1 //! This module contains some shared code for encoding and decoding various
2 //! things from the `ty` module, and in particular implements support for
3 //! "shorthands" which allow to have pointers back into the already encoded
4 //! stream instead of re-encoding the same thing twice.
5 //!
6 //! The functionality in here is shared between persisting to crate metadata and
7 //! persisting to incr. comp. caches.
8
9 use crate::arena::ArenaAllocatable;
10 use crate::infer::canonical::{CanonicalVarInfo, CanonicalVarInfos};
11 use crate::mir::{
12 self,
13 interpret::{AllocId, Allocation},
14 };
15 use crate::thir;
16 use crate::ty::subst::SubstsRef;
17 use crate::ty::{self, List, Ty, TyCtxt};
18 use rustc_data_structures::fx::FxHashMap;
19 use rustc_hir::def_id::DefId;
20 use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
21 use rustc_span::Span;
22 use std::hash::Hash;
23 use std::intrinsics;
24 use std::marker::DiscriminantKind;
25
26 /// The shorthand encoding uses an enum's variant index `usize`
27 /// and is offset by this value so it never matches a real variant.
28 /// This offset is also chosen so that the first byte is never < 0x80.
29 pub const SHORTHAND_OFFSET: usize = 0x80;
30
31 pub trait EncodableWithShorthand<'tcx, E: TyEncoder<'tcx>>: Copy + Eq + Hash {
32 type Variant: Encodable<E>;
variant(&self) -> &Self::Variant33 fn variant(&self) -> &Self::Variant;
34 }
35
36 #[allow(rustc::usage_of_ty_tykind)]
37 impl<'tcx, E: TyEncoder<'tcx>> EncodableWithShorthand<'tcx, E> for Ty<'tcx> {
38 type Variant = ty::TyKind<'tcx>;
39
40 #[inline]
variant(&self) -> &Self::Variant41 fn variant(&self) -> &Self::Variant {
42 self.kind()
43 }
44 }
45
46 impl<'tcx, E: TyEncoder<'tcx>> EncodableWithShorthand<'tcx, E> for ty::PredicateKind<'tcx> {
47 type Variant = ty::PredicateKind<'tcx>;
48
49 #[inline]
variant(&self) -> &Self::Variant50 fn variant(&self) -> &Self::Variant {
51 self
52 }
53 }
54
55 pub trait TyEncoder<'tcx>: Encoder {
56 const CLEAR_CROSS_CRATE: bool;
57
position(&self) -> usize58 fn position(&self) -> usize;
type_shorthands(&mut self) -> &mut FxHashMap<Ty<'tcx>, usize>59 fn type_shorthands(&mut self) -> &mut FxHashMap<Ty<'tcx>, usize>;
predicate_shorthands(&mut self) -> &mut FxHashMap<ty::PredicateKind<'tcx>, usize>60 fn predicate_shorthands(&mut self) -> &mut FxHashMap<ty::PredicateKind<'tcx>, usize>;
encode_alloc_id(&mut self, alloc_id: &AllocId) -> Result<(), Self::Error>61 fn encode_alloc_id(&mut self, alloc_id: &AllocId) -> Result<(), Self::Error>;
62 }
63
64 /// Trait for decoding to a reference.
65 ///
66 /// This is a separate trait from `Decodable` so that we can implement it for
67 /// upstream types, such as `FxHashSet`.
68 ///
69 /// The `TyDecodable` derive macro will use this trait for fields that are
70 /// references (and don't use a type alias to hide that).
71 ///
72 /// `Decodable` can still be implemented in cases where `Decodable` is required
73 /// by a trait bound.
74 pub trait RefDecodable<'tcx, D: TyDecoder<'tcx>> {
decode(d: &mut D) -> Result<&'tcx Self, D::Error>75 fn decode(d: &mut D) -> Result<&'tcx Self, D::Error>;
76 }
77
78 /// Encode the given value or a previously cached shorthand.
encode_with_shorthand<E, T, M>(encoder: &mut E, value: &T, cache: M) -> Result<(), E::Error> where E: TyEncoder<'tcx>, M: for<'b> Fn(&'b mut E) -> &'b mut FxHashMap<T, usize>, T: EncodableWithShorthand<'tcx, E>, T::Variant: DiscriminantKind<Discriminant = isize>,79 pub fn encode_with_shorthand<E, T, M>(encoder: &mut E, value: &T, cache: M) -> Result<(), E::Error>
80 where
81 E: TyEncoder<'tcx>,
82 M: for<'b> Fn(&'b mut E) -> &'b mut FxHashMap<T, usize>,
83 T: EncodableWithShorthand<'tcx, E>,
84 // The discriminant and shorthand must have the same size.
