uniq(ty) => ty,
ty_rptr(_, mt) |ty_ptr(mt) => mt.ty,
_ => t
}
}
// Extract the unsized type in an open type (or just return t if it is not open).
pub fn unopen_type(t: t) -> t {
match get(t).sty {
ty_open(t) => t,
_ => t
}
}
// Returns the type of t[i]
pub fn index(ty: t) -> Option<t> {
match get(ty).sty {
ty_vec(t, _) => Some(t),
_ => 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(t: t) -> Option<t> {
match get(t).sty {
ty_vec(t, _) => Some(t),
ty_str => Some(mk_u8()),
_ => None
}
}
pub fn node_id_to_trait_ref(cx: &ctxt, id: ast::NodeId) -> Rc<ty::TraitRef> {
match cx.trait_refs.borrow().find(&id) {
Some(t) => t.clone(),
None => cx.sess.bug(
format!("node_id_to_trait_ref: no trait ref for node `{}`",
cx.map.node_to_string(id)).as_slice())
}
}
pub fn try_node_id_to_type(cx: &ctxt, id: ast::NodeId) -> Option<t> {
cx.node_types.borrow().find_copy(&(id as uint))
}
pub fn node_id_to_type(cx: &ctxt, id: ast::NodeId) -> t {
match try_node_id_to_type(cx, id) {
Some(t) => t,
None => cx.sess.bug(
format!("node_id_to_type: no type for node `{}`",
cx.map.node_to_string(id)).as_slice())
}
}
pub fn node_id_to_type_opt(cx: &ctxt, id: ast::NodeId) -> Option<t> {
match cx.node_types.borrow().find(&(id as uint)) {
Some(&t) => Some(t),
None => None
}
}
pub fn node_id_item_substs(cx: &ctxt, id: ast::NodeId) -> ItemSubsts {
match cx.item_substs.borrow().find(&id) {
None => ItemSubsts::empty(),
Some(ts) => ts.clone(),
}
}
pub fn fn_is_variadic(fty: t) -> bool {
match get(fty).sty {
ty_bare_fn(ref f) => f.sig.variadic,
ty_closure(ref f) => f.sig.variadic,
ref s => {
fail!("fn_is_variadic() called on non-fn type: {:?}", s)
}
}
}
pub fn ty_fn_sig(fty: t) -> FnSig {
match get(fty).sty {
ty_bare_fn(ref f) => f.sig.clone(),
ty_closure(ref f) => f.sig.clone(),
ref s => {
fail!("ty_fn_sig() called on non-fn type: {:?}", s)
}
}
}
/// Returns the ABI of the given function.
pub fn ty_fn_abi(fty: t) -> abi::Abi {
match get(fty).sty {
ty_bare_fn(ref f) => f.abi,
ty_closure(ref f) => f.abi,
_ => fail!("ty_fn_abi() called on non-fn type"),
}
}
// Type accessors for substructures of types
pub fn ty_fn_args(fty: t) -> Vec<t> {
match get(fty).sty {
ty_bare_fn(ref f) => f.sig.inputs.clone(),
ty_closure(ref f) => f.sig.inputs.clone(),
ref s => {
fail!("ty_fn_args() called on non-fn type: {:?}", s)
}
}
}
pub fn ty_closure_store(fty: t) -> TraitStore {
match get(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 => {
fail!("ty_closure_store() called on non-closure type: {:?}", s)
}
}
}
pub fn ty_fn_ret(fty: t) -> t {
match get(fty).sty {
ty_bare_fn(ref f) => f.sig.output,
ty_closure(ref f) => f.sig.output,
ref s => {
fail!("ty_fn_ret() called on non-fn type: {:?}", s)
}
}
}
pub fn is_fn_ty(fty: t) -> bool {
match get(fty).sty {
ty_bare_fn(_) => true,
ty_closure(_) => true,
_ => false
}
}
pub fn ty_region(tcx: &ctxt,
span: Span,
ty: t) -> Region {
match get(ty).sty {
ty_rptr(r, _) => r,
ref s => {
tcx.sess.span_bug(
span,
format!("ty_region() invoked on in appropriate ty: {:?}",
s).as_slice());
}
}
}
pub fn free_region_from_def(free_id: ast::NodeId, def: &RegionParameterDef)
-> ty::Region
{
ty::ReFree(ty::FreeRegion { scope_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(cx: &ctxt, pat: &ast::Pat) -> t {
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(t) -> T with T = int".
pub fn expr_ty(cx: &ctxt, expr: &ast::Expr) -> t {
return node_id_to_type(cx, expr.id);
}
pub fn expr_ty_opt(cx: &ctxt, expr: &ast::Expr) -> Option<t> {
return node_id_to_type_opt(cx, expr.id);
}
pub fn expr_ty_adjusted(cx: &ctxt, expr: &ast::Expr) -> t {
/*!
