rust/src/librustc/middle/ty.rs
2014-03-08 21:41:32 +01:00

5174 lines
164 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;
use metadata::csearch;
use metadata;
use middle::const_eval;
use middle::lang_items::{ExchangeHeapLangItem, OpaqueStructLangItem};
use middle::lang_items::{TyDescStructLangItem, TyVisitorTraitLangItem};
use middle::freevars;
use middle::resolve;
use middle::resolve_lifetime;
use middle::ty;
use middle::subst::Subst;
use middle::typeck;
use middle::ty_fold;
use middle::ty_fold::TypeFolder;
use middle;
use util::ppaux::{note_and_explain_region, bound_region_ptr_to_str};
use util::ppaux::{trait_store_to_str, ty_to_str, vstore_to_str};
use util::ppaux::{Repr, UserString};
use util::common::{indenter};
use util::nodemap::{NodeMap, NodeSet, DefIdMap, DefIdSet};
use std::cast;
use std::cell::{Cell, RefCell};
use std::cmp;
use std::fmt::Show;
use std::fmt;
use std::hash::{Hash, sip};
use std::ops;
use std::rc::Rc;
use std::vec_ng::Vec;
use std::vec_ng;
use collections::{HashMap, HashSet};
use syntax::ast::*;
use syntax::ast_util::{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::opt_vec::OptVec;
use syntax::opt_vec;
use syntax::abi::AbiSet;
use syntax;
use collections::enum_set::{EnumSet, CLike};
pub type Disr = u64;
pub static INITIAL_DISCRIMINANT_VALUE: Disr = 0;
// Data types
#[deriving(Eq, Hash)]
pub struct field {
ident: ast::Ident,
mt: mt
}
#[deriving(Clone)]
pub enum MethodContainer {
TraitContainer(ast::DefId),
ImplContainer(ast::DefId),
}
#[deriving(Clone)]
pub struct Method {
ident: ast::Ident,
generics: ty::Generics,
fty: BareFnTy,
explicit_self: ast::ExplicitSelf_,
vis: ast::Visibility,
def_id: ast::DefId,
container: MethodContainer,
// If this method is provided, we need to know where it came from
provided_source: Option<ast::DefId>
}
impl Method {
pub fn new(ident: ast::Ident,
generics: ty::Generics,
fty: BareFnTy,
explicit_self: ast::ExplicitSelf_,
vis: ast::Visibility,
def_id: ast::DefId,
container: MethodContainer,
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,
}
}
}
pub struct Impl {
did: DefId,
ident: Ident,
methods: Vec<@Method> }
#[deriving(Clone, Eq, Hash)]
pub struct mt {
ty: t,
mutbl: ast::Mutability,
}
#[deriving(Clone, Eq, Encodable, Decodable, Hash, Show)]
pub enum vstore {
vstore_fixed(uint),
vstore_uniq,
vstore_slice(Region)
}
#[deriving(Clone, Eq, Hash, Encodable, Decodable, Show)]
pub enum TraitStore {
UniqTraitStore, // ~Trait
RegionTraitStore(Region), // &Trait
}
pub struct field_ty {
name: Name,
id: DefId,
vis: ast::Visibility,
}
// Contains information needed to resolve types and (in the future) look up
// the types of AST nodes.
#[deriving(Eq, Hash)]
pub struct creader_cache_key {
cnum: CrateNum,
pos: uint,
len: uint
}
pub type creader_cache = RefCell<HashMap<creader_cache_key, t>>;
pub struct intern_key {
sty: *sty,
}
// NB: Do not replace this with #[deriving(Eq)]. The automatically-derived
// implementation will not recurse through sty and you will get stack
// exhaustion.
impl cmp::Eq 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)
}
}
#[cfg(stage0)]
impl Hash for intern_key {
fn hash(&self, s: &mut sip::SipState) {
unsafe { (*self.sty).hash(s) }
}
}
#[cfg(not(stage0))]
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, Eq, Decodable, Encodable)]
pub struct ItemVariances {
self_param: Option<Variance>,
type_params: OptVec<Variance>,
region_params: OptVec<Variance>
}
#[deriving(Clone, Eq, 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
}
pub enum AutoAdjustment {
AutoAddEnv(ty::Region, ast::Sigil),
AutoDerefRef(AutoDerefRef),
AutoObject(ast::Sigil, Option<ty::Region>,
ast::Mutability,
ty::BuiltinBounds,
ast::DefId, /* Trait ID */
ty::substs /* Trait substitutions */)
}
#[deriving(Decodable, Encodable)]
pub struct AutoDerefRef {
autoderefs: uint,
autoref: Option<AutoRef>
}
#[deriving(Decodable, Encodable)]
pub enum AutoRef {
/// Convert from T to &T
AutoPtr(Region, ast::Mutability),
/// Convert from ~[]/&[] to &[] (or str)
AutoBorrowVec(Region, ast::Mutability),
/// Convert from ~[]/&[] to &&[] (or str)
AutoBorrowVecRef(Region, ast::Mutability),
/// Convert from @fn()/~fn()/|| to ||
AutoBorrowFn(Region),
/// Convert from T to *T
AutoUnsafe(ast::Mutability),
/// Convert from ~Trait/&Trait to &Trait
AutoBorrowObj(Region, ast::Mutability),
}
pub type ctxt = @ctxt_;
/// 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_ {
diag: @syntax::diagnostic::SpanHandler,
// Specifically use a speedy hash algorithm for this hash map, it's used
// quite often.
#[cfg(stage0)]
interner: RefCell<HashMap<intern_key, ~t_box_>>,
#[cfg(not(stage0))]
interner: RefCell<HashMap<intern_key, ~t_box_, ::util::nodemap::FnvHasher>>,
next_id: Cell<uint>,
cstore: @metadata::cstore::CStore,
sess: session::Session,
def_map: resolve::DefMap,
named_region_map: @RefCell<resolve_lifetime::NamedRegionMap>,
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.
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.
node_type_substs: RefCell<NodeMap<Vec<t>>>,
// Maps from a method to the method "descriptor"
methods: RefCell<DefIdMap<@Method>>,
// Maps from a trait def-id to a list of the def-ids of its methods
trait_method_def_ids: RefCell<DefIdMap<@Vec<DefId> >>,
// A cache for the trait_methods() routine
trait_methods_cache: RefCell<DefIdMap<@Vec<@Method> >>,
impl_trait_cache: RefCell<DefIdMap<Option<@ty::TraitRef>>>,
trait_refs: RefCell<NodeMap<@TraitRef>>,
trait_defs: RefCell<DefIdMap<@TraitDef>>,
map: ast_map::Map,
intrinsic_defs: RefCell<DefIdMap<t>>,
freevars: RefCell<freevars::freevar_map>,
tcache: type_cache,
rcache: creader_cache,
short_names_cache: RefCell<HashMap<t, ~str>>,
needs_unwind_cleanup_cache: RefCell<HashMap<t, bool>>,
tc_cache: RefCell<HashMap<uint, TypeContents>>,
ast_ty_to_ty_cache: RefCell<NodeMap<ast_ty_to_ty_cache_entry>>,
enum_var_cache: RefCell<DefIdMap<@Vec<@VariantInfo> >>,
ty_param_defs: RefCell<NodeMap<TypeParameterDef>>,
adjustments: RefCell<NodeMap<@AutoAdjustment>>,
normalized_cache: RefCell<HashMap<t, t>>,
lang_items: @middle::lang_items::LanguageItems,
// A mapping of fake provided method def_ids to the default implementation
provided_method_sources: RefCell<DefIdMap<ast::DefId>>,
supertraits: RefCell<DefIdMap<@Vec<@TraitRef> >>,
// Maps from def-id of a type or region parameter to its
// (inferred) variance.
item_variance_map: RefCell<DefIdMap<@ItemVariances>>,
// 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.
destructor_for_type: RefCell<DefIdMap<ast::DefId>>,
// A method will be in this list if and only if it is a destructor.
destructors: RefCell<DefIdSet>,
// Maps a trait onto a list of impls of that trait.
trait_impls: RefCell<DefIdMap<@RefCell<Vec<@Impl> >>>,
// Maps a def_id 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.
inherent_impls: RefCell<DefIdMap<@RefCell<Vec<@Impl> >>>,
// Maps a def_id of an impl to an Impl structure.
// 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.
impls: RefCell<DefIdMap<@Impl>>,
// Set of used unsafe nodes (functions or blocks). Unsafe nodes not
// present in this set can be warned about.
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.
used_mut_nodes: RefCell<NodeSet>,
// vtable resolution information for impl declarations
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.
populated_external_types: RefCell<DefIdSet>,
// The set of external traits whose implementations have been read. This
// is used for lazy resolution of traits.
populated_external_traits: RefCell<DefIdSet>,
// Borrows
upvar_borrow_map: RefCell<UpvarBorrowMap>,
// These two caches are used by const_eval when decoding external statics
// and variants that are found.
extern_const_statics: RefCell<DefIdMap<Option<@ast::Expr>>>,
extern_const_variants: RefCell<DefIdMap<Option<@ast::Expr>>>,
}
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-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_;
pub struct t_box_ {
sty: sty,
id: uint,
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 {}
#[deriving(Clone, Eq, Hash)]
pub struct t { priv inner: *t_opaque }
impl fmt::Show for t {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.buf.write_str("*t_opaque")
}
}
pub fn get(t: t) -> t_box {
unsafe {
let t2: t_box = cast::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_has_regions(t: t) -> bool {
tbox_has_flag(get(t), has_regions)
}
pub fn type_id(t: t) -> uint { get(t).id }
#[deriving(Clone, Eq, Hash)]
pub struct BareFnTy {
purity: ast::Purity,
abis: AbiSet,
sig: FnSig
}
#[deriving(Clone, Eq, Hash)]
pub struct ClosureTy {
purity: ast::Purity,
sigil: ast::Sigil,
onceness: ast::Onceness,
region: Region,
bounds: BuiltinBounds,
sig: FnSig,
}
/**
* 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, Eq, Hash)]
pub struct FnSig {
binder_id: ast::NodeId,
inputs: Vec<t>,
output: t,
variadic: bool
}
#[deriving(Clone, Eq, Hash)]
pub struct param_ty {
idx: uint,
def_id: DefId
}
/// Representation of regions:
#[deriving(Clone, 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, /*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, Eq, Hash)]
pub struct UpvarId {
var_id: ast::NodeId,
closure_expr_id: ast::NodeId,
}
#[deriving(Clone, Eq, Hash)]
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(Eq, Clone)]
pub struct UpvarBorrow {
kind: BorrowKind,
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, Eq, Ord, TotalEq, TotalOrd, Hash, Encodable, Decodable, Show)]
pub struct FreeRegion {
scope_id: NodeId,
bound_region: BoundRegion
}
#[deriving(Clone, Eq, Ord, TotalEq, TotalOrd, 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),
}
/**
* Represents the values to use when substituting lifetime parameters.
