rust/src/librustc_metadata/tyencode.rs
2016-05-11 04:14:58 +03:00

503 lines
16 KiB
Rust

// Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <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.
// Type encoding
#![allow(unused_must_use)] // as with encoding, everything is a no-fail MemWriter
#![allow(non_camel_case_types)]
use std::cell::RefCell;
use std::io::Cursor;
use std::io::prelude::*;
use rustc::hir::def_id::DefId;
use middle::region;
use rustc::ty::subst;
use rustc::ty::subst::VecPerParamSpace;
use rustc::ty::ParamTy;
use rustc::ty::{self, Ty, TyCtxt};
use rustc::util::nodemap::FnvHashMap;
use rustc::hir;
use syntax::abi::Abi;
use syntax::ast;
use syntax::errors::Handler;
use rbml::leb128;
use encoder;
pub struct ctxt<'a, 'tcx: 'a> {
pub diag: &'a Handler,
// Def -> str Callback:
pub ds: for<'b> fn(TyCtxt<'b, 'tcx, 'tcx>, DefId) -> String,
// The type context.
pub tcx: TyCtxt<'a, 'tcx, 'tcx>,
pub abbrevs: &'a abbrev_map<'tcx>
}
impl<'a, 'tcx> encoder::EncodeContext<'a, 'tcx> {
pub fn ty_str_ctxt<'b>(&'b self) -> ctxt<'b, 'tcx> {
ctxt {
diag: self.tcx.sess.diagnostic(),
ds: encoder::def_to_string,
tcx: self.tcx,
abbrevs: &self.type_abbrevs
}
}
}
// Compact string representation for Ty values. API TyStr & parse_from_str.
// Extra parameters are for converting to/from def_ids in the string rep.
// Whatever format you choose should not contain pipe characters.
pub struct ty_abbrev {
s: Vec<u8>
}
pub type abbrev_map<'tcx> = RefCell<FnvHashMap<Ty<'tcx>, ty_abbrev>>;
pub fn enc_ty<'a, 'tcx>(w: &mut Cursor<Vec<u8>>, cx: &ctxt<'a, 'tcx>, t: Ty<'tcx>) {
match cx.abbrevs.borrow_mut().get(&t) {
Some(a) => { w.write_all(&a.s); return; }
None => {}
}
let pos = w.position();
match t.sty {
ty::TyBool => { write!(w, "b"); }
ty::TyChar => { write!(w, "c"); }
ty::TyInt(t) => {
match t {
ast::IntTy::Is => write!(w, "is"),
ast::IntTy::I8 => write!(w, "MB"),
ast::IntTy::I16 => write!(w, "MW"),
ast::IntTy::I32 => write!(w, "ML"),
ast::IntTy::I64 => write!(w, "MD")
};
}
ty::TyUint(t) => {
match t {
ast::UintTy::Us => write!(w, "us"),
ast::UintTy::U8 => write!(w, "Mb"),
ast::UintTy::U16 => write!(w, "Mw"),
ast::UintTy::U32 => write!(w, "Ml"),
ast::UintTy::U64 => write!(w, "Md")
};
}
ty::TyFloat(t) => {
match t {
ast::FloatTy::F32 => write!(w, "Mf"),
ast::FloatTy::F64 => write!(w, "MF"),
};
}
ty::TyEnum(def, substs) => {
write!(w, "t[{}|", (cx.ds)(cx.tcx, def.did));
enc_substs(w, cx, substs);
write!(w, "]");
}
ty::TyTrait(box ty::TraitTy { ref principal,
ref bounds }) => {
write!(w, "x[");
enc_trait_ref(w, cx, principal.0);
enc_existential_bounds(w, cx, bounds);
write!(w, "]");
}
ty::TyTuple(ts) => {
write!(w, "T[");
for t in ts { enc_ty(w, cx, *t); }
write!(w, "]");
}
ty::TyBox(typ) => { write!(w, "~"); enc_ty(w, cx, typ); }
ty::TyRawPtr(mt) => { write!(w, "*"); enc_mt(w, cx, mt); }
ty::TyRef(r, mt) => {
write!(w, "&");
enc_region(w, cx, *r);