*
* 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
*/
adjust_ty(cx, expr.span, expr.id, expr_ty(cx, expr),
cx.adjustments.borrow().find(&expr.id),
|method_call| cx.method_map.borrow().find(&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).as_slice());
}
None => {
cx.sess.bug(format!("Node id {} is not present \
in the node map", id).as_slice());
}
}
}
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).as_slice());
}
}
}
r => {
cx.sess.bug(format!("Variable id {} maps to {:?}, not local",
id,
r).as_slice());
}
}
}
pub fn adjust_ty(cx: &ctxt,
span: Span,
expr_id: ast::NodeId,
unadjusted_ty: ty::t,
adjustment: Option<&AutoAdjustment>,
method_type: |typeck::MethodCall| -> Option<ty::t>)
-> ty::t {
/*! See `expr_ty_adjusted` */
return match adjustment {
Some(adjustment) => {
match *adjustment {
AutoAddEnv(store) => {
match ty::get(unadjusted_ty).sty {
ty::ty_bare_fn(ref b) => {
let bounds = ty::ExistentialBounds {
region_bound: ReStatic,
builtin_bounds: all_builtin_bounds(),
};
ty::mk_closure(
cx,
ty::ClosureTy {fn_style: b.fn_style,
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-bare-fn: \
{:?}",
b).as_slice());
}
}
}
AutoDerefRef(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 = typeck::MethodCall::autoderef(expr_id, i);
match method_type(method_call) {
Some(method_ty) => {
adjusted_ty = ty_fn_ret(method_ty);
}
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))
.as_slice());
}
}
}
}
match adj.autoref {
None => adjusted_ty,
Some(ref autoref) => adjust_for_autoref(cx, span, adjusted_ty, autoref)
}
}
}
}
None => unadjusted_ty
};
fn adjust_for_autoref(cx: &ctxt,
span: Span,
ty: ty::t,
autoref: &AutoRef) -> ty::t{
match *autoref {
AutoPtr(r, m, ref a) => {
let adjusted_ty = match a {
&Some(box ref a) => adjust_for_autoref(cx, span, ty, a),
&None => ty
};
mk_rptr(cx, r, mt {
ty: adjusted_ty,
mutbl: m
})
}
AutoUnsafe(m) => {
mk_ptr(cx, mt {ty: ty, mutbl: m})
}
AutoUnsize(ref k) => unsize_ty(cx, ty, k, span),
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(cx: &ctxt,
ty: ty::t,
kind: &UnsizeKind,
span: Span)
-> ty::t {
match kind {
&UnsizeLength(len) => match get(ty).sty {
ty_vec(t, Some(n)) => {
assert!(len == n);
mk_vec(cx, t, None)
}
_ => cx.sess.span_bug(span,
format!("UnsizeLength with bad sty: {}",
ty_to_string(cx, ty)).as_slice())
},
&UnsizeStruct(box ref k, tp_index) => match get(ty).sty {
ty_struct(did, ref 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, unsized_substs)
}
_ => cx.sess.span_bug(span,
format!("UnsizeStruct with bad sty: {}",
ty_to_string(cx, ty)).as_slice())
},
&UnsizeVtable(bounds, def_id, ref substs) => {
mk_trait(cx, def_id, substs.clone(), bounds)
}
}
}
impl AutoRef {
pub fn map_region(&self, f: |Region| -> Region) -> AutoRef {
match *self {
ty::AutoPtr(r, m, None) => ty::AutoPtr(f(r), m, None),
ty::AutoPtr(r, m, Some(ref a)) => ty::AutoPtr(f(r), m, Some(box a.map_region(f))),
ty::AutoUnsize(ref k) => ty::AutoUnsize(k.clone()),
ty::AutoUnsizeUniq(ref k) => ty::AutoUnsizeUniq(k.clone()),
ty::AutoUnsafe(m) => ty::AutoUnsafe(m),
}
}
}
pub fn method_call_type_param_defs<T>(typer: &T,
origin: typeck::MethodOrigin)
-> VecPerParamSpace<TypeParameterDef>
where T: mc::Typer {
match origin {
typeck::MethodStatic(did) => {
ty::lookup_item_type(typer.tcx(), did).generics.types.clone()
}
typeck::MethodStaticUnboxedClosure(did) => {
let def_id = typer.unboxed_closures()
.borrow()
.find(&did)
.expect("method_call_type_param_defs: didn't \
find unboxed closure")
.kind
.trait_did(typer.tcx());
lookup_trait_def(typer.tcx(), def_id).generics.types.clone()
}
typeck::MethodParam(typeck::MethodParam{
trait_id: trt_id,
method_num: n_mth,
..
}) |
typeck::MethodObject(typeck::MethodObject{
trait_id: trt_id,
method_num: n_mth,
..
}) => {
match ty::trait_item(typer.tcx(), trt_id, n_mth) {
ty::MethodTraitItem(method) => method.generics.types.clone(),
}
}
}
}
pub fn resolve_expr(tcx: &ctxt, expr: &ast::Expr) -> def::Def {
match tcx.def_map.borrow().find(&expr.id) {
Some(&def) => def,
None => {
tcx.sess.span_bug(expr.span, format!(
"no def-map entry for expr {:?}", expr.id).as_slice());
}
}
}
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.
pub enum ExprKind {
LvalueExpr,
RvalueDpsExpr,
RvalueDatumExpr,
RvalueStmtExpr
}
pub fn expr_kind(tcx: &ctxt, expr: &ast::Expr) -> ExprKind {
if tcx.method_map.borrow().contains_key(&typeck::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 get(expr_ty(tcx, expr)).sty {
ty_bare_fn(..) => RvalueDatumExpr,
_ => RvalueDpsExpr
}
}
// Fn pointers are just scalar values.