* If the value is `ErasedRegions`, then this subst is occurring during
* trans, and all region parameters will be replaced with `ty::ReStatic`. */
#[deriving(Clone, Eq, Hash)]
pub enum RegionSubsts {
ErasedRegions,
NonerasedRegions(OptVec<ty::Region>)
}
/**
* The type substs represents the kinds of things that can be substituted to
* convert a polytype into a monotype. Note however that substituting bound
* regions other than `self` is done through a different mechanism:
*
* - `tps` represents the type parameters in scope. They are indexed
* according to the order in which they were declared.
*
* - `self_r` indicates the region parameter `self` that is present on nominal
* types (enums, structs) declared as having a region parameter. `self_r`
* should always be none for types that are not region-parameterized and
* Some(_) for types that are. The only bound region parameter that should
* appear within a region-parameterized type is `self`.
*
* - `self_ty` is the type to which `self` should be remapped, if any. The
* `self` type is rather funny in that it can only appear on traits and is
* always substituted away to the implementing type for a trait. */
#[deriving(Clone, Eq, Hash)]
pub struct substs {
self_ty: Option<ty::t>,
tps: Vec<t>,
regions: RegionSubsts,
}
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, Eq, Hash)]
pub enum sty {
ty_nil,
ty_bot,
ty_bool,
ty_char,
ty_int(ast::IntTy),
ty_uint(ast::UintTy),
ty_float(ast::FloatTy),
ty_str(vstore),
ty_enum(DefId, substs),
ty_box(t),
ty_uniq(t),
ty_vec(mt, vstore),
ty_ptr(mt),
ty_rptr(Region, mt),
ty_bare_fn(BareFnTy),
ty_closure(ClosureTy),
ty_trait(DefId, substs, TraitStore, ast::Mutability, BuiltinBounds),
ty_struct(DefId, substs),
ty_tup(Vec<t>),
ty_param(param_ty), // type parameter
ty_self(DefId), /* special, implicit `self` type parameter;
* def_id is the id of the trait */
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)
// "Fake" types, used for trans purposes
ty_unboxed_vec(mt),
}
#[deriving(Eq, Hash)]
pub struct TraitRef {
def_id: DefId,
substs: substs
}
#[deriving(Clone, Eq)]
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> {
expected: T,
found: T
}
// Data structures used in type unification
#[deriving(Clone, Show)]
pub enum type_err {
terr_mismatch,
terr_purity_mismatch(expected_found<Purity>),
terr_onceness_mismatch(expected_found<Onceness>),
terr_abi_mismatch(expected_found<AbiSet>),
terr_mutability,
terr_sigil_mismatch(expected_found<ast::Sigil>),
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_vstores_differ(terr_vstore_kind, expected_found<vstore>),
terr_trait_stores_differ(terr_vstore_kind, expected_found<TraitStore>),
terr_in_field(@type_err, ast::Ident),
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>)
}
#[deriving(Eq, Hash)]
pub struct ParamBounds {
builtin_bounds: BuiltinBounds,
trait_bounds: Vec<@TraitRef> }
pub type BuiltinBounds = EnumSet<BuiltinBound>;
#[deriving(Clone, Encodable, Eq, Decodable, Hash, Show)]
#[repr(uint)]
pub enum BuiltinBound {
BoundStatic,
BoundSend,
BoundFreeze,
BoundSized,
BoundPod,
}
pub fn EmptyBuiltinBounds() -> BuiltinBounds {
EnumSet::empty()
}
pub fn AllBuiltinBounds() -> BuiltinBounds {
let mut set = EnumSet::empty();
set.add(BoundStatic);
set.add(BoundSend);
set.add(BoundFreeze);
set.add(BoundSized);
set
}
impl CLike for BuiltinBound {
fn to_uint(&self) -> uint {
*self as uint
}
fn from_uint(v: uint) -> BuiltinBound {
unsafe { cast::transmute(v) }
}
}
#[deriving(Clone, Eq, Hash)]
pub struct TyVid(uint);
#[deriving(Clone, Eq, Hash)]
pub struct IntVid(uint);
#[deriving(Clone, Eq, Hash)]
pub struct FloatVid(uint);
#[deriving(Clone, Eq, Encodable, Decodable, Hash)]
pub struct RegionVid {
id: uint
}
#[deriving(Clone, Eq, Hash)]
pub enum InferTy {
TyVar(TyVid),
IntVar(IntVid),
FloatVar(FloatVid)
}
#[deriving(Clone, Encodable, Decodable, Hash, Show)]
pub enum InferRegion {
ReVar(RegionVid),
ReSkolemized(uint, BoundRegion)
}
impl cmp::Eq 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))
}
}
pub trait Vid {
fn to_uint(&self) -> uint;
}
impl Vid for TyVid {
fn to_uint(&self) -> uint { let TyVid(v) = *self; v }
}
impl fmt::Show for TyVid {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result{
write!(f.buf, "<generic \\#{}>", self.to_uint())
}
}
impl Vid for IntVid {
fn to_uint(&self) -> uint { let IntVid(v) = *self; v }
}
impl fmt::Show for IntVid {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f.buf, "<generic integer \\#{}>", self.to_uint())
}
}
impl Vid for FloatVid {
fn to_uint(&self) -> uint { let FloatVid(v) = *self; v }
}
impl fmt::Show for FloatVid {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f.buf, "<generic float \\#{}>", self.to_uint())
}
}
impl Vid for RegionVid {
fn to_uint(&self) -> uint { self.id }
}
impl fmt::Show for RegionVid {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
self.id.fmt(f)
}
}
impl fmt::Show for FnSig {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
// grr, without tcx not much we can do.
write!(f.buf, "(...)")
}
}
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)]
pub struct TypeParameterDef {
ident: ast::Ident,
def_id: ast::DefId,
bounds: @ParamBounds,
default: Option<ty::t>
}
#[deriving(Encodable, Decodable, Clone)]
pub struct RegionParameterDef {
ident: ast::Name,
def_id: ast::DefId,
}
/// Information about the type/lifetime parameters associated with an item.
/// Analogous to ast::Generics.
#[deriving(Clone)]
pub struct Generics {
/// List of type parameters declared on the item.
type_param_defs: Rc<Vec<TypeParameterDef> >,
/// List of region parameters declared on the item.
region_param_defs: Rc<Vec<RegionParameterDef> >,
}
impl Generics {
pub fn has_type_params(&self) -> bool {
!self.type_param_defs.borrow().is_empty()
}
pub fn type_param_defs<'a>(&'a self) -> &'a [TypeParameterDef] {
self.type_param_defs.borrow().as_slice()
}
pub fn region_param_defs<'a>(&'a self) -> &'a [RegionParameterDef] {
self.region_param_defs.borrow().as_slice()
}
}
/// When type checking, we use the `ParameterEnvironment` to track
/// details about the type/lifetime parameters that are in scope.
/// It primarily stores the bounds information.
///
/// Note: This information might seem to be redundant with the data in
/// `tcx.ty_param_defs`, but it is not. That table contains the
/// parameter definitions from an "outside" perspective, but this
/// struct will contain the bounds for a parameter as seen from inside
/// the function body. Currently the only real distinction is that
/// bound lifetime parameters are replaced with free ones, but in the
/// future I hope to refine the representation of types so as to make
/// more distinctions clearer.
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.
free_substs: ty::substs,
/// Bound on the Self parameter
self_param_bound: Option<@TraitRef>,
/// Bounds on each numbered type parameter
type_param_bounds: Vec<ParamBounds> ,
}
/// A polytype.
///
/// - `bounds`: The list of bounds for each type parameter. The length of the
/// list also tells you how many type parameters there are.
///
/// - `rp`: true if the type is region-parameterized. Types can have at
/// most one region parameter, always called `&self`.
///
/// - `ty`: the base type. May have reference to the (unsubstituted) bound
/// region `&self` or to (unsubstituted) ty_param types
#[deriving(Clone)]
pub struct ty_param_bounds_and_ty {
generics: Generics,
ty: t
}
/// As `ty_param_bounds_and_ty` but for a trait ref.
pub struct TraitDef {
generics: Generics,
bounds: BuiltinBounds,
trait_ref: @ty::TraitRef,
}
pub struct ty_param_substs_and_ty {
substs: ty::substs,
ty: ty::t
}
pub type type_cache = RefCell<DefIdMap<ty_param_bounds_and_ty>>;
pub type node_type_table = RefCell<HashMap<uint,t>>;
pub fn mk_ctxt(s: session::Session,
dm: resolve::DefMap,
named_region_map: @RefCell<resolve_lifetime::NamedRegionMap>,
map: ast_map::Map,
freevars: freevars::freevar_map,
region_maps: middle::region::RegionMaps,
lang_items: @middle::lang_items::LanguageItems)
-> ctxt {
#[cfg(stage0)]
fn hasher() -> HashMap<intern_key, ~t_box_> {
HashMap::new()
}
#[cfg(not(stage0))]
fn hasher() -> HashMap<intern_key, ~t_box_, ::util::nodemap::FnvHasher> {
HashMap::with_hasher(::util::nodemap::FnvHasher)
}
@ctxt_ {
named_region_map: named_region_map,
item_variance_map: RefCell::new(DefIdMap::new()),
diag: s.diagnostic(),
interner: RefCell::new(hasher()),
next_id: Cell::new(primitives::LAST_PRIMITIVE_ID),
cstore: s.cstore,
sess: s,
def_map: dm,
region_maps: region_maps,
node_types: RefCell::new(HashMap::new()),
node_type_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()),
methods: RefCell::new(DefIdMap::new()),
trait_method_def_ids: RefCell::new(DefIdMap::new()),
trait_methods_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()),
supertraits: 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()),
impls: 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()),
}
}
// 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 };
{
let mut interner = cx.interner.borrow_mut();
match interner.get().find(&key) {
Some(t) => unsafe { return cast::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;
for tt in substs.tps.iter() { f |= get(*tt).flags; }
match substs.regions {
ErasedRegions => {}
NonerasedRegions(ref regions) => {
for r in regions.iter() {
f |= rflags(*r)
}
}
}
return f;
}
match &st {
&ty_str(vstore_slice(r)) => {
flags |= rflags(r);
}
&ty_vec(ref mt, vstore_slice(r)) => {
flags |= rflags(r);
flags |= get(mt.ty).flags;
}
&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(_) => flags |= has_params as uint,
&ty_infer(_) => flags |= needs_infer as uint,
&ty_self(_) => flags |= has_self as uint,
&ty_enum(_, ref substs) | &ty_struct(_, ref substs) |
&ty_trait(_, ref substs, _, _, _) => {
flags |= sflags(substs);
match st {
ty_trait(_, _, RegionTraitStore(r), _, _) => {
flags |= rflags(r);
}
_ => {}
}
}
&ty_box(tt) | &ty_uniq(tt) => {
flags |= get(tt).flags
}
&ty_vec(ref m, _) | &ty_ptr(ref m) |
&ty_unboxed_vec(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) => {
flags |= rflags(f.region);
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);
}
}
let t = ~t_box_ {
sty: st,
id: cx.next_id.get(),
flags: flags,
};
let sty_ptr = &t.sty as *sty;
let key = intern_key {
sty: sty_ptr,
};
let mut interner = cx.interner.borrow_mut();
interner.get().insert(key, t);
cx.next_id.set(cx.next_id.get() + 1);
unsafe {
cast::transmute::<*sty, t>(sty_ptr)
}
}
#[inline]
pub fn mk_prim_t(primitive: &'static t_box_) -> t {
unsafe {
cast::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: vstore) -> t {
mk_t(cx, ty_str(t))
}
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, tm: mt, t: vstore) -> t {
mk_t(cx, ty_vec(tm, t))
}
pub fn mk_unboxed_vec(cx: ctxt, tm: mt) -> t {
mk_t(cx, ty_unboxed_vec(tm))
}
pub fn mk_mut_unboxed_vec(cx: ctxt, ty: t) -> t {
mk_t(cx, ty_unboxed_vec(mt {ty: ty, mutbl: ast::MutImmutable}))
}
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(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.map(|t| *t);
mk_bare_fn(cx,
BareFnTy {
purity: ast::ImpureFn,
abis: AbiSet::Rust(),
sig: FnSig {
binder_id: binder_id,
inputs: Vec::from_slice(input_args),
output: output,
variadic: false
}
})
}
pub fn mk_trait(cx: ctxt,
did: ast::DefId,
substs: substs,
store: TraitStore,
mutability: ast::Mutability,
bounds: BuiltinBounds)
-> t {
// take a copy of substs so that we own the vectors inside
mk_t(cx, ty_trait(did, substs, store, mutability, bounds))
}
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_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_self(cx: ctxt, did: ast::DefId) -> t { mk_t(cx, ty_self(did)) }
pub fn mk_param(cx: ctxt, n: uint, k: DefId) -> t {
mk_t(cx, ty_param(param_ty { idx: n, def_id: k }))
}
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_self(_) |
ty_infer(_) | ty_param(_) | ty_err => {}
ty_box(ty) | ty_uniq(ty) => maybe_walk_ty(ty, f),
ty_vec(ref tm, _) | ty_unboxed_vec(ref tm) | ty_ptr(ref tm) |
ty_rptr(_, ref tm) => {
maybe_walk_ty(tm.ty, f);
}
ty_enum(_, ref substs) | ty_struct(_, ref substs) |
ty_trait(_, ref substs, _, _, _) => {
for subty in (*substs).tps.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)
}
pub fn fold_regions(cx: ctxt, ty: t, fldr: |r: Region| -> Region) -> t {
ty_fold::RegionFolder::regions(cx, fldr).fold_ty(ty)
}
// Substitute *only* type parameters. Used in trans where regions are erased.