85 T::Variant: DiscriminantKind<Discriminant = isize>,
86 {
87 let existing_shorthand = cache(encoder).get(value).copied();
88 if let Some(shorthand) = existing_shorthand {
89 return encoder.emit_usize(shorthand);
90 }
91
92 let variant = value.variant();
93
94 let start = encoder.position();
95 variant.encode(encoder)?;
96 let len = encoder.position() - start;
97
98 // The shorthand encoding uses the same usize as the
99 // discriminant, with an offset so they can't conflict.
100 let discriminant = intrinsics::discriminant_value(variant);
101 assert!(SHORTHAND_OFFSET > discriminant as usize);
102
103 let shorthand = start + SHORTHAND_OFFSET;
104
105 // Get the number of bits that leb128 could fit
106 // in the same space as the fully encoded type.
107 let leb128_bits = len * 7;
108
109 // Check that the shorthand is a not longer than the
110 // full encoding itself, i.e., it's an obvious win.
111 if leb128_bits >= 64 || (shorthand as u64) < (1 << leb128_bits) {
112 cache(encoder).insert(*value, shorthand);
113 }
114
115 Ok(())
116 }
117
118 impl<'tcx, E: TyEncoder<'tcx>> Encodable<E> for Ty<'tcx> {
encode(&self, e: &mut E) -> Result<(), E::Error>119 fn encode(&self, e: &mut E) -> Result<(), E::Error> {
120 encode_with_shorthand(e, self, TyEncoder::type_shorthands)
121 }
122 }
123
124 impl<'tcx, E: TyEncoder<'tcx>> Encodable<E> for ty::Binder<'tcx, ty::PredicateKind<'tcx>> {
encode(&self, e: &mut E) -> Result<(), E::Error>125 fn encode(&self, e: &mut E) -> Result<(), E::Error> {
126 self.bound_vars().encode(e)?;
127 encode_with_shorthand(e, &self.skip_binder(), TyEncoder::predicate_shorthands)
128 }
129 }
130
131 impl<'tcx, E: TyEncoder<'tcx>> Encodable<E> for ty::Predicate<'tcx> {
encode(&self, e: &mut E) -> Result<(), E::Error>132 fn encode(&self, e: &mut E) -> Result<(), E::Error> {
133 self.kind().encode(e)
134 }
135 }
136
137 impl<'tcx, E: TyEncoder<'tcx>> Encodable<E> for AllocId {
encode(&self, e: &mut E) -> Result<(), E::Error>138 fn encode(&self, e: &mut E) -> Result<(), E::Error> {
139 e.encode_alloc_id(self)
140 }
141 }
142
143 macro_rules! encodable_via_deref {
144 ($($t:ty),+) => {
145 $(impl<'tcx, E: TyEncoder<'tcx>> Encodable<E> for $t {
146 fn encode(&self, e: &mut E) -> Result<(), E::Error> {
147 (**self).encode(e)
148 }
149 })*
150 }
151 }
152
153 encodable_via_deref! {
154 &'tcx ty::TypeckResults<'tcx>,
155 ty::Region<'tcx>,
156 &'tcx mir::Body<'tcx>,
157 &'tcx mir::UnsafetyCheckResult,
158 &'tcx mir::BorrowCheckResult<'tcx>,
159 &'tcx mir::coverage::CodeRegion
160 }
161
162 pub trait TyDecoder<'tcx>: Decoder {
163 const CLEAR_CROSS_CRATE: bool;
164
tcx(&self) -> TyCtxt<'tcx>165 fn tcx(&self) -> TyCtxt<'tcx>;
166
peek_byte(&self) -> u8167 fn peek_byte(&self) -> u8;
168
position(&self) -> usize169 fn position(&self) -> usize;
170