def::DefFn(..) | def::DefStaticMethod(..) => 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::DefBinding(..) |
def::DefUpvar(..) |
def::DefArg(..) |
def::DefLocal(..) => LvalueExpr,
def => {
tcx.sess.span_bug(
expr.span,
format!("uncategorized def for expr {:?}: {:?}",
expr.id,
def).as_slice());
}
}
}
ast::ExprUnary(ast::UnDeref, _) |
ast::ExprField(..) |
ast::ExprIndex(..) => {
LvalueExpr
}
ast::ExprCall(..) |
ast::ExprMethodCall(..) |
ast::ExprStruct(..) |
ast::ExprTup(..) |
ast::ExprIf(..) |
ast::ExprMatch(..) |
ast::ExprFnBlock(..) |
ast::ExprProc(..) |
ast::ExprUnboxedFn(..) |
ast::ExprBlock(..) |
ast::ExprRepeat(..) |
ast::ExprVec(..) => {
RvalueDpsExpr
}
ast::ExprLit(lit) if lit_is_str(lit) => {
RvalueDpsExpr
}
ast::ExprCast(..) => {
match tcx.node_types.borrow().find(&(expr.id as uint)) {
Some(&t) => {
if type_is_trait(t) {
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::ExprAddrOf(..) |
ast::ExprBinary(..) => {
RvalueDatumExpr
}
ast::ExprBox(place, _) => {
// Special case `Box<T>`/`Gc<T>` for now:
let definition = match tcx.def_map.borrow().find(&place.id) {
Some(&def) => def,
None => fail!("no def for place"),
};
let def_id = definition.def_id();
if tcx.lang_items.exchange_heap() == Some(def_id) ||
tcx.lang_items.managed_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(..) => fail!("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.ident.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_ident(f.ident).get().to_string())
.collect::<Vec<String>>()).as_slice());
}
pub fn impl_or_trait_item_idx(id: ast::Ident, trait_items: &[ImplOrTraitItem])
-> Option<uint> {
trait_items.iter().position(|m| m.ident() == id)
}
/// Returns a vector containing the indices of all type parameters that appear
/// in `ty`. The vector may contain duplicates. Probably should be converted
/// to a bitset or some other representation.
pub fn param_tys_in_type(ty: t) -> Vec<ParamTy> {
let mut rslt = Vec::new();
walk_ty(ty, |ty| {
match get(ty).sty {
ty_param(p) => {
rslt.push(p);
}
_ => ()
}
});
rslt
}
pub fn ty_sort_string(cx: &ctxt, t: t) -> String {
match get(t).sty {
ty_nil | ty_bot | ty_bool | ty_char | ty_int(_) |
ty_uint(_) | ty_float(_) | ty_str => {
::util::ppaux::ty_to_string(cx, t)
}
ty_enum(id, _) => format!("enum {}", item_path_str(cx, id)),
ty_box(_) => "Gc-ptr".to_string(),
ty_uniq(_) => "box".to_string(),
ty_vec(_, _) => "vector".to_string(),
ty_ptr(_) => "*-ptr".to_string(),
ty_rptr(_, _) => "&-ptr".to_string(),
ty_bare_fn(_) => "extern fn".to_string(),
ty_closure(_) => "fn".to_string(),
ty_trait(ref inner) => {
format!("trait {}", item_path_str(cx, inner.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_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(),
}
}
pub fn type_err_to_str(cx: &ctxt, err: &type_err) -> String {
/*!
*
* 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. */
fn tstore_to_closure(s: &TraitStore) -> String {
match s {
&UniqTraitStore => "proc".to_string(),
&RegionTraitStore(..) => "closure".to_string()
}
}
match *err {
terr_mismatch => "types differ".to_string(),
terr_fn_style_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_tuple_size(values) => {
format!("expected a tuple with {} elements, \
found one with {} elements",
values.expected,
values.found)
}
terr_record_size(values) => {
format!("expected a record with {} fields, \
found one with {} fields",
values.expected,
values.found)
}
terr_record_mutability => {
"record elements differ in mutability".to_string()
}
terr_record_fields(values) => {
format!("expected a record with field `{}`, found one \
with field `{}`",
token::get_ident(values.expected),
token::get_ident(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) => {
format!("expected {}, found {}",
ty_sort_string(cx, values.expected),
ty_sort_string(cx, values.found))
}
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" })
}
}
}
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(_, 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().find(&id).map(|x| *x)
}
pub fn provided_trait_methods(cx: &ctxt, id: ast::DefId) -> Vec<Rc<Method>> {
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.as_slice());
p.iter()
.map(|m| {
match impl_or_trait_item(
cx,
ast_util::local_def(m.id)) {
MethodTraitItem(m) => m,
}
})
.collect()
}
_ => {
cx.sess.bug(format!("provided_trait_methods: `{}` is \
not a trait",
id).as_slice())
}
}
}
_ => {
cx.sess.bug(format!("provided_trait_methods: `{}` is not a \
trait",
id).as_slice())
}
}
} else {
csearch::get_provided_trait_methods(cx, id)
}
}
fn lookup_locally_or_in_crate_store<V:Clone>(
descr: &str,
def_id: ast::DefId,
map: &mut DefIdMap<V>,
load_external: || -> V) -> V {
/*!
* 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).