pub fn subst_tps(tcx: ctxt, tps: &[t], self_ty_opt: Option<t>, typ: t) -> t {
let mut subst = TpsSubst { tcx: tcx, self_ty_opt: self_ty_opt, tps: tps };
return subst.fold_ty(typ);
struct TpsSubst<'a> {
tcx: ctxt,
self_ty_opt: Option<t>,
tps: &'a [t],
}
impl<'a> TypeFolder for TpsSubst<'a> {
fn tcx(&self) -> ty::ctxt { self.tcx }
fn fold_ty(&mut self, t: ty::t) -> ty::t {
if self.tps.len() == 0u && self.self_ty_opt.is_none() {
return t;
}
let tb = ty::get(t);
if self.self_ty_opt.is_none() && !tbox_has_flag(tb, has_params) {
return t;
}
match ty::get(t).sty {
ty_param(p) => {
self.tps[p.idx]
}
ty_self(_) => {
match self.self_ty_opt {
None => self.tcx.sess.bug("ty_self unexpected here"),
Some(self_ty) => self_ty
}
}
_ => {
ty_fold::super_fold_ty(self, t)
}
}
}
}
}
pub fn substs_is_noop(substs: &substs) -> bool {
let regions_is_noop = match substs.regions {
ErasedRegions => false, // may be used to canonicalize
NonerasedRegions(ref regions) => regions.is_empty()
};
substs.tps.len() == 0u &&
regions_is_noop &&
substs.self_ty.is_none()
}
pub fn substs_to_str(cx: ctxt, substs: &substs) -> ~str {
substs.repr(cx)
}
pub fn subst(cx: ctxt,
substs: &substs,
typ: t)
-> t {
typ.subst(cx, substs)
}
// 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.self_ty.iter().any(|&t| type_is_error(t)) ||
tref.substs.tps.iter().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_self(..) => true,
_ => false
}
}
pub fn type_is_structural(ty: t) -> bool {
match get(ty).sty {
ty_struct(..) | ty_tup(_) | ty_enum(..) | ty_closure(_) | ty_trait(..) |
ty_vec(_, vstore_fixed(_)) | ty_str(vstore_fixed(_)) |
ty_vec(_, vstore_slice(_)) | ty_str(vstore_slice(_))
=> true,
_ => false
}
}
pub fn type_is_sequence(ty: t) -> bool {
match get(ty).sty {
ty_str(_) | ty_vec(_, _) => true,
_ => false
}
}
pub fn type_is_simd(cx: ctxt, ty: t) -> bool {
match get(ty).sty {
ty_struct(did, _) => lookup_simd(cx, did),
_ => false
}
}
pub fn type_is_str(ty: t) -> bool {
match get(ty).sty {
ty_str(_) => true,
_ => false
}
}
pub fn sequence_element_type(cx: ctxt, ty: t) -> t {
match get(ty).sty {
ty_str(_) => return mk_mach_uint(ast::TyU8),
ty_vec(mt, _) | ty_unboxed_vec(mt) => return mt.ty,
_ => cx.sess.bug("sequence_element_type called on non-sequence value"),
}
}
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 get_element_type(ty: t, i: uint) -> t {
match get(ty).sty {
ty_tup(ref ts) => return *ts.get(i),
_ => fail!("get_element_type called on invalid type")
}
}
pub fn type_is_box(ty: t) -> bool {
match get(ty).sty {
ty_box(_) => return true,
_ => return false
}
}
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_slice(ty: t) -> bool {
match get(ty).sty {
ty_vec(_, vstore_slice(_)) | ty_str(vstore_slice(_)) => true,
_ => return false
}
}
pub fn type_is_unique_box(ty: t) -> bool {
match get(ty).sty {
ty_uniq(_) => return true,
_ => return false
}
}
pub fn type_is_unsafe_ptr(ty: t) -> bool {
match get(ty).sty {
ty_ptr(_) => return true,
_ => return false
}
}
pub fn type_is_vec(ty: t) -> bool {
return match get(ty).sty {
ty_vec(_, _) | ty_unboxed_vec(_) => true,
ty_str(_) => true,
_ => false
};
}
pub fn type_is_unique(ty: t) -> bool {
match get(ty).sty {
ty_uniq(_) | ty_vec(_, vstore_uniq) | ty_str(vstore_uniq) => 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
}
}
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 {
{
let needs_unwind_cleanup_cache = cx.needs_unwind_cleanup_cache
.borrow();
match needs_unwind_cleanup_cache.get().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);
let mut needs_unwind_cleanup_cache = cx.needs_unwind_cleanup_cache
.borrow_mut();
needs_unwind_cleanup_cache.get().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 = subst(cx, substs, *aty);
needs_unwind_cleanup |=
type_needs_unwind_cleanup_(cx, t, tycache,
encountered_box);
}
}
!needs_unwind_cleanup
}
ty_uniq(_) |
ty_str(vstore_uniq) |
ty_vec(_, vstore_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 {
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__00000000__0000,
// Things that are interior to the value (first nibble):
InteriorUnsized = 0b0000__00000000__0001,
// InteriorAll = 0b0000__00000000__1111,
// Things that are owned by the value (second and third nibbles):
OwnsOwned = 0b0000__00000001__0000,
OwnsDtor = 0b0000__00000010__0000,
OwnsManaged /* see [1] below */ = 0b0000__00000100__0000,
OwnsAffine = 0b0000__00001000__0000,
OwnsAll = 0b0000__11111111__0000,
// Things that are reachable by the value in any way (fourth nibble):
ReachesNonsendAnnot = 0b0001__00000000__0000,
ReachesBorrowed = 0b0010__00000000__0000,
// ReachesManaged /* see [1] below */ = 0b0100__00000000__0000,
ReachesMutable = 0b1000__00000000__0000,
ReachesAll = 0b1111__00000000__0000,
// Things that cause values to *move* rather than *copy*
Moves = 0b0000__00001011__0000,
// Things that mean drop glue is necessary
NeedsDrop = 0b0000__00000111__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 = 0b0111__00000100__0000,
// Things that prevent values from being considered freezable
Nonfreezable = 0b1000__00000000__0000,
// Things that prevent values from being considered 'static
Nonstatic = 0b0010__00000000__0000,
// Things that prevent values from being considered sized
Nonsized = 0b0000__00000000__0001,
// Things that make values considered not POD (would be same
// as `Moves`, but for the fact that managed data `@` is
// not considered POD)
Nonpod = 0b0000__00001111__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 = 0b0100__00000100__0000,
// All bits
All = 0b1111__11111111__1111
}
)
impl TypeContents {
pub fn meets_bounds(&self, cx: ctxt, bbs: BuiltinBounds) -> bool {
bbs.iter().all(|bb| self.meets_bound(cx, bb))
}
pub fn meets_bound(&self, cx: ctxt, bb: BuiltinBound) -> bool {
match bb {
BoundStatic => self.is_static(cx),
BoundFreeze => self.is_freezable(cx),
BoundSend => self.is_sendable(cx),
BoundSized => self.is_sized(cx),
BoundPod => self.is_pod(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_static(&self, _: ctxt) -> bool {
!self.intersects(TC::Nonstatic)
}
pub fn is_sendable(&self, _: ctxt) -> bool {
!self.intersects(TC::Nonsendable)
}
pub fn owns_managed(&self) -> bool {
self.intersects(TC::OwnsManaged)
}
pub fn owns_owned(&self) -> bool {
self.intersects(TC::OwnsOwned)
}
pub fn is_freezable(&self, _: ctxt) -> bool {
!self.intersects(TC::Nonfreezable)
}
pub fn is_sized(&self, _: ctxt) -> bool {
!self.intersects(TC::Nonsized)
}
pub fn is_pod(&self, _: ctxt) -> bool {
!self.intersects(TC::Nonpod)
}
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 `~` 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 inverse(&self) -> TypeContents {
TypeContents { bits: !self.bits }
}
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.buf, "TypeContents({:t})", self.bits)
}
}
pub fn type_has_dtor(cx: ctxt, t: ty::t) -> bool {
type_contents(cx, t).has_dtor()
}
pub fn type_is_static(cx: ctxt, t: ty::t) -> bool {
type_contents(cx, t).is_static(cx)
}
pub fn type_is_sendable(cx: ctxt, t: ty::t) -> bool {
type_contents(cx, t).is_sendable(cx)
}
pub fn type_is_freezable(cx: ctxt, t: ty::t) -> bool {
type_contents(cx, t).is_freezable(cx)
}
pub fn type_contents(cx: ctxt, ty: t) -> TypeContents {
let ty_id = type_id(ty);
{
let tc_cache = cx.tc_cache.borrow();
match tc_cache.get().find(&ty_id) {
Some(tc) => { return *tc; }
None => {}
}
}
let mut cache = HashMap::new();
let result = tc_ty(cx, ty, &mut cache);
let mut tc_cache = cx.tc_cache.borrow_mut();
tc_cache.get().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: ~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 => {}
}
{
let tc_cache = cx.tc_cache.borrow();
match tc_cache.get().find(&ty_id) { // Must check both caches!