enc_mt(w, cx, mt);
}
ty::TyArray(t, sz) => {
write!(w, "V");
enc_ty(w, cx, t);
write!(w, "/{}|", sz);
}
ty::TySlice(t) => {
write!(w, "V");
enc_ty(w, cx, t);
write!(w, "/|");
}
ty::TyStr => {
write!(w, "v");
}
ty::TyFnDef(def_id, substs, f) => {
write!(w, "F");
write!(w, "{}|", (cx.ds)(cx.tcx, def_id));
enc_substs(w, cx, substs);
enc_bare_fn_ty(w, cx, f);
}
ty::TyFnPtr(f) => {
write!(w, "G");
enc_bare_fn_ty(w, cx, f);
}
ty::TyInfer(_) => {
bug!("cannot encode inference variable types");
}
ty::TyParam(ParamTy {space, idx, name}) => {
write!(w, "p[{}|{}|{}]", idx, space.to_uint(), name);
}
ty::TyStruct(def, substs) => {
write!(w, "a[{}|", (cx.ds)(cx.tcx, def.did));
enc_substs(w, cx, substs);
write!(w, "]");
}
ty::TyClosure(def, substs) => {
write!(w, "k[{}|", (cx.ds)(cx.tcx, def));
enc_substs(w, cx, substs.func_substs);
for ty in substs.upvar_tys {
enc_ty(w, cx, ty);
}
write!(w, ".");
write!(w, "]");
}
ty::TyProjection(ref data) => {
write!(w, "P[");
enc_trait_ref(w, cx, data.trait_ref);
write!(w, "{}]", data.item_name);
}
ty::TyError => {
write!(w, "e");
}
}
let end = w.position();
let len = end - pos;
let mut abbrev = Cursor::new(Vec::with_capacity(16));
abbrev.write_all(b"#");
{
let start_position = abbrev.position() as usize;
let bytes_written = leb128::write_unsigned_leb128(abbrev.get_mut(),
start_position,
pos);
abbrev.set_position((start_position + bytes_written) as u64);
}
cx.abbrevs.borrow_mut().insert(t, ty_abbrev {
s: if abbrev.position() < len {
abbrev.get_ref()[..abbrev.position() as usize].to_owned()
} else {
// if the abbreviation is longer than the real type,
// don't use #-notation. However, insert it here so
// other won't have to `mark_stable_position`
w.get_ref()[pos as usize .. end as usize].to_owned()
}
});
}
fn enc_mutability(w: &mut Cursor<Vec<u8>>, mt: hir::Mutability) {
match mt {
hir::MutImmutable => (),
hir::MutMutable => {
write!(w, "m");
}
};
}
fn enc_mt<'a, 'tcx>(w: &mut Cursor<Vec<u8>>, cx: &ctxt<'a, 'tcx>,
mt: ty::TypeAndMut<'tcx>) {
enc_mutability(w, mt.mutbl);
enc_ty(w, cx, mt.ty);
}
fn enc_opt<T, F>(w: &mut Cursor<Vec<u8>>, t: Option<T>, enc_f: F) where
F: FnOnce(&mut Cursor<Vec<u8>>, T),
{
match t {
None => {
write!(w, "n");
}
Some(v) => {
write!(w, "s");
enc_f(w, v);
}
}
}
fn enc_vec_per_param_space<'a, 'tcx, T, F>(w: &mut Cursor<Vec<u8>>,
cx: &ctxt<'a, 'tcx>,
v: &VecPerParamSpace<T>,
mut op: F) where
F: FnMut(&mut Cursor<Vec<u8>>, &ctxt<'a, 'tcx>, &T),
{
for &space in &subst::ParamSpace::all() {
write!(w, "[");
for t in v.get_slice(space) {
op(w, cx, t);
}
write!(w, "]");
}
}
pub fn enc_substs<'a, 'tcx>(w: &mut Cursor<Vec<u8>>, cx: &ctxt<'a, 'tcx>,
substs: &subst::Substs<'tcx>) {
enc_vec_per_param_space(w, cx, &substs.regions,
|w, cx, &r| enc_region(w, cx, r));
enc_vec_per_param_space(w, cx, &substs.types,
|w, cx, &ty| enc_ty(w, cx, ty));
}
pub fn enc_region(w: &mut Cursor<Vec<u8>>, cx: &ctxt, r: ty::Region) {