*/
match map.find_copy(&def_id) {
Some(v) => { return v; }
None => { }
}
if def_id.krate == ast::LOCAL_CRATE {
fail!("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(cx: &ctxt, trait_did: ast::DefId, idx: uint)
-> ImplOrTraitItem {
let method_def_id = ty::trait_item_def_ids(cx, trait_did).get(idx)
.def_id();
impl_or_trait_item(cx, method_def_id)
}
pub fn trait_items(cx: &ctxt, trait_did: ast::DefId)
-> Rc<Vec<ImplOrTraitItem>> {
let mut trait_items = cx.trait_items_cache.borrow_mut();
match trait_items.find_copy(&trait_did) {
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(cx: &ctxt, id: ast::DefId) -> ImplOrTraitItem {
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)
})
}
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(cx: &ctxt, id: ast::DefId) -> Option<Rc<TraitRef>> {
match cx.impl_trait_cache.borrow().find(&id) {
Some(ret) => { return ret.clone(); }
None => {}
}
let ret = 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) => {
Some(ty::node_id_to_trait_ref(cx, t.ref_id))
}
&None => None
}
}
_ => None
}
}
_ => None
}
} else {
csearch::get_impl_trait(cx, id)
};
cx.impl_trait_cache.borrow_mut().insert(id, ret.clone());
ret
}
pub fn trait_ref_to_def_id(tcx: &ctxt, tr: &ast::TraitRef) -> ast::DefId {
let def = *tcx.def_map.borrow()
.find(&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.add(bound); true }
None => false
}
}
pub fn ty_to_def_id(ty: t) -> Option<ast::DefId> {
match get(ty).sty {
ty_trait(box TyTrait { def_id: id, .. }) |
ty_struct(id, _) |
ty_enum(id, _) |
ty_unboxed_closure(id, _) => Some(id),
_ => None
}
}
// Enum information
#[deriving(Clone)]
pub struct VariantInfo {
pub args: Vec<t>,
pub arg_names: Option<Vec<ast::Ident> >,
pub ctor_ty: t,
pub name: ast::Ident,
pub id: ast::DefId,
pub disr_val: Disr,
pub vis: Visibility
}
impl VariantInfo {
/// 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,
ast_variant: &ast::Variant,
discriminant: Disr) -> VariantInfo {
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: ctor_ty,
name: ast_variant.node.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.as_slice();
assert!(fields.len() > 0);
let arg_tys = ty_fn_args(ctor_ty).iter().map(|a| *a).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: ctor_ty,
name: ast_variant.node.name,
id: ast_util::local_def(ast_variant.node.id),
disr_val: discriminant,
vis: ast_variant.node.vis
};
}
}
}
}
pub fn substd_enum_variants(cx: &ctxt,
id: ast::DefId,
substs: &Substs)
-> Vec<Rc<VariantInfo>> {
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()
}
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().find(&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 {
ty_dtor(cx, struct_id).is_present()
}
pub fn with_path<T>(cx: &ctxt, id: ast::DefId, f: |ast_map::PathElems| -> T) -> 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, t: t) -> bool {
match ty::get(t).sty {
ty_enum(did, _) => (*enum_variants(cx, did)).is_empty(),
_ => false
}
}
pub fn enum_variants(cx: &ctxt, id: ast::DefId) -> Rc<Vec<Rc<VariantInfo>>> {
match cx.enum_var_cache.borrow().find(&id) {
Some(variants) => return variants.clone(),
_ => { /* fallthrough */ }
}
let result = 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(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).as_slice());
}
},
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")
}
};
cx.enum_var_cache.borrow_mut().insert(id, result.clone());
result
}
// Returns information about the enum variant with the given ID:
pub fn enum_variant_with_id(cx: &ctxt,
enum_id: ast::DefId,
variant_id: ast::DefId)
-> Rc<VariantInfo> {
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(cx: &ctxt,
did: ast::DefId)
-> Polytype {
lookup_locally_or_in_crate_store(
"tcache", did, &mut *cx.tcache.borrow_mut(),
|| csearch::get_type(cx, did))
}
pub fn lookup_impl_vtables(cx: &ctxt,
did: ast::DefId)
-> typeck::vtable_res {
lookup_locally_or_in_crate_store(
"impl_vtables", did, &mut *cx.impl_vtables.borrow_mut(),
|| csearch::get_impl_vtables(cx, did) )
}
/// Given the did of a trait, returns its canonical trait ref.
pub fn lookup_trait_def(cx: &ctxt, did: ast::DefId) -> Rc<ty::TraitDef> {
let mut trait_defs = cx.trait_defs.borrow_mut();
match trait_defs.find_copy(&did) {
Some(trait_def) => {
// The item is in this crate. The caller should have added it to the
// type cache already
trait_def
}
None => {
assert!(did.krate != ast::LOCAL_CRATE);
let trait_def = Rc::new(csearch::get_trait_def(cx, did));
trait_defs.insert(did, trait_def.clone());
trait_def
}
}
}
/// Given a reference to a trait, returns the bounds declared on the
/// trait, with appropriate substitutions applied.
pub fn bounds_for_trait_ref(tcx: &ctxt,
trait_ref: &TraitRef)
-> ty::ParamBounds
{
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));
trait_def.bounds.subst(tcx, &trait_ref.substs)
}
/// 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(tcx: &ctxt, did: DefId, f: |&ast::Attribute| -> bool) -> 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) -> Vec<attr::ReprAttr> {
let mut acc = Vec::new();
ty::each_attr(tcx, did, |meta| {
acc.extend(attr::find_repr_attrs(tcx.sess.diagnostic(), meta).move_iter());
true
});
acc
}
// 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: &ctxt,
struct_id: DefId,
id: DefId,
substs: &Substs)
-> ty::t {
let t = if id.krate == ast::LOCAL_CRATE {
node_id_to_type(tcx, id.node)
} else {
let mut tcache = tcx.tcache.borrow_mut();
let pty = tcache.find_or_insert_with(id, |_| {
csearch::get_field_type(tcx, struct_id, id)
});
pty.ty
};
t.subst(tcx, substs)
}
// Lookup all ancestor structs of a struct indicated by did. That is the reflexive,
// transitive closure of doing a single lookup in cx.superstructs.