Some(tc) => { return *tc; }
None => {}
}
}
cache.insert(ty_id, TC::None);
let result = match get(ty).sty {
// Scalar and unique types are sendable, freezable, and durable
ty_nil | ty_bot | ty_bool | ty_int(_) | ty_uint(_) | ty_float(_) |
ty_bare_fn(_) | ty::ty_char => {
TC::None
}
ty_str(vstore_uniq) => {
TC::OwnsOwned
}
ty_closure(ref c) => {
closure_contents(cx, c)
}
ty_box(typ) => {
tc_ty(cx, typ, cache).managed_pointer()
}
ty_uniq(typ) => {
tc_ty(cx, typ, cache).owned_pointer()
}
ty_trait(_, _, store, mutbl, bounds) => {
object_contents(cx, store, mutbl, bounds)
}
ty_ptr(ref mt) => {
tc_ty(cx, mt.ty, cache).unsafe_pointer()
}
ty_rptr(r, ref mt) => {
tc_ty(cx, mt.ty, cache).reference(
borrowed_contents(r, mt.mutbl))
}
ty_vec(mt, vstore_uniq) => {
tc_mt(cx, mt, cache).owned_pointer()
}
ty_vec(ref mt, vstore_slice(r)) => {
tc_ty(cx, mt.ty, cache).reference(
borrowed_contents(r, mt.mutbl))
}
ty_vec(mt, vstore_fixed(_)) => {
tc_mt(cx, mt, cache)
}
ty_str(vstore_slice(r)) => {
borrowed_contents(r, ast::MutImmutable)
}
ty_str(vstore_fixed(_)) => {
TC::None
}
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 ty::has_dtor(cx, did) {
res = res | TC::OwnsDtor;
}
apply_lang_items(cx, did, res)
}
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 res =
TypeContents::union(variants.as_slice(), |variant| {
TypeContents::union(variant.args.as_slice(),
|arg_ty| {
tc_ty(cx, *arg_ty, cache)
})
});
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().get(&p.def_id.node);
kind_bounds_to_contents(cx,
tp_def.bounds.builtin_bounds,
tp_def.bounds.trait_bounds.as_slice())
}
ty_self(def_id) => {
// FIXME(#4678)---self should just be a ty param
// Self may be bounded if the associated trait has builtin kinds
// for supertraits. If so we can use those bounds.
let trait_def = lookup_trait_def(cx, def_id);
let traits = [trait_def.trait_ref];
kind_bounds_to_contents(cx, trait_def.bounds, traits)
}
ty_infer(_) => {
// This occurs during coherence, but shouldn't occur at other
// times.
TC::All
}
ty_unboxed_vec(mt) => TC::InteriorUnsized | tc_mt(cx, mt, cache),
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_freeze_bound() {
tc | TC::ReachesMutable
} else 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_pod_bound() {
tc | TC::OwnsAffine
} 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 = match cty.sigil {
ast::BorrowedSigil =>
object_contents(cx, RegionTraitStore(cty.region), MutMutable, cty.bounds),
ast::OwnedSigil =>
object_contents(cx, UniqTraitStore, MutImmutable, cty.bounds),
ast::ManagedSigil => unreachable!()
};
// FIXME(#3569): This borrowed_contents call should be taken care of in
// object_contents, after ~Traits and @Traits can have region bounds too.
// This one here is redundant for &fns but important for ~fns and @fns.
let rt = borrowed_contents(cty.region, ast::MutImmutable);
// 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 | rt | ot
}
fn object_contents(cx: ctxt,
store: TraitStore,
mutbl: ast::Mutability,
bounds: BuiltinBounds)
-> TypeContents {
// These are the type contents of the (opaque) interior
let contents = TC::ReachesMutable.when(mutbl == ast::MutMutable) |
kind_bounds_to_contents(cx, bounds, []);
match store {
UniqTraitStore => {
contents.owned_pointer()
}
RegionTraitStore(r) => {
contents.reference(borrowed_contents(r, mutbl))
}
}
}
fn kind_bounds_to_contents(cx: ctxt,
bounds: BuiltinBounds,
traits: &[@TraitRef])
-> TypeContents {
let _i = indenter();
let mut tc = TC::All;
each_inherited_builtin_bound(cx, bounds, traits, |bound| {
tc = tc - match bound {
BoundStatic => TC::Nonstatic,
BoundSend => TC::Nonsendable,
BoundFreeze => TC::Nonfreezable,
BoundSized => TC::Nonsized,
BoundPod => TC::Nonpod,
};
});
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: &[@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.iter() {
f(bound);
}
true
});
}
}
}
pub fn type_moves_by_default(cx: ctxt, ty: t) -> bool {
type_contents(cx, ty).moves_by_default(cx)
}
// 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_str(cx, r_ty),
::util::ppaux::ty_to_str(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_str(cx, r_ty),
::util::ppaux::ty_to_str(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_str(cx, r_ty),
::util::ppaux::ty_to_str(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
// possibilty to have length zero.
ty_vec(_, vstore_fixed(0)) => false, // don't need no contents
ty_vec(mt, vstore_fixed(_)) => type_requires(cx, seen, r_ty, mt.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_self(_) |
ty_vec(_, _) |
ty_unboxed_vec(_) => {
false
}
ty_box(typ) | ty_uniq(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_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 = subst(cx, substs, *aty);
type_requires(cx, seen, r_ty, sty)
})
});
seen.pop().unwrap();
r
}
};
debug!("subtypes_require({}, {})? {}",
::util::ppaux::ty_to_str(cx, r_ty),
::util::ppaux::ty_to_str(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(Eq)]
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, ty: t) -> Representability {
// Iterate until something non-representable is found
fn find_nonrepresentable<It: Iterator<t>>(cx: ctxt, seen: &mut Vec<DefId> ,
mut iter: It) -> Representability {
for ty in iter {
let r = type_structurally_recursive(cx, 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, seen: &mut Vec<DefId> ,
ty: t) -> Representability {
debug!("type_structurally_recursive: {}",
::util::ppaux::ty_to_str(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, seen, ts.iter().map(|t| *t))
}
// Fixed-length vectors.
// FIXME(#11924) Behavior undecided for zero-length vectors.
ty_vec(mt, vstore_fixed(_)) => {
type_structurally_recursive(cx, seen, mt.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, 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| subst(cx, substs, *aty));
r = find_nonrepresentable(cx, seen, iter);
if r != Representable { break }
}
seen.pop();
r
}
_ => Representable,
}
}
debug!("is_type_representable: {}",
::util::ppaux::ty_to_str(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, &mut seen, ty)
}
pub fn type_is_trait(ty: t) -> bool {
match get(ty).sty {
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_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
}
}
pub fn type_is_enum(ty: t) -> bool {
match get(ty).sty {
ty_enum(_, _) => return true,
_ => return false
}
}
// Is the type's representation size known at compile time?
pub fn type_is_sized(cx: ctxt, ty: ty::t) -> bool {
match get(ty).sty {
// FIXME(#6308) add trait, vec, str, etc here.
ty_param(p) => {
let ty_param_defs = cx.ty_param_defs.borrow();
let param_def = ty_param_defs.get().get(&p.def_id.node);
if param_def.bounds.builtin_bounds.contains_elem(BoundSized) {
return true;
}
return false;
},
_ => return true,
}
}
// 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
}
}
pub fn type_param(ty: t) -> Option<uint> {
match get(ty).sty {
ty_param(p) => return Some(p.idx),
_ => {/* fall through */ }
}
return None;
}
// 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> {
deref_sty(&get(t).sty, explicit)
}
pub fn deref_sty(sty: &sty, explicit: bool) -> Option<mt> {
match *sty {
ty_box(typ) | ty_uniq(typ) => {
Some(mt {
ty: typ,
mutbl: ast::MutImmutable,
})
}
ty_rptr(_, mt) => {
Some(mt)
}
ty_ptr(mt) if explicit => {
Some(mt)
}
_ => None
}
}
pub fn type_autoderef(t: t) -> t {
let mut t = t;
loop {
match deref(t, false) {
None => return t,
Some(mt) => t = mt.ty
}
}
}
// Returns the type and mutability of t[i]
pub fn index(t: t) -> Option<mt> {
index_sty(&get(t).sty)
}
pub fn index_sty(sty: &sty) -> Option<mt> {
match *sty {
ty_vec(mt, _) => Some(mt),
ty_str(_) => Some(mt {ty: mk_u8(), mutbl: ast::MutImmutable}),
_ => None
}
}
pub fn node_id_to_trait_ref(cx: ctxt, id: ast::NodeId) -> @ty::TraitRef {
let trait_refs = cx.trait_refs.borrow();
match trait_refs.get().find(&id) {
Some(&t) => t,
None => cx.sess.bug(
format!("node_id_to_trait_ref: no trait ref for node `{}`",
cx.map.node_to_str(id)))
}
}
pub fn try_node_id_to_type(cx: ctxt, id: ast::NodeId) -> Option<t> {
let node_types = cx.node_types.borrow();
node_types.get().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_str(id)))
}
}
pub fn node_id_to_type_opt(cx: ctxt, id: ast::NodeId) -> Option<t> {
let node_types = cx.node_types.borrow();
debug!("id: {:?}, node_types: {:?}", id, node_types);
match node_types.get().find(&(id as uint)) {
Some(&t) => Some(t),
None => None
}
}
// FIXME(pcwalton): Makes a copy, bleh. Probably better to not do that.
pub fn node_id_to_type_params(cx: ctxt, id: ast::NodeId) -> Vec<t> {
let node_type_substs = cx.node_type_substs.borrow();
match node_type_substs.get().find(&id) {
None => return Vec::new(),
Some(ts) => return (*ts).clone(),
}
}
fn node_id_has_type_params(cx: ctxt, id: ast::NodeId) -> bool {
let node_type_substs = cx.node_type_substs.borrow();
node_type_substs.get().contains_key(&id)
}
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)
}
}
}
// 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_sigil(fty: t) -> Sigil {
match get(fty).sty {
ty_closure(ref f) => f.sigil,
ref s => {
fail!("ty_closure_sigil() called on non-closure type: {:?}", s)
}
}
}
pub fn ty_fn_purity(fty: t) -> ast::Purity {
match get(fty).sty {
ty_bare_fn(ref f) => f.purity,
ty_closure(ref f) => f.purity,
ref s => {
fail!("ty_fn_purity() called on non-fn 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_vstore(ty: t) -> vstore {
match get(ty).sty {
ty_vec(_, vstore) => vstore,
ty_str(vstore) => vstore,
ref s => fail!("ty_vstore() called on invalid sty: {:?}", s)
}
}
pub fn ty_region(tcx: ctxt,
span: Span,
ty: t) -> Region {
match get(ty).sty {
ty_rptr(r, _) => r,
ty_vec(_, vstore_slice(r)) => r,
ty_str(vstore_slice(r)) => r,
ref s => {
tcx.sess.span_bug(
span,
format!("ty_region() invoked on in appropriate ty: {:?}", s));
}
}
}
pub fn replace_fn_sig(cx: ctxt, fsty: &sty, new_sig: FnSig) -> t {
match *fsty {
ty_bare_fn(ref f) => mk_bare_fn(cx, BareFnTy {sig: new_sig, ..*f}),
ty_closure(ref f) => mk_closure(cx, ClosureTy {sig: new_sig, ..*f}),
ref s => {
cx.sess.bug(
format!("ty_fn_sig() called on non-fn type: {:?}", s));
}
}
}
pub fn replace_closure_return_type(tcx: ctxt, fn_type: t, ret_type: t) -> t {
/*!