match r {
ty::ReLateBound(id, br) => {
write!(w, "b[{}|", id.depth);
enc_bound_region(w, cx, br);
write!(w, "]");
}
ty::ReEarlyBound(ref data) => {
write!(w, "B[{}|{}|{}]",
data.space.to_uint(),
data.index,
data.name);
}
ty::ReFree(ref fr) => {
write!(w, "f[");
enc_scope(w, cx, fr.scope);
write!(w, "|");
enc_bound_region(w, cx, fr.bound_region);
write!(w, "]");
}
ty::ReScope(scope) => {
write!(w, "s");
enc_scope(w, cx, scope);
write!(w, "|");
}
ty::ReStatic => {
write!(w, "t");
}
ty::ReEmpty => {
write!(w, "e");
}
ty::ReVar(_) | ty::ReSkolemized(..) => {
// these should not crop up after typeck
bug!("cannot encode region variables");
}
}
}
fn enc_scope(w: &mut Cursor<Vec<u8>>, cx: &ctxt, scope: region::CodeExtent) {
match cx.tcx.region_maps.code_extent_data(scope) {
region::CodeExtentData::CallSiteScope {
fn_id, body_id } => write!(w, "C[{}|{}]", fn_id, body_id),
region::CodeExtentData::ParameterScope {
fn_id, body_id } => write!(w, "P[{}|{}]", fn_id, body_id),
region::CodeExtentData::Misc(node_id) => write!(w, "M{}", node_id),
region::CodeExtentData::Remainder(region::BlockRemainder {
block: b, first_statement_index: i }) => write!(w, "B[{}|{}]", b, i),
region::CodeExtentData::DestructionScope(node_id) => write!(w, "D{}", node_id),
};
}
fn enc_bound_region(w: &mut Cursor<Vec<u8>>, cx: &ctxt, br: ty::BoundRegion) {
match br {
ty::BrAnon(idx) => {
write!(w, "a{}|", idx);
}
ty::BrNamed(d, name) => {
write!(w, "[{}|{}]",
(cx.ds)(cx.tcx, d),
name);
}
ty::BrFresh(id) => {
write!(w, "f{}|", id);
}
ty::BrEnv => {
write!(w, "e|");
}
}
}
pub fn enc_trait_ref<'a, 'tcx>(w: &mut Cursor<Vec<u8>>, cx: &ctxt<'a, 'tcx>,
s: ty::TraitRef<'tcx>) {
write!(w, "{}|", (cx.ds)(cx.tcx, s.def_id));
enc_substs(w, cx, s.substs);
}
fn enc_unsafety(w: &mut Cursor<Vec<u8>>, p: hir::Unsafety) {
match p {
hir::Unsafety::Normal => write!(w, "n"),
hir::Unsafety::Unsafe => write!(w, "u"),
};
}
fn enc_abi(w: &mut Cursor<Vec<u8>>, abi: Abi) {
write!(w, "[");
write!(w, "{}", abi.name());
write!(w, "]");
}
pub fn enc_bare_fn_ty<'a, 'tcx>(w: &mut Cursor<Vec<u8>>, cx: &ctxt<'a, 'tcx>,
ft: &ty::BareFnTy<'tcx>) {
enc_unsafety(w, ft.unsafety);
enc_abi(w, ft.abi);
enc_fn_sig(w, cx, &ft.sig);
}
pub fn enc_closure_ty<'a, 'tcx>(w: &mut Cursor<Vec<u8>>, cx: &ctxt<'a, 'tcx>,
ft: &ty::ClosureTy<'tcx>) {
enc_unsafety(w, ft.unsafety);
enc_fn_sig(w, cx, &ft.sig);
enc_abi(w, ft.abi);
}
fn enc_fn_sig<'a, 'tcx>(w: &mut Cursor<Vec<u8>>, cx: &ctxt<'a, 'tcx>,
fsig: &ty::PolyFnSig<'tcx>) {
write!(w, "[");
for ty in &fsig.0.inputs {
enc_ty(w, cx, *ty);
}
write!(w, "]");
if fsig.0.variadic {
write!(w, "V");
} else {
write!(w, "N");
}
match fsig.0.output {
ty::FnConverging(result_type) => {
enc_ty(w, cx, result_type);
}
ty::FnDiverging => {
write!(w, "z");
}
}
}
pub fn enc_builtin_bounds(w: &mut Cursor<Vec<u8>>, _cx: &ctxt, bs: &ty::BuiltinBounds) {
for bound in bs {
match bound {
ty::BoundSend => write!(w, "S"),