fn each_super_struct(cx: &ctxt, mut did: ast::DefId, f: |ast::DefId|) {
let superstructs = cx.superstructs.borrow();
loop {
f(did);
match superstructs.find(&did) {
Some(&Some(def_id)) => {
did = def_id;
},
Some(&None) => break,
None => {
cx.sess.bug(
format!("ID not mapped to super-struct: {}",
cx.map.node_to_string(did.node)).as_slice());
}
}
}
}
// Look up the list of field names and IDs for a given struct.
// Fails 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 {
// We store the fields which are syntactically in each struct in cx. So
// we have to walk the inheritance chain of the struct to get all the
// structs (explicit and inherited) for a struct. If this is expensive
// we could cache the whole list of fields here.
let struct_fields = cx.struct_fields.borrow();
let mut results: SmallVector<&[field_ty]> = SmallVector::zero();
each_super_struct(cx, did, |s| {
match struct_fields.find(&s) {
Some(fields) => results.push(fields.as_slice()),
_ => {
cx.sess.bug(
format!("ID not mapped to struct fields: {}",
cx.map.node_to_string(did.node)).as_slice());
}
}
});
let len = results.as_slice().iter().map(|x| x.len()).sum();
let mut result: Vec<field_ty> = Vec::with_capacity(len);
result.extend(results.as_slice().iter().flat_map(|rs| rs.iter().map(|f| f.clone())));
assert!(result.len() == len);
result
} else {
csearch::get_struct_fields(&cx.sess.cstore, did)
}
}
pub fn lookup_struct_field(cx: &ctxt,
parent: ast::DefId,
field_id: ast::DefId)
-> field_ty {
let r = lookup_struct_fields(cx, parent);
match r.iter().find(|f| f.id.node == field_id.node) {
Some(t) => t.clone(),
None => cx.sess.bug("struct ID not found in parent's fields")
}
}
// 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(cx: &ctxt, did: ast::DefId, substs: &Substs)
-> Vec<field> {
lookup_struct_fields(cx, did).iter().map(|f| {
field {
// FIXME #6993: change type of field to Name and get rid of new()
ident: ast::Ident::new(f.name),
mt: mt {
ty: lookup_field_type(cx, did, f.id, substs),
mutbl: MutImmutable
}
}
}).collect()
}
pub struct UnboxedClosureUpvar {
pub def: def::Def,
pub span: Span,
pub ty: t,
}
// Returns a list of `UnboxedClosureUpvar`s for each upvar.
pub fn unboxed_closure_upvars(tcx: &ctxt, closure_id: ast::DefId)
-> Vec<UnboxedClosureUpvar> {
if closure_id.krate == ast::LOCAL_CRATE {
match tcx.freevars.borrow().find(&closure_id.node) {
None => tcx.sess.bug("no freevars for unboxed closure?!"),
Some(ref freevars) => {
freevars.iter().map(|freevar| {
let freevar_def_id = freevar.def.def_id();
UnboxedClosureUpvar {
def: freevar.def,
span: freevar.span,
ty: node_id_to_type(tcx, freevar_def_id.node),
}
}).collect()
}
}
} else {
tcx.sess.bug("unimplemented cross-crate closure upvars")
}
}
pub fn is_binopable(cx: &ctxt, ty: t, op: ast::BinOp) -> bool {
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_bot: int = 5;
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(cx: &ctxt, ty: t) -> int {
if type_is_simd(cx, ty) {
return tycat(cx, simd_type(cx, ty))
}
match get(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_bot => tycat_bot,
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(cx: &ctxt, t: t) -> t {
let u = TypeNormalizer(cx).fold_ty(t);
return u;
struct TypeNormalizer<'a>(&'a ctxt);
impl<'a> TypeFolder for TypeNormalizer<'a> {
fn tcx<'a>(&'a self) -> &'a ctxt { let TypeNormalizer(c) = *self; c }
fn fold_ty(&mut self, t: ty::t) -> ty::t {
match self.tcx().normalized_cache.borrow().find_copy(&t) {
None => {}
Some(u) => return u
}
let t_norm = ty_fold::super_fold_ty(self, t);
self.tcx().normalized_cache.borrow_mut().insert(t, t_norm);
return t_norm;
}
fn fold_region(&mut self, _: ty::Region) -> ty::Region {
ty::ReStatic
}
fn fold_substs(&mut self,
substs: &subst::Substs)
-> subst::Substs {
subst::Substs { regions: subst::ErasedRegions,
types: substs.types.fold_with(self) }
}
fn fold_sig(&mut self,
sig: &ty::FnSig)
-> ty::FnSig {
// The binder-id is only relevant to bound regions, which
// are erased at trans time.