*
* Returns a new function type based on `fn_type` but returning a value of
* type `ret_type` instead. */
match ty::get(fn_type).sty {
ty::ty_closure(ref fty) => {
ty::mk_closure(tcx, ClosureTy {
sig: FnSig {output: ret_type, ..fty.sig.clone()},
..(*fty).clone()
})
}
_ => {
tcx.sess.bug(format!(
"replace_fn_ret() invoked with non-fn-type: {}",
ty_to_str(tcx, fn_type)));
}
}
}
// Returns a vec of all the input and output types of fty.
pub fn tys_in_fn_sig(sig: &FnSig) -> Vec<t> {
vec_ng::append_one(sig.inputs.map(|a| *a), sig.output)
}
// Type accessors for AST nodes
pub fn block_ty(cx: ctxt, b: &ast::Block) -> t {
return node_id_to_type(cx, b.id);
}
// 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". If this isn't what you want, see
// expr_ty_params_and_ty() below.
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
*/
let unadjusted_ty = expr_ty(cx, expr);
let adjustment = {
let adjustments = cx.adjustments.borrow();
adjustments.get().find_copy(&expr.id)
};
adjust_ty(cx, expr.span, unadjusted_ty, adjustment)
}
pub fn expr_span(cx: ctxt, id: NodeId) -> Span {
match cx.map.find(id) {
Some(ast_map::NodeExpr(e)) => {
e.span
}
Some(f) => {
cx.sess.bug(format!("Node id {} is not an expr: {:?}",
id, f));
}
None => {
cx.sess.bug(format!("Node id {} is not present \
in the node map", id));
}
}
}
pub fn local_var_name_str(cx: ctxt, id: NodeId) -> InternedString {
match cx.map.find(id) {
Some(ast_map::NodeLocal(pat)) => {
match pat.node {
ast::PatIdent(_, ref path, _) => {
token::get_ident(ast_util::path_to_ident(path))
}
_ => {
cx.sess.bug(
format!("Variable id {} maps to {:?}, not local",
id, pat));
}
}
}
r => {
cx.sess.bug(
format!("Variable id {} maps to {:?}, not local",
id, r));
}
}
}
pub fn adjust_ty(cx: ctxt,
span: Span,
unadjusted_ty: ty::t,
adjustment: Option<@AutoAdjustment>)
-> ty::t {
/*! See `expr_ty_adjusted` */
return match adjustment {
None => unadjusted_ty,
Some(adjustment) => {
match *adjustment {
AutoAddEnv(r, s) => {
match ty::get(unadjusted_ty).sty {
ty::ty_bare_fn(ref b) => {
ty::mk_closure(
cx,
ty::ClosureTy {purity: b.purity,
sigil: s,
onceness: ast::Many,
region: r,
bounds: ty::AllBuiltinBounds(),
sig: b.sig.clone()})
}
ref b => {
cx.sess.bug(
format!("add_env adjustment on non-bare-fn: \
{:?}",
b));
}
}
}
AutoDerefRef(ref adj) => {
let mut adjusted_ty = unadjusted_ty;
if !ty::type_is_error(adjusted_ty) {
for i in range(0, adj.autoderefs) {
match ty::deref(adjusted_ty, true) {
Some(mt) => { adjusted_ty = mt.ty; }
None => {
cx.sess.span_bug(
span,
format!("the {}th autoderef failed: \
{}",
i,
ty_to_str(cx, adjusted_ty)));
}
}
}
}
match adj.autoref {
None => adjusted_ty,
Some(ref autoref) => {
match *autoref {
AutoPtr(r, m) => {
mk_rptr(cx, r, mt {
ty: adjusted_ty,
mutbl: m
})
}
AutoBorrowVec(r, m) => {
borrow_vec(cx, span, r, m, adjusted_ty)
}
AutoBorrowVecRef(r, m) => {
adjusted_ty = borrow_vec(cx,
span,
r,
m,
adjusted_ty);
mk_rptr(cx, r, mt {
ty: adjusted_ty,
mutbl: ast::MutImmutable
})
}
AutoBorrowFn(r) => {
borrow_fn(cx, span, r, adjusted_ty)
}
AutoUnsafe(m) => {
mk_ptr(cx, mt {ty: adjusted_ty, mutbl: m})
}
AutoBorrowObj(r, m) => {
borrow_obj(cx, span, r, m, adjusted_ty)
}
}
}
}
}
AutoObject(ref sigil, ref region, m, b, def_id, ref substs) => {
trait_adjustment_to_ty(cx,
sigil,
region,
def_id,
substs,
m,
b)
}
}
}
};
fn borrow_vec(cx: ctxt, span: Span,
r: Region, m: ast::Mutability,
ty: ty::t) -> ty::t {
match get(ty).sty {
ty_vec(mt, _) => {
ty::mk_vec(cx, mt {ty: mt.ty, mutbl: m}, vstore_slice(r))
}
ty_str(_) => {
ty::mk_str(cx, vstore_slice(r))
}
ref s => {
cx.sess.span_bug(
span,
format!("borrow-vec associated with bad sty: {:?}",
s));
}
}
}
fn borrow_fn(cx: ctxt, span: Span, r: Region, ty: ty::t) -> ty::t {
match get(ty).sty {
ty_closure(ref fty) => {
ty::mk_closure(cx, ClosureTy {
sigil: BorrowedSigil,
region: r,
..(*fty).clone()
})
}
ref s => {
cx.sess.span_bug(
span,
format!("borrow-fn associated with bad sty: {:?}",
s));
}
}
}
fn borrow_obj(cx: ctxt, span: Span, r: Region,
m: ast::Mutability, ty: ty::t) -> ty::t {
match get(ty).sty {
ty_trait(trt_did, ref trt_substs, _, _, b) => {
ty::mk_trait(cx, trt_did, trt_substs.clone(),
RegionTraitStore(r), m, b)
}
ref s => {
cx.sess.span_bug(
span,
format!("borrow-trait-obj associated with bad sty: {:?}",
s));
}
}
}
}
pub fn trait_adjustment_to_ty(cx: ctxt, sigil: &ast::Sigil, region: &Option<Region>,
def_id: ast::DefId, substs: &substs, m: ast::Mutability,
bounds: BuiltinBounds) -> t {
let trait_store = match *sigil {
BorrowedSigil => RegionTraitStore(region.expect("expected valid region")),
OwnedSigil => UniqTraitStore,
ManagedSigil => unreachable!()
};
mk_trait(cx, def_id, substs.clone(), trait_store, m, bounds)
}
impl AutoRef {
pub fn map_region(&self, f: |Region| -> Region) -> AutoRef {
match *self {
ty::AutoPtr(r, m) => ty::AutoPtr(f(r), m),
ty::AutoBorrowVec(r, m) => ty::AutoBorrowVec(f(r), m),
ty::AutoBorrowVecRef(r, m) => ty::AutoBorrowVecRef(f(r), m),
ty::AutoBorrowFn(r) => ty::AutoBorrowFn(f(r)),
ty::AutoUnsafe(m) => ty::AutoUnsafe(m),
ty::AutoBorrowObj(r, m) => ty::AutoBorrowObj(f(r), m),
}
}
}
pub struct ParamsTy {
params: Vec<t>,
ty: t
}
pub fn expr_ty_params_and_ty(cx: ctxt,
expr: &ast::Expr)
-> ParamsTy {
ParamsTy {
params: node_id_to_type_params(cx, expr.id),
ty: node_id_to_type(cx, expr.id)
}
}
pub fn expr_has_ty_params(cx: ctxt, expr: &ast::Expr) -> bool {
return node_id_has_type_params(cx, expr.id);
}
pub fn method_call_type_param_defs(tcx: ctxt, origin: typeck::MethodOrigin)
-> Rc<Vec<TypeParameterDef> > {
match origin {
typeck::MethodStatic(did) => {
// n.b.: When we encode impl methods, the bounds
// that we encode include both the impl bounds
// and then the method bounds themselves...
ty::lookup_item_type(tcx, did).generics.type_param_defs
}
typeck::MethodParam(typeck::MethodParam {
trait_id: trt_id,
method_num: n_mth, ..}) |
typeck::MethodObject(typeck::MethodObject {
trait_id: trt_id,
method_num: n_mth, ..}) => {
// ...trait methods bounds, in contrast, include only the
// method bounds, so we must preprend the tps from the
// trait itself. This ought to be harmonized.
let trait_type_param_defs =
lookup_trait_def(tcx, trt_id).generics.type_param_defs();
Rc::new(vec_ng::append(
Vec::from_slice(trait_type_param_defs),
ty::trait_method(tcx,
trt_id,
n_mth).generics.type_param_defs()))
}
}
}
pub fn resolve_expr(tcx: ctxt, expr: &ast::Expr) -> ast::Def {
let def_map = tcx.def_map.borrow();
match def_map.get().find(&expr.id) {
Some(&def) => def,
None => {
tcx.sess.span_bug(expr.span, format!(
"no def-map entry for expr {:?}", expr.id));
}
}
}
pub fn expr_is_lval(tcx: ctxt,
method_map: typeck::MethodMap,
e: &ast::Expr) -> bool {
match expr_kind(tcx, method_map, 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,
method_map: typeck::MethodMap,
expr: &ast::Expr) -> ExprKind {
{
let method_map = method_map.borrow();
if method_map.get().contains_key(&expr.id) {
// Overloaded operations are generally calls, and hence they are
// generated via DPS. However, assign_op (e.g., `x += y`) is an
// exception, as its result is always unit.
return match expr.node {
ast::ExprAssignOp(..) => RvalueStmtExpr,
ast::ExprUnary(ast::UnDeref, _) => LvalueExpr,
_ => RvalueDpsExpr
};
}
}
match expr.node {
ast::ExprPath(..) => {
match resolve_expr(tcx, expr) {
ast::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
}
}
ast::DefStruct(_) => {
match get(expr_ty(tcx, expr)).sty {
ty_bare_fn(..) => RvalueDatumExpr,
_ => RvalueDpsExpr
}
}
// Fn pointers are just scalar values.
ast::DefFn(..) | ast::DefStaticMethod(..) => RvalueDatumExpr,
// Note: there is actually a good case to be made that
// DefArg's, particularly those of immediate type, ought to
// considered rvalues.
ast::DefStatic(..) |
ast::DefBinding(..) |
ast::DefUpvar(..) |
ast::DefArg(..) |
ast::DefLocal(..) => LvalueExpr,
def => {
tcx.sess.span_bug(expr.span, format!(
"uncategorized def for expr {:?}: {:?}",
expr.id, def));
}
}
}
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::ExprBlock(..) |
ast::ExprRepeat(..) |
ast::ExprVstore(_, ast::ExprVstoreSlice) |
ast::ExprVstore(_, ast::ExprVstoreMutSlice) |
ast::ExprVec(..) => {
RvalueDpsExpr
}
ast::ExprLit(lit) if lit_is_str(lit) => {
RvalueDpsExpr
}
ast::ExprCast(..) => {
let node_types = tcx.node_types.borrow();
match node_types.get().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, ~Foo, or &Foo.