cached_ty_for_shorthand<F>( &mut self, shorthand: usize, or_insert_with: F, ) -> Result<Ty<'tcx>, Self::Error> where F: FnOnce(&mut Self) -> Result<Ty<'tcx>, Self::Error>171 fn cached_ty_for_shorthand<F>(
172 &mut self,
173 shorthand: usize,
174 or_insert_with: F,
175 ) -> Result<Ty<'tcx>, Self::Error>
176 where
177 F: FnOnce(&mut Self) -> Result<Ty<'tcx>, Self::Error>;
178
with_position<F, R>(&mut self, pos: usize, f: F) -> R where F: FnOnce(&mut Self) -> R179 fn with_position<F, R>(&mut self, pos: usize, f: F) -> R
180 where
181 F: FnOnce(&mut Self) -> R;
182
positioned_at_shorthand(&self) -> bool183 fn positioned_at_shorthand(&self) -> bool {
184 (self.peek_byte() & (SHORTHAND_OFFSET as u8)) != 0
185 }
186
decode_alloc_id(&mut self) -> Result<AllocId, Self::Error>187 fn decode_alloc_id(&mut self) -> Result<AllocId, Self::Error>;
188 }
189
190 #[inline]
decode_arena_allocable<'tcx, D, T: ArenaAllocatable<'tcx> + Decodable<D>>( decoder: &mut D, ) -> Result<&'tcx T, D::Error> where D: TyDecoder<'tcx>,191 fn decode_arena_allocable<'tcx, D, T: ArenaAllocatable<'tcx> + Decodable<D>>(
192 decoder: &mut D,
193 ) -> Result<&'tcx T, D::Error>
194 where
195 D: TyDecoder<'tcx>,
196 {
197 Ok(decoder.tcx().arena.alloc(Decodable::decode(decoder)?))
198 }
199
200 #[inline]
decode_arena_allocable_slice<'tcx, D, T: ArenaAllocatable<'tcx> + Decodable<D>>( decoder: &mut D, ) -> Result<&'tcx [T], D::Error> where D: TyDecoder<'tcx>,201 fn decode_arena_allocable_slice<'tcx, D, T: ArenaAllocatable<'tcx> + Decodable<D>>(
202 decoder: &mut D,
203 ) -> Result<&'tcx [T], D::Error>
204 where
205 D: TyDecoder<'tcx>,
206 {
207 Ok(decoder.tcx().arena.alloc_from_iter(<Vec<T> as Decodable<D>>::decode(decoder)?))
208 }
209
210 impl<'tcx, D: TyDecoder<'tcx>> Decodable<D> for Ty<'tcx> {
211 #[allow(rustc::usage_of_ty_tykind)]
decode(decoder: &mut D) -> Result<Ty<'tcx>, D::Error>212 fn decode(decoder: &mut D) -> Result<Ty<'tcx>, D::Error> {
213 // Handle shorthands first, if we have a usize > 0x80.
214 if decoder.positioned_at_shorthand() {
215 let pos = decoder.read_usize()?;
216 assert!(pos >= SHORTHAND_OFFSET);
217 let shorthand = pos - SHORTHAND_OFFSET;
218
219 decoder.cached_ty_for_shorthand(shorthand, |decoder| {
220 decoder.with_position(shorthand, Ty::decode)
221 })
222 } else {
223 let tcx = decoder.tcx();
224 Ok(tcx.mk_ty(ty::TyKind::decode(decoder)?))
225 }
226 }
227 }
228
229 impl<'tcx, D: TyDecoder<'tcx>> Decodable<D> for ty::Binder<'tcx, ty::PredicateKind<'tcx>> {
decode(decoder: &mut D) -> Result<ty::Binder<'tcx, ty::PredicateKind<'tcx>>, D::Error>230 fn decode(decoder: &mut D) -> Result<ty::Binder<'tcx, ty::PredicateKind<'tcx>>, D::Error> {
231 let bound_vars = Decodable::decode(decoder)?;
232 // Handle shorthands first, if we have a usize > 0x80.
233 Ok(ty::Binder::bind_with_vars(
234 if decoder.positioned_at_shorthand() {
235 let pos = decoder.read_usize()?;
236 assert!(pos >= SHORTHAND_OFFSET);
237 let shorthand = pos - SHORTHAND