ty::FnSig {
binder_id: ast::DUMMY_NODE_ID,
inputs: sig.inputs.fold_with(self),
output: sig.output.fold_with(self),
variadic: sig.variadic,
}
}
}
}
pub trait ExprTyProvider {
fn expr_ty(&self, ex: &ast::Expr) -> t;
fn ty_ctxt<'a>(&'a self) -> &'a ctxt;
}
impl ExprTyProvider for ctxt {
fn expr_ty(&self, ex: &ast::Expr) -> t {
expr_ty(self, ex)
}
fn ty_ctxt<'a>(&'a self) -> &'a ctxt {
self
}
}
// Returns the repeat count for a repeating vector expression.
pub fn eval_repeat_count<T: ExprTyProvider>(tcx: &T, count_expr: &ast::Expr) -> uint {
match const_eval::eval_const_expr_partial(tcx, count_expr) {
Ok(ref const_val) => match *const_val {
const_eval::const_int(count) => if count < 0 {
tcx.ty_ctxt().sess.span_err(count_expr.span,
"expected positive integer for \
repeat count, found negative integer");
return 0;
} else {
return count as uint
},
const_eval::const_uint(count) => return count as uint,
const_eval::const_float(count) => {
tcx.ty_ctxt().sess.span_err(count_expr.span,
"expected positive integer for \
repeat count, found float");
return count as uint;
}
const_eval::const_str(_) => {
tcx.ty_ctxt().sess.span_err(count_expr.span,
"expected positive integer for \
repeat count, found string");
return 0;
}
const_eval::const_bool(_) => {
tcx.ty_ctxt().sess.span_err(count_expr.span,
"expected positive integer for \
repeat count, found boolean");
return 0;
}
const_eval::const_binary(_) => {
tcx.ty_ctxt().sess.span_err(count_expr.span,
"expected positive integer for \
repeat count, found binary array");
return 0;
}
const_eval::const_nil => {
tcx.ty_ctxt().sess.span_err(count_expr.span,
"expected positive integer for \
repeat count, found ()");
return 0;
}
},
Err(..) => {
tcx.ty_ctxt().sess.span_err(count_expr.span,
"expected constant integer for repeat count, \
found variable");
return 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: &ctxt,
bounds: &[Rc<TraitRef>],
f: |Rc<TraitRef>| -> bool)
-> bool {
for bound_trait_ref in bounds.iter() {
let mut supertrait_set = HashMap::new();
let mut trait_refs = Vec::new();
let mut i = 0;
// Seed the worklist with the trait from the bound
supertrait_set.insert(bound_trait_ref.def_id, ());
trait_refs.push(bound_trait_ref.clone());
// Add the given trait ty to the hash map
while i < trait_refs.len() {
debug!("each_bound_trait_and_supertraits(i={:?}, trait_ref={})",
i, trait_refs.get(i).repr(tcx));
if !f(trait_refs.get(i).clone()) {
return false;
}
// Add supertraits to supertrait_set
let trait_ref = trait_refs.get(i).clone();
let trait_def = lookup_trait_def(tcx, trait_ref.def_id);
for supertrait_ref in trait_def.bounds.trait_bounds.iter() {
let supertrait_ref = supertrait_ref.subst(tcx, &trait_ref.substs);
debug!("each_bound_trait_and_supertraits(supertrait_ref={})",
supertrait_ref.repr(tcx));
let d_id = supertrait_ref.def_id;
if !supertrait_set.contains_key(&d_id) {
// FIXME(#5527) Could have same trait multiple times
supertrait_set.insert(d_id, ());
trait_refs.push(supertrait_ref.clone());
}
}
i += 1;
}
}
return true;
}
pub fn required_region_bounds(tcx: &ctxt,
region_bounds: &[ty::Region],
builtin_bounds: BuiltinBounds,
trait_bounds: &[Rc<TraitRef>])
-> Vec<ty::Region>
{
/*!
* Given a type which must meet the builtin bounds and trait
* bounds, returns a set of lifetimes which the type must outlive.
*
* Requires that trait definitions have been processed.