RvalueDatumExpr
}
}
}
ast::ExprBreak(..) |
ast::ExprAgain(..) |
ast::ExprRet(..) |
ast::ExprWhile(..) |
ast::ExprLoop(..) |
ast::ExprAssign(..) |
ast::ExprInlineAsm(..) |
ast::ExprAssignOp(..) => {
RvalueStmtExpr
}
ast::ExprForLoop(..) => fail!("non-desugared expr_for_loop"),
ast::ExprLogLevel |
ast::ExprLit(_) | // Note: LitStr is carved out above
ast::ExprUnary(..) |
ast::ExprAddrOf(..) |
ast::ExprBinary(..) |
ast::ExprVstore(_, ast::ExprVstoreUniq) => {
RvalueDatumExpr
}
ast::ExprBox(place, _) => {
// Special case `~T` for now:
let def_map = tcx.def_map.borrow();
let definition = match def_map.get().find(&place.id) {
Some(&def) => def,
None => fail!("no def for place"),
};
let def_id = ast_util::def_id_of_def(definition);
match tcx.lang_items.items.get(ExchangeHeapLangItem as uint) {
&Some(item_def_id) if def_id == item_def_id => {
RvalueDatumExpr
}
&Some(_) | &None => RvalueDpsExpr,
}
}
ast::ExprParen(e) => expr_kind(tcx, method_map, 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(name: ast::Name, fields: &[field]) -> Option<uint> {
let mut i = 0u;
for f in fields.iter() { if f.ident.name == name { return Some(i); } i += 1u; }
return None;
}
pub fn field_idx_strict(tcx: ty::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.map(|f| token::get_ident(f.ident).get().to_str())));
}
pub fn method_idx(id: ast::Ident, meths: &[@Method]) -> Option<uint> {
meths.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<param_ty> {
let mut rslt = Vec::new();
walk_ty(ty, |ty| {
match get(ty).sty {
ty_param(p) => {
rslt.push(p);
}
_ => ()
}
});
rslt
}
pub fn occurs_check(tcx: ctxt, sp: Span, vid: TyVid, rt: t) {
// Returns a vec of all the type variables occurring in `ty`. It may
// contain duplicates. (Integral type vars aren't counted.)
fn vars_in_type(ty: t) -> Vec<TyVid> {
let mut rslt = Vec::new();
walk_ty(ty, |ty| {
match get(ty).sty {
ty_infer(TyVar(v)) => rslt.push(v),
_ => ()
}
});
rslt
}
// Fast path
if !type_needs_infer(rt) { return; }
// Occurs check!
if vars_in_type(rt).contains(&vid) {
// Maybe this should be span_err -- however, there's an
// assertion later on that the type doesn't contain
// variables, so in this case we have to be sure to die.
tcx.sess.span_fatal
(sp, ~"type inference failed because I \
could not find a type\n that's both of the form "
+ ::util::ppaux::ty_to_str(tcx, mk_var(tcx, vid)) +
" and of the form " + ::util::ppaux::ty_to_str(tcx, rt) +
" - such a type would have to be infinitely large.");
}
}
pub fn ty_sort_str(cx: ctxt, t: t) -> ~str {
match get(t).sty {
ty_nil | ty_bot | ty_bool | ty_char | ty_int(_) |
ty_uint(_) | ty_float(_) | ty_str(_) => {
::util::ppaux::ty_to_str(cx, t)
}
ty_enum(id, _) => format!("enum {}", item_path_str(cx, id)),
ty_box(_) => ~"@-ptr",
ty_uniq(_) => ~"~-ptr",
ty_vec(_, _) => ~"vector",
ty_unboxed_vec(_) => ~"unboxed vector",
ty_ptr(_) => ~"*-ptr",
ty_rptr(_, _) => ~"&-ptr",
ty_bare_fn(_) => ~"extern fn",
ty_closure(_) => ~"fn",
ty_trait(id, _, _, _, _) => format!("trait {}", item_path_str(cx, id)),
ty_struct(id, _) => format!("struct {}", item_path_str(cx, id)),
ty_tup(_) => ~"tuple",
ty_infer(TyVar(_)) => ~"inferred type",
ty_infer(IntVar(_)) => ~"integral variable",
ty_infer(FloatVar(_)) => ~"floating-point variable",
ty_param(_) => ~"type parameter",
ty_self(_) => ~"self",
ty_err => ~"type error"
}
}
pub fn type_err_to_str(cx: ctxt, err: &type_err) -> ~str {
/*!
*
* 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 terr_vstore_kind_to_str(k: terr_vstore_kind) -> ~str {
match k {
terr_vec => ~"[]",
terr_str => ~"str",
terr_fn => ~"fn",
terr_trait => ~"trait"
}
}
match *err {
terr_mismatch => ~"types differ",
terr_purity_mismatch(values) => {
format!("expected {} fn but found {} fn",
values.expected.to_str(), values.found.to_str())
}
terr_abi_mismatch(values) => {
format!("expected {} fn but found {} fn",
values.expected.to_str(), values.found.to_str())
}
terr_onceness_mismatch(values) => {
format!("expected {} fn but found {} fn",
values.expected.to_str(), values.found.to_str())
}
terr_sigil_mismatch(values) => {
format!("expected {} closure, found {} closure",
values.expected.to_str(),
values.found.to_str())
}
terr_mutability => ~"values differ in mutability",
terr_box_mutability => ~"boxed values differ in mutability",
terr_vec_mutability => ~"vectors differ in mutability",
terr_ptr_mutability => ~"pointers differ in mutability",
terr_ref_mutability => ~"references differ in mutability",
terr_ty_param_size(values) => {
format!("expected a type with {} type params \
but found one with {} type params",
values.expected, values.found)
}
terr_tuple_size(values) => {
format!("expected a tuple with {} elements \
but found one with {} elements",
values.expected, values.found)
}
terr_record_size(values) => {
format!("expected a record with {} fields \
but found one with {} fields",
values.expected, values.found)
}
terr_record_mutability => {
~"record elements differ in mutability"
}
terr_record_fields(values) => {
format!("expected a record with field `{}` but found one with field \
`{}`",
token::get_ident(values.expected),
token::get_ident(values.found))
}
terr_arg_count => ~"incorrect number of function parameters",
terr_regions_does_not_outlive(..) => {
format!("lifetime mismatch")
}
terr_regions_not_same(..) => {
format!("lifetimes are not the same")
}
terr_regions_no_overlap(..) => {
format!("lifetimes do not intersect")
}
terr_regions_insufficiently_polymorphic(br, _) => {
format!("expected bound lifetime parameter {}, \
but found concrete lifetime",
bound_region_ptr_to_str(cx, br))
}
terr_regions_overly_polymorphic(br, _) => {
format!("expected concrete lifetime, \
but found bound lifetime parameter {}",
bound_region_ptr_to_str(cx, br))
}
terr_vstores_differ(k, ref values) => {
format!("{} storage differs: expected `{}` but found `{}`",
terr_vstore_kind_to_str(k),
vstore_to_str(cx, (*values).expected),
vstore_to_str(cx, (*values).found))
}
terr_trait_stores_differ(_, ref values) => {
format!("trait storage differs: expected `{}` but found `{}`",
trait_store_to_str(cx, (*values).expected),
trait_store_to_str(cx, (*values).found))
}
terr_in_field(err, fname) => {
format!("in field `{}`, {}", token::get_ident(fname),
type_err_to_str(cx, err))
}
terr_sorts(values) => {
format!("expected {} but found {}",
ty_sort_str(cx, values.expected),
ty_sort_str(cx, values.found))
}
terr_traits(values) => {
format!("expected trait `{}` but 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 but found `{}`",
values.found.user_string(cx))
} else if values.found.is_empty() {
format!("expected bounds `{}` but found no bounds",
values.expected.user_string(cx))
} else {
format!("expected bounds `{}` but found bounds `{}`",
values.expected.user_string(cx),
values.found.user_string(cx))
}
}
terr_integer_as_char => {
format!("expected an integral type but found `char`")
}
terr_int_mismatch(ref values) => {
format!("expected `{}` but found `{}`",
values.expected.to_str(),
values.found.to_str())
}
terr_float_mismatch(ref values) => {
format!("expected `{}` but found `{}`",
values.expected.to_str(),
values.found.to_str())
}
terr_variadic_mismatch(ref values) => {
format!("expected {} fn but 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 def_has_ty_params(def: ast::Def) -> bool {
match def {
ast::DefFn(_, _) | ast::DefVariant(_, _, _) | ast::DefStruct(_)
=> true,
_ => false
}
}
pub fn provided_source(cx: ctxt, id: ast::DefId) -> Option<ast::DefId> {
let provided_method_sources = cx.provided_method_sources.borrow();
provided_method_sources.get().find(&id).map(|x| *x)
}
pub fn provided_trait_methods(cx: ctxt, id: ast::DefId) -> Vec<@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| method(cx, ast_util::local_def(m.id)))
.collect()
}
_ => {
cx.sess.bug(format!("provided_trait_methods: \
`{:?}` is not a trait",
id))
}
}
}
_ => {
cx.sess.bug(format!("provided_trait_methods: `{:?}` is not \
a trait",
id))
}
}
}
} else {
csearch::get_provided_trait_methods(cx, id)
}
}
pub fn trait_supertraits(cx: ctxt, id: ast::DefId) -> @Vec<@TraitRef> {
// Check the cache.
{
let supertraits = cx.supertraits.borrow();
match supertraits.get().find(&id) {
Some(&trait_refs) => { return trait_refs; }
None => {} // Continue.