ty::BoundSized => write!(w, "Z"),
ty::BoundCopy => write!(w, "P"),
ty::BoundSync => write!(w, "T"),
};
}
write!(w, ".");
}
pub fn enc_existential_bounds<'a,'tcx>(w: &mut Cursor<Vec<u8>>,
cx: &ctxt<'a,'tcx>,
bs: &ty::ExistentialBounds<'tcx>) {
enc_builtin_bounds(w, cx, &bs.builtin_bounds);
enc_region(w, cx, bs.region_bound);
for tp in &bs.projection_bounds {
write!(w, "P");
enc_projection_predicate(w, cx, &tp.0);
}
write!(w, ".");
}
pub fn enc_type_param_def<'a, 'tcx>(w: &mut Cursor<Vec<u8>>, cx: &ctxt<'a, 'tcx>,
v: &ty::TypeParameterDef<'tcx>) {
write!(w, "{}:{}|{}|{}|{}|",
v.name, (cx.ds)(cx.tcx, v.def_id),
v.space.to_uint(), v.index, (cx.ds)(cx.tcx, v.default_def_id));
enc_opt(w, v.default, |w, t| enc_ty(w, cx, t));
enc_object_lifetime_default(w, cx, v.object_lifetime_default);
}
pub fn enc_region_param_def(w: &mut Cursor<Vec<u8>>, cx: &ctxt,
v: &ty::RegionParameterDef) {
write!(w, "{}:{}|{}|{}|",
v.name, (cx.ds)(cx.tcx, v.def_id),
v.space.to_uint(), v.index);
for &r in &v.bounds {
write!(w, "R");
enc_region(w, cx, r);
}
write!(w, ".");
}
fn enc_object_lifetime_default<'a, 'tcx>(w: &mut Cursor<Vec<u8>>,
cx: &ctxt<'a, 'tcx>,
default: ty::ObjectLifetimeDefault)
{
match default {
ty::ObjectLifetimeDefault::Ambiguous => {
write!(w, "a");
}
ty::ObjectLifetimeDefault::BaseDefault => {
write!(w, "b");
}
ty::ObjectLifetimeDefault::Specific(r) => {
write!(w, "s");
enc_region(w, cx, r);
}
}
}
pub fn enc_predicate<'a, 'tcx>(w: &mut Cursor<Vec<u8>>,
cx: &ctxt<'a, 'tcx>,
p: &ty::Predicate<'tcx>)
{
match *p {
ty::Predicate::Rfc1592(..) => {
bug!("RFC1592 predicate in metadata `{:?}`", p);
}
ty::Predicate::Trait(ref trait_ref) => {
write!(w, "t");
enc_trait_ref(w, cx, trait_ref.0.trait_ref);
}
ty::Predicate::Equate(ty::Binder(ty::EquatePredicate(a, b))) => {
write!(w, "e");
enc_ty(w, cx, a);
enc_ty(w, cx, b);
}
ty::Predicate::RegionOutlives(ty::Binder(ty::OutlivesPredicate(a, b))) => {
write!(w, "r");
enc_region(w, cx, a);
enc_region(w, cx, b);
}
ty::Predicate::TypeOutlives(ty::Binder(ty::OutlivesPredicate(a, b))) => {
write!(w, "o");
enc_ty(w, cx, a);
enc_region(w, cx, b);
}
ty::Predicate::Projection(ty::Binder(ref data)) => {
write!(w, "p");
enc_projection_predicate(w, cx, data);
}
ty::Predicate::WellFormed(data) => {
write!(w, "w");
enc_ty(w, cx, data);
}
ty::Predicate::ObjectSafe(trait_def_id) => {
write!(w, "O{}|", (cx.ds)(cx.tcx, trait_def_id));
}
ty::Predicate::ClosureKind(closure_def_id, kind) => {
let kind_char = match kind {
ty::ClosureKind::Fn => 'f',
ty::ClosureKind::FnMut => 'm',
ty::ClosureKind::FnOnce => 'o',
};
write!(w, "c{}|{}|", (cx.ds)(cx.tcx, closure_def_id), kind_char);
}
}
}
fn enc_projection_predicate<'a, 'tcx>(w: &mut Cursor<Vec<u8>>,
cx: &ctxt<'a, 'tcx>,
data: &ty::ProjectionPredicate<'tcx>) {
enc_trait_ref(w, cx, data.projection_ty.trait_ref);
write!(w, "{}|", data.projection_ty.item_name);
enc_ty(w, cx, data.ty);
}