*/
let mut all_bounds = Vec::new();
debug!("required_region_bounds(builtin_bounds={}, trait_bounds={})",
builtin_bounds.repr(tcx),
trait_bounds.repr(tcx));
all_bounds.push_all(region_bounds);
push_region_bounds([],
builtin_bounds,
&mut all_bounds);
debug!("from builtin bounds: all_bounds={}", all_bounds.repr(tcx));
each_bound_trait_and_supertraits(
tcx,
trait_bounds,
|trait_ref| {
let bounds = ty::bounds_for_trait_ref(tcx, &*trait_ref);
push_region_bounds(bounds.opt_region_bound.as_slice(),
bounds.builtin_bounds,
&mut all_bounds);
debug!("from {}: bounds={} all_bounds={}",
trait_ref.repr(tcx),
bounds.repr(tcx),
all_bounds.repr(tcx));
true
});
return all_bounds;
fn push_region_bounds(region_bounds: &[ty::Region],
builtin_bounds: ty::BuiltinBounds,
all_bounds: &mut Vec<ty::Region>) {
all_bounds.push_all(region_bounds.as_slice());
if builtin_bounds.contains_elem(ty::BoundSend) {
all_bounds.push(ty::ReStatic);
}
}
}
pub fn get_tydesc_ty(tcx: &ctxt) -> Result<t, String> {
tcx.lang_items.require(TyDescStructLangItem).map(|tydesc_lang_item| {
tcx.intrinsic_defs.borrow().find_copy(&tydesc_lang_item)
.expect("Failed to resolve TyDesc")
})
}
pub fn get_opaque_ty(tcx: &ctxt) -> Result<t, String> {
tcx.lang_items.require(OpaqueStructLangItem).map(|opaque_lang_item| {
tcx.intrinsic_defs.borrow().find_copy(&opaque_lang_item)
.expect("Failed to resolve Opaque")
})
}
pub fn visitor_object_ty(tcx: &ctxt,
ptr_region: ty::Region,
trait_region: ty::Region)
-> Result<(Rc<TraitRef>, t), String>
{
let trait_lang_item = match tcx.lang_items.require(TyVisitorTraitLangItem) {
Ok(id) => id,
Err(s) => { return Err(s); }
};
let substs = Substs::empty();
let trait_ref = Rc::new(TraitRef { def_id: trait_lang_item, substs: substs });
Ok((trait_ref.clone(),
mk_rptr(tcx, ptr_region,
mt {mutbl: ast::MutMutable,
ty: mk_trait(tcx,
trait_ref.def_id,
trait_ref.substs.clone(),
ty::region_existential_bound(trait_region))})))
}
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().find(&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
}
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);
}
}
}
}
// 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() {
match tcx.inherent_impls.borrow().find(&type_id) {
Some(implementation_list) => {
implementation_list.borrow_mut().push(impl_def_id);
return;
}
None => {}
}
tcx.inherent_impls.borrow_mut().insert(type_id,
Rc::new(RefCell::new(vec!(impl_def_id))));
}
});
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);
}
}
}
}
// 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().find_copy(&def_id) {
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().find_copy(&def_id) {
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().find(&def_id) {
Some(m) => m.clone(),
None => return None,
};
let name = match impl_item {
MethodTraitItem(method) => method.ident.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.ident().name == name)
.map(|idx| ty::trait_item(tcx, trait_did, idx).id())
}
None => None
}
}
/// Creates a hash of the type `t` 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: &ctxt, t: t, svh: &Svh) -> u64 {
let mut state = sip::SipState::new();
macro_rules! byte( ($b:expr) => { ($b as u8).hash(&mut state) } );
macro_rules! hash( ($e:expr) => { $e.hash(&mut state) } );
let region = |_state: &mut sip::SipState, r: Region| {
match r {
ReStatic => {}
ReEmpty |
ReEarlyBound(..) |
ReLateBound(..) |
ReFree(..) |
ReScope(..) |
ReInfer(..) => {
tcx.sess.bug("non-static 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);
};
ty::walk_ty(t, |t| {
match ty::get(t).sty {
ty_nil => byte!(0),
ty_bot => byte!(1),
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(&mut state, d);
}
ty_box(_) => {
byte!(9);
}
ty_uniq(_) => {
byte!(10);
}
ty_vec(_, Some(n)) => {
byte!(11);
n.hash(&mut state);
}
ty_vec(_, None) => {
byte!(11);
0u8.hash(&mut state);
}
ty_ptr(m) => {
byte!(12);
mt(&mut state, m);
}
ty_rptr(r, m) => {
byte!(13);
region(&mut state, r);
mt(&mut state, m);
}
ty_bare_fn(ref b) => {
byte!(14);
hash!(b.fn_style);
hash!(b.abi);
}
ty_closure(ref c) => {
byte!(15);
hash!(c.fn_style);
hash!(c.onceness);
hash!(c.bounds);
match c.store {
UniqTraitStore => byte!(0),
RegionTraitStore(r, m) => {
byte!(1)
region(&mut state, r);
assert_eq!(m, ast::MutMutable);
}
}
}
ty_trait(box ty::TyTrait { def_id: d, bounds, .. }) => {
byte!(17);
did(&mut state, d);
hash!(bounds);
}
ty_struct(d, _) => {
byte!(18);
did(&mut state, d);
}
ty_tup(ref inner) => {
byte!(19);
hash!(inner.len());
}
ty_param(p) => {
byte!(20);
hash!(p.idx);
did(&mut state, p.def_id);
}
ty_open(_) => byte!(22),
ty_infer(_) => unreachable!(),
ty_err => byte!(23),
ty_unboxed_closure(d, r) => {
byte!(24);
did(&mut state, d);
region(&mut state, r);
}
}
});
state.result()
}
impl Variance {
pub fn to_string(self) -> &'static str {
match self {
Covariant => "+",
Contravariant => "-",
Invariant => "o",
Bivariant => "*",
}
}
}
pub fn construct_parameter_environment(
tcx: &ctxt,
generics: &ty::Generics,
free_id: ast::NodeId)
-> ParameterEnvironment
{
/*! See `ParameterEnvironment` struct def'n for details */
//
// Construct the free substs.
//
// map T => T
let mut types = VecPerParamSpace::empty();
for &space in subst::ParamSpace::all().iter() {
push_types_from_defs(tcx, &mut types, space,
generics.types.get_slice(space));
}
// map bound 'a => free 'a
let mut regions = VecPerParamSpace::empty();
for &space in subst::ParamSpace::all().iter() {
push_region_params(&mut regions, space, free_id,
generics.regions.get_slice(space));
}
let free_substs = Substs {
types: types,
regions: subst::NonerasedRegions(regions)
};
//
// Compute the bounds on Self and the type parameters.
//
let mut bounds = VecPerParamSpace::empty();
for &space in subst::ParamSpace::all().iter() {
push_bounds_from_defs(tcx, &mut bounds, space, &free_substs,
generics.types.get_slice(space));
}
//
// 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.