}
}
// Not in the cache. It had better be in the metadata, which means it
// shouldn't be local.
assert!(!is_local(id));
// Get the supertraits out of the metadata and create the
// TraitRef for each.
let result = @csearch::get_supertraits(cx, id);
let mut supertraits = cx.supertraits.borrow_mut();
supertraits.get().insert(id, result);
return result;
}
pub fn trait_ref_supertraits(cx: ctxt, trait_ref: &ty::TraitRef) -> Vec<@TraitRef> {
let supertrait_refs = trait_supertraits(cx, trait_ref.def_id);
supertrait_refs.map(
|supertrait_ref| supertrait_ref.subst(cx, &trait_ref.substs))
}
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.methods`, `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_method(cx: ctxt, trait_did: ast::DefId, idx: uint) -> @Method {
let method_def_id = *ty::trait_method_def_ids(cx, trait_did).get(idx);
ty::method(cx, method_def_id)
}
pub fn trait_methods(cx: ctxt, trait_did: ast::DefId) -> @Vec<@Method> {
let mut trait_methods_cache = cx.trait_methods_cache.borrow_mut();
match trait_methods_cache.get().find(&trait_did) {
Some(&methods) => methods,
None => {
let def_ids = ty::trait_method_def_ids(cx, trait_did);
let methods = @def_ids.map(|d| ty::method(cx, *d));
trait_methods_cache.get().insert(trait_did, methods);
methods
}
}
}
pub fn method(cx: ctxt, id: ast::DefId) -> @Method {
let mut methods = cx.methods.borrow_mut();
lookup_locally_or_in_crate_store("methods", id, methods.get(), || {
@csearch::get_method(cx, id)
})
}
pub fn trait_method_def_ids(cx: ctxt, id: ast::DefId) -> @Vec<DefId> {
let mut trait_method_def_ids = cx.trait_method_def_ids.borrow_mut();
lookup_locally_or_in_crate_store("trait_method_def_ids",
id,
trait_method_def_ids.get(),
|| {
@csearch::get_trait_method_def_ids(cx.cstore, id)
})
}
pub fn impl_trait_ref(cx: ctxt, id: ast::DefId) -> Option<@TraitRef> {
{
let mut impl_trait_cache = cx.impl_trait_cache.borrow_mut();
match impl_trait_cache.get().find(&id) {
Some(&ret) => { return ret; }
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)
};
let mut impl_trait_cache = cx.impl_trait_cache.borrow_mut();
impl_trait_cache.get().insert(id, ret);
return ret;
}
pub fn trait_ref_to_def_id(tcx: ctxt, tr: &ast::TraitRef) -> ast::DefId {
let def_map = tcx.def_map.borrow();
let def = def_map.get()
.find(&tr.ref_id)
.expect("no def-map entry for trait");
ast_util::def_id_of_def(*def)
}
pub fn try_add_builtin_trait(tcx: ctxt,
trait_def_id: ast::DefId,
builtin_bounds: &mut BuiltinBounds) -> 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(id, _, _, _, _) | ty_struct(id, _) | ty_enum(id, _) => Some(id),
_ => None
}
}
// Enum information
#[deriving(Clone)]
pub struct VariantInfo {
args: Vec<t>,
arg_names: Option<Vec<ast::Ident> >,
ctor_ty: t,
name: ast::Ident,
id: ast::DefId,
disr_val: Disr,
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).map(|a| *a)
} 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).map(|a| *a);
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<@VariantInfo> {
enum_variants(cx, id).iter().map(|variant_info| {
let substd_args = variant_info.args.iter()
.map(|aty| subst(cx, substs, *aty)).collect();
let substd_ctor_ty = subst(cx, substs, variant_info.ctor_ty);
@VariantInfo {
args: substd_args,
ctor_ty: substd_ctor_ty,
..(**variant_info).clone()
}
}).collect()
}
pub fn item_path_str(cx: ctxt, id: ast::DefId) -> ~str {
with_path(cx, id, |path| ast_map::path_to_str(path))
}
pub enum DtorKind {
NoDtor,
TraitDtor(DefId, bool)
}
impl DtorKind {
pub fn is_not_present(&self) -> bool {
match *self {
NoDtor => true,
_ => false
}
}
pub fn is_present(&self) -> bool {
!self.is_not_present()
}
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 {
let destructor_for_type = cx.destructor_for_type.borrow();
match destructor_for_type.get().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) -> @Vec<@VariantInfo> {
{
let enum_var_cache = cx.enum_var_cache.borrow();
match enum_var_cache.get().find(&id) {
Some(&variants) => return variants,
_ => { /* fallthrough */ }
}
}
let result = if ast::LOCAL_CRATE != id.krate {
@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;
@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(e) => match const_eval::eval_const_expr_partial(&cx, e) {
Ok(const_eval::const_int(val)) => {
discriminant = val as Disr
}
Ok(const_eval::const_uint(val)) => {
discriminant = val as Disr
}
Ok(_) => {
cx.sess
.span_err(e.span,
"expected signed integer \
constant");
}
Err(ref err) => {
cx.sess
.span_err(e.span,
format!("expected \
constant: {}",
*err));
}
},
None => {}
};
let variant_info =
@VariantInfo::from_ast_variant(cx,
variant,
discriminant);
last_discriminant = Some(discriminant);
variant_info
}).collect()
}
_ => {
cx.sess.bug("enum_variants: id not bound to an enum")
}
}
}
_ => cx.sess.bug("enum_variants: id not bound to an enum")
}
}
};
{
let mut enum_var_cache = cx.enum_var_cache.borrow_mut();
enum_var_cache.get().insert(id, result);
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)
-> @VariantInfo {
let variants = enum_variants(cx, enum_id);
let mut i = 0;
while i < variants.len() {
let variant = *variants.get(i);
if variant.id == variant_id {
return variant
}
i += 1;
}
cx.sess.bug("enum_variant_with_id(): no variant exists with that ID");
}
// 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)
-> ty_param_bounds_and_ty {
let mut tcache = cx.tcache.borrow_mut();
lookup_locally_or_in_crate_store(
"tcache", did, tcache.get(),
|| csearch::get_type(cx, did))
}
pub fn lookup_impl_vtables(cx: ctxt,
did: ast::DefId)
-> typeck::impl_res {
let mut impl_vtables = cx.impl_vtables.borrow_mut();
lookup_locally_or_in_crate_store(
"impl_vtables", did, impl_vtables.get(),
|| 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) -> @ty::TraitDef {
let mut trait_defs = cx.trait_defs.borrow_mut();
match trait_defs.get().find(&did) {
Some(&trait_def) => {
// The item is in this crate. The caller should have added it to the
// type cache already
return trait_def;
}
None => {
assert!(did.krate != ast::LOCAL_CRATE);
let trait_def = @csearch::get_trait_def(cx, did);
trait_defs.get().insert(did, trait_def);
return trait_def;
}
}
}
/// Iterate over meta_items 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: |@MetaItem| -> bool) -> bool {
if is_local(did) {
let item = tcx.map.expect_item(did.node);
item.attrs.iter().advance(|attr| f(attr.node.value))
} else {
let mut cont = true;
csearch::get_item_attrs(tcx.cstore, did, |meta_items| {
if cont {
cont = meta_items.iter().advance(|ptrptr| f(*ptrptr));
}
});
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.name().equiv(&attr) {
found = true;
false
} else {
true
}
});
found
}
/// Determine whether an item is annotated with `#[packed]`
pub fn lookup_packed(tcx: ctxt, did: DefId) -> bool {
has_attr(tcx, did, "packed")
}
/// 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 definition.
pub fn lookup_repr_hint(tcx: ctxt, did: DefId) -> attr::ReprAttr {
let mut acc = attr::ReprAny;
ty::each_attr(tcx, did, |meta| {
acc = attr::find_repr_attr(tcx.sess.diagnostic(), meta, acc);
true
});
return 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();
match tcache.get().find(&id) {
Some(&ty_param_bounds_and_ty {ty, ..}) => ty,
None => {
let tpt = csearch::get_field_type(tcx, struct_id, id);
tcache.get().insert(id, tpt.clone());
tpt.ty
}
}
}
};
subst(tcx, substs, t)
}
// 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 {
{
match cx.map.find(did.node) {
Some(ast_map::NodeItem(i)) => {
match i.node {
ast::ItemStruct(struct_def, _) => {
struct_field_tys(struct_def.fields.as_slice())
}
_ => cx.sess.bug("struct ID bound to non-struct")
}
}
Some(ast_map::NodeVariant(ref variant)) => {
match (*variant).node.kind {
ast::StructVariantKind(struct_def) => {
struct_field_tys(struct_def.fields.as_slice())
}
_ => {
cx.sess.bug("struct ID bound to enum variant that isn't \
struct-like")
}
}
}
_ => {
cx.sess.bug(
format!("struct ID not bound to an item: {}",
cx.map.node_to_str(did.node)));
}
}
}
} else {
return 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,
None => cx.sess.bug("struct ID not found in parent's fields")
}
}
fn struct_field_tys(fields: &[StructField]) -> Vec<field_ty> {
fields.iter().map(|field| {
match field.node.kind {
NamedField(ident, visibility) => {
field_ty {
name: ident.name,
id: ast_util::local_def(field.node.id),
vis: visibility,
}
}
UnnamedField => {
field_ty {
name: syntax::parse::token::special_idents::unnamed_field.name,
id: ast_util::local_def(field.node.id),
vis: ast::Public,
}
}
}
}).collect()
}
// 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).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
}
}
})
}
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;
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_mult,
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
/*other*/ [f, f, f, f, f, f, f, f],
/*bool*/ [f, f, f, f, t, t, t, t],
/*char*/ [f, f, f, f, t, t, f, f],
/*int*/ [t, t, t, t, t, t, t, f],
/*float*/ [t, t, t, f, t, t, f, f],
/*bot*/ [t, t, t, t, t, t, t, t],
/*raw ptr*/ [f, f, f, f, t, t, f, f]];
return tbl[tycat(cx, ty)][opcat(op)];
}
pub fn ty_params_to_tys(tcx: ty::ctxt, generics: &ast::Generics) -> Vec<t> {
Vec::from_fn(generics.ty_params.len(), |i| {
let id = generics.ty_params.get(i).id;
ty::mk_param(tcx, i, ast_util::local_def(id))
})
}
/// 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(ctxt);
impl TypeFolder for TypeNormalizer {
fn tcx(&self) -> ty::ctxt { let TypeNormalizer(c) = *self; c }
fn fold_ty(&mut self, t: ty::t) -> ty::t {
let normalized_opt = {
let normalized_cache = self.tcx().normalized_cache.borrow();
normalized_cache.get().find_copy(&t)
};
match normalized_opt {
Some(u) => {
return u;
}
None => {
let t_norm = ty_fold::super_fold_ty(self, t);
let mut normalized_cache = self.tcx()
.normalized_cache
.borrow_mut();
normalized_cache.get().insert(t, t_norm);
return t_norm;
}
}
}
fn fold_vstore(&mut self, vstore: vstore) -> vstore {
match vstore {
vstore_fixed(..) | vstore_uniq => vstore,
vstore_slice(_) => vstore_slice(ReStatic)
}
}
fn fold_region(&mut self, _: ty::Region) -> ty::Region {
ty::ReStatic
}
fn fold_substs(&mut self,
substs: &substs)
-> substs {
substs { regions: ErasedRegions,
self_ty: ty_fold::fold_opt_ty(self, substs.self_ty),
tps: ty_fold::fold_ty_vec(self, substs.tps.as_slice()) }
}
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: ty_fold::fold_ty_vec(self, sig.inputs.as_slice()),
output: self.fold_ty(sig.output),
variadic: sig.variadic,
}
}
}
}
pub trait ExprTyProvider {
fn expr_ty(&self, ex: &ast::Expr) -> t;
fn ty_ctxt(&self) -> ctxt;
}
impl ExprTyProvider for ctxt {
fn expr_ty(&self, ex: &ast::Expr) -> t {
expr_ty(*self, ex)
}
fn ty_ctxt(&self) -> 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 but 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 but 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 but found string");
return 0;
}
const_eval::const_bool(_) => {
tcx.ty_ctxt().sess.span_err(count_expr.span,
"expected positive integer for \
repeat count but found boolean");
return 0;
}
const_eval::const_binary(_) => {
tcx.ty_ctxt().sess.span_err(count_expr.span,
"expected positive integer for \
repeat count but found binary array");
return 0;
}
},
Err(..) => {
tcx.ty_ctxt().sess.span_err(count_expr.span,
"expected constant integer for repeat count \
but found variable");
return 0;
}
}
}
// Determine what purity to check a nested function under
pub fn determine_inherited_purity(parent: (ast::Purity, ast::NodeId),
child: (ast::Purity, ast::NodeId),
child_sigil: ast::Sigil)
-> (ast::Purity, ast::NodeId) {
// If the closure is a stack closure and hasn't had some non-standard
// purity inferred for it, then check it under its parent's purity.