//
for &space in subst::ParamSpace::all().iter() {
record_region_bounds_from_defs(tcx, space, &free_substs,
generics.regions.get_slice(space));
}
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,
bounds: bounds,
implicit_region_bound: ty::ReScope(free_id),
};
fn push_region_params(regions: &mut VecPerParamSpace<ty::Region>,
space: subst::ParamSpace,
free_id: ast::NodeId,
region_params: &[RegionParameterDef])
{
for r in region_params.iter() {
regions.push(space, ty::free_region_from_def(free_id, r));
}
}
fn push_types_from_defs(tcx: &ty::ctxt,
types: &mut subst::VecPerParamSpace<ty::t>,
space: subst::ParamSpace,
defs: &[TypeParameterDef]) {
for (i, def) in defs.iter().enumerate() {
let ty = ty::mk_param(tcx, space, i, def.def_id);
types.push(space, ty);
}
}
fn push_bounds_from_defs(tcx: &ty::ctxt,
bounds: &mut subst::VecPerParamSpace<ParamBounds>,
space: subst::ParamSpace,
free_substs: &subst::Substs,
defs: &[TypeParameterDef]) {
for def in defs.iter() {
let b = def.bounds.subst(tcx, free_substs);
bounds.push(space, b);
}
}
fn record_region_bounds_from_defs(tcx: &ty::ctxt,
space: subst::ParamSpace,
free_substs: &subst::Substs,
defs: &[RegionParameterDef]) {
for (subst_region, def) in
free_substs.regions().get_slice(space).iter().zip(
defs.iter())
{
// For each region parameter 'subst...
let bounds = def.bounds.subst(tcx, free_substs);
for bound_region in bounds.iter() {
// Which is declared with a bound like 'subst:'bound...
match (subst_region, bound_region) {
(&ty::ReFree(subst_fr), &ty::ReFree(bound_fr)) => {
// Record that 'subst outlives 'bound. Or, put
// another way, 'bound <= 'subst.
tcx.region_maps.relate_free_regions(bound_fr, subst_fr);
},
_ => {
// All named regions are instantiated with free regions.
tcx.sess.bug(
format!("push_region_bounds_from_defs: \
non free region: {} / {}",
subst_region.repr(tcx),
bound_region.repr(tcx)).as_slice());
}
}
}
}
}
}
impl BorrowKind {
pub fn from_mutbl(m: ast::Mutability) -> BorrowKind {
match m {
ast::MutMutable => MutBorrow,
ast::MutImmutable => ImmBorrow,
}
}
pub fn to_user_str(&self) -> &'static str {
match *self {
MutBorrow => "mutable",
ImmBorrow => "immutable",
UniqueImmBorrow => "uniquely immutable",
}
}
}
impl mc::Typer for ty::ctxt {
fn tcx<'a>(&'a self) -> &'a ty::ctxt {
self
}
fn node_ty(&self, id: ast::NodeId) -> mc::McResult<ty::t> {
Ok(ty::node_id_to_type(self, id))
}
fn node_method_ty(&self, method_call: typeck::MethodCall) -> Option<ty::t> {
self.method_map.borrow().find(&method_call).map(|method| method.ty)
}
fn adjustments<'a>(&'a self) -> &'a RefCell<NodeMap<ty::AutoAdjustment>> {
&self.adjustments
}
fn is_method_call(&self, id: ast::NodeId) -> bool {
self.method_map.borrow().contains_key(&typeck::MethodCall::expr(id))
}
fn temporary_scope(&self, rvalue_id: ast::NodeId) -> Option<ast::NodeId> {
self.region_maps.temporary_scope(rvalue_id)
}
fn upvar_borrow(&self, upvar_id: ty::UpvarId) -> ty::UpvarBorrow {
self.upvar_borrow_map.borrow().get_copy(&upvar_id)
}
fn capture_mode(&self, closure_expr_id: ast::NodeId)
-> freevars::CaptureMode {
self.capture_modes.borrow().get_copy(&closure_expr_id)
}
fn unboxed_closures<'a>(&'a self)
-> &'a RefCell<DefIdMap<UnboxedClosure>> {
&self.unboxed_closures
}
}
/// The category of explicit self.
#[deriving(Clone, Eq, PartialEq)]
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>,
typ: t) {
walk_ty(typ, |typ| {
match get(typ).sty {
ty_rptr(region, _) => accumulator.push(region),
ty_enum(_, ref substs) |
ty_trait(box TyTrait {
substs: ref substs,
..
}) |
ty_struct(_, ref substs) => {
match substs.regions {
subst::ErasedRegions => {}
subst::NonerasedRegions(ref regions) => {
for region in regions.iter() {
accumulator.push(*region)
}
}
}
}
ty_closure(ref closure_ty) => {
match closure_ty.store {
RegionTraitStore(region, _) => accumulator.push(region),
UniqTraitStore => {}
}
}
ty_unboxed_closure(_, ref region) => accumulator.push(*region),
ty_nil |
ty_bot |
ty_bool |
ty_char |
ty_int(_) |
ty_uint(_) |
ty_float(_) |
ty_box(_) |
ty_uniq(_) |
ty_str |
ty_vec(_, _) |
ty_ptr(_) |
ty_bare_fn(_) |
ty_tup(_) |
ty_param(_) |
ty_infer(_) |
ty_open(_) |
ty_err => {}
}
})
}