// Otherwise, use its own
match child_sigil {
ast::BorrowedSigil if child.val0() == ast::ImpureFn => parent,
_ => child
}
}
// 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: &[@TraitRef],
f: |@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);
// 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)) {
return false;
}
// Add supertraits to supertrait_set
let supertrait_refs = trait_ref_supertraits(tcx,
*trait_refs.get(i));
for &supertrait_ref in supertrait_refs.iter() {
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);
}
}
i += 1;
}
}
return true;
}
pub fn count_traits_and_supertraits(tcx: ctxt,
type_param_defs: &[TypeParameterDef]) -> uint {
let mut total = 0;
for type_param_def in type_param_defs.iter() {
each_bound_trait_and_supertraits(
tcx, type_param_def.bounds.trait_bounds.as_slice(), |_| {
total += 1;
true
});
}
return total;
}
pub fn get_tydesc_ty(tcx: ctxt) -> Result<t, ~str> {
tcx.lang_items.require(TyDescStructLangItem).map(|tydesc_lang_item| {
let intrinsic_defs = tcx.intrinsic_defs.borrow();
intrinsic_defs.get().find_copy(&tydesc_lang_item)
.expect("Failed to resolve TyDesc")
})
}
pub fn get_opaque_ty(tcx: ctxt) -> Result<t, ~str> {
tcx.lang_items.require(OpaqueStructLangItem).map(|opaque_lang_item| {
let intrinsic_defs = tcx.intrinsic_defs.borrow();
intrinsic_defs.get().find_copy(&opaque_lang_item)
.expect("Failed to resolve Opaque")
})
}
pub fn visitor_object_ty(tcx: ctxt,
region: ty::Region) -> Result<(@TraitRef, t), ~str> {
let trait_lang_item = match tcx.lang_items.require(TyVisitorTraitLangItem) {
Ok(id) => id,
Err(s) => { return Err(s); }
};
let substs = substs {
regions: ty::NonerasedRegions(opt_vec::Empty),
self_ty: None,
tps: Vec::new()
};
let trait_ref = @TraitRef { def_id: trait_lang_item, substs: substs };
Ok((trait_ref,
mk_trait(tcx,
trait_ref.def_id,
trait_ref.substs.clone(),
RegionTraitStore(region),
ast::MutMutable,
EmptyBuiltinBounds())))
}
pub fn item_variances(tcx: ctxt, item_id: ast::DefId) -> @ItemVariances {
let mut item_variance_map = tcx.item_variance_map.borrow_mut();
lookup_locally_or_in_crate_store(
"item_variance_map", item_id, item_variance_map.get(),
|| @csearch::get_item_variances(tcx.cstore, item_id))
}
/// Records a trait-to-implementation mapping.
fn record_trait_implementation(tcx: ctxt,
trait_def_id: DefId,
implementation: @Impl) {
let implementation_list;
let mut trait_impls = tcx.trait_impls.borrow_mut();
match trait_impls.get().find(&trait_def_id) {
None => {
implementation_list = @RefCell::new(Vec::new());
trait_impls.get().insert(trait_def_id, implementation_list);
}
Some(&existing_implementation_list) => {
implementation_list = existing_implementation_list
}
}
let mut implementation_list = implementation_list.borrow_mut();
implementation_list.get().push(implementation);
}
/// 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
}
{
let populated_external_types = tcx.populated_external_types.borrow();
if populated_external_types.get().contains(&type_id) {
return
}
}
csearch::each_implementation_for_type(tcx.sess.cstore, type_id,
|implementation_def_id| {
let implementation = @csearch::get_impl(tcx, implementation_def_id);
// Record the trait->implementation mappings, if applicable.
let associated_traits = csearch::get_impl_trait(tcx,
implementation.did);
for trait_ref in associated_traits.iter() {
record_trait_implementation(tcx,
trait_ref.def_id,
implementation);
}
// For any methods that use a default implementation, add them to
// the map. This is a bit unfortunate.
for method in implementation.methods.iter() {
for source in method.provided_source.iter() {
let mut provided_method_sources =
tcx.provided_method_sources.borrow_mut();
provided_method_sources.get().insert(method.def_id, *source);
}
}
// If this is an inherent implementation, record it.
if associated_traits.is_none() {
let implementation_list;
let mut inherent_impls = tcx.inherent_impls.borrow_mut();
match inherent_impls.get().find(&type_id) {
None => {
implementation_list = @RefCell::new(Vec::new());
inherent_impls.get().insert(type_id, implementation_list);
}
Some(&existing_implementation_list) => {
implementation_list = existing_implementation_list;
}
}
{
let mut implementation_list =
implementation_list.borrow_mut();
implementation_list.get().push(implementation);
}
}
// Store the implementation info.
let mut impls = tcx.impls.borrow_mut();
impls.get().insert(implementation_def_id, implementation);
});
let mut populated_external_types = tcx.populated_external_types
.borrow_mut();
populated_external_types.get().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
}
{
let populated_external_traits = tcx.populated_external_traits
.borrow();
if populated_external_traits.get().contains(&trait_id) {
return
}
}
csearch::each_implementation_for_trait(tcx.sess.cstore, trait_id,
|implementation_def_id| {
let implementation = @csearch::get_impl(tcx, implementation_def_id);
// Record the trait->implementation mapping.
record_trait_implementation(tcx, trait_id, implementation);
// For any methods that use a default implementation, add them to
// the map. This is a bit unfortunate.
for method in implementation.methods.iter() {
for source in method.provided_source.iter() {
let mut provided_method_sources =
tcx.provided_method_sources.borrow_mut();
provided_method_sources.get().insert(method.def_id, *source);
}
}
// Store the implementation info.
let mut impls = tcx.impls.borrow_mut();
impls.get().insert(implementation_def_id, implementation);
});
let mut populated_external_traits = tcx.populated_external_traits
.borrow_mut();
populated_external_traits.get().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 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_method(tcx: ctxt, def_id: ast::DefId)
-> Option<ast::DefId> {
if def_id.krate != LOCAL_CRATE {
return csearch::get_trait_of_method(tcx.cstore, def_id, tcx);
}
let method;
{
let methods = tcx.methods.borrow();
method = methods.get().find(&def_id).map(|method| *method);
}
match method {
Some(method) => {
match method.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 a method 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_method_of_method(tcx: ctxt,
def_id: ast::DefId) -> Option<ast::DefId> {
let method;
{
let methods = tcx.methods.borrow();
match methods.get().find(&def_id) {
Some(m) => method = *m,
None => return None,
}
}
let name = method.ident.name;
match trait_of_method(tcx, def_id) {
Some(trait_did) => {
let trait_methods = ty::trait_methods(tcx, trait_did);
trait_methods.iter()
.position(|m| m.ident.name == name)
.map(|idx| ty::trait_method(tcx, trait_did, idx).def_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 vstore = |state: &mut sip::SipState, v: vstore| {
match v {
vstore_fixed(_) => 0u8.hash(state),
vstore_uniq => 1u8.hash(state),
vstore_slice(r) => {
2u8.hash(state);
region(state, r);
}
}
};
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(v) => {
byte!(7);
hash!(v);
}
ty_enum(d, _) => {
byte!(8);
hash!(d)
}
ty_box(_) => {
byte!(9);
}
ty_uniq(_) => {
byte!(10);
}
ty_vec(m, v) => {
byte!(11);
mt(&mut state, m);
vstore(&mut state, v);
}
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.purity);
hash!(b.abis);
}
ty_closure(ref c) => {
byte!(15);
hash!(c.purity);
hash!(c.sigil);
hash!(c.onceness);
hash!(c.bounds);
region(&mut state, c.region);
}
ty_trait(d, _, store, m, bounds) => {
byte!(17);
did(&mut state, d);
match store {
UniqTraitStore => byte!(0),
RegionTraitStore(r) => {
byte!(1)
region(&mut state, r);
}
}
hash!(m);
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_self(d) => {
byte!(21);
did(&mut state, d);
}
ty_infer(_) => unreachable!(),
ty_err => byte!(23),
ty_unboxed_vec(m) => {
byte!(24);
mt(&mut state, m);
}
}
});
state.result()
}
impl Variance {
pub fn to_str(self) -> &'static str {
match self {
Covariant => "+",
Contravariant => "-",
Invariant => "o",
Bivariant => "*",
}
}
}
pub fn construct_parameter_environment(
tcx: ctxt,
self_bound: Option<@TraitRef>,
item_type_params: &[TypeParameterDef],
method_type_params: &[TypeParameterDef],
item_region_params: &[RegionParameterDef],
free_id: ast::NodeId)
-> ParameterEnvironment
{
/*! See `ParameterEnvironment` struct def'n for details */
//
// Construct the free substs.
//
// map Self => Self
let self_ty = self_bound.map(|t| ty::mk_self(tcx, t.def_id));
// map A => A
let num_item_type_params = item_type_params.len();
let num_method_type_params = method_type_params.len();
let num_type_params = num_item_type_params + num_method_type_params;
let type_params = Vec::from_fn(num_type_params, |i| {
let def_id = if i < num_item_type_params {
item_type_params[i].def_id
} else {
method_type_params[i - num_item_type_params].def_id
};
ty::mk_param(tcx, i, def_id)
});
// map bound 'a => free 'a
let region_params = item_region_params.iter().
map(|r| ty::ReFree(ty::FreeRegion {
scope_id: free_id,
bound_region: ty::BrNamed(r.def_id, r.ident)})).
collect();
let free_substs = substs {
self_ty: self_ty,
tps: type_params,
regions: ty::NonerasedRegions(region_params)
};
//
// Compute the bounds on Self and the type parameters.
//
let self_bound_substd = self_bound.map(|b| b.subst(tcx, &free_substs));
let type_param_bounds_substd = Vec::from_fn(num_type_params, |i| {
if i < num_item_type_params {
(*item_type_params[i].bounds).subst(tcx, &free_substs)
} else {
let j = i - num_item_type_params;
(*method_type_params[j].bounds).subst(tcx, &free_substs)
}
});
ty::ParameterEnvironment {
free_substs: free_substs,
self_param_bound: self_bound_substd,
type_param_bounds: type_param_bounds_substd,
}
}
impl substs {
pub fn empty() -> substs {
substs {
self_ty: None,
tps: Vec::new(),
regions: NonerasedRegions(opt_vec::Empty)
}
}
}
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",
}
}
pub fn to_short_str(&self) -> &'static str {
match *self {
MutBorrow => "mut",
ImmBorrow => "imm",
UniqueImmBorrow => "own",
}
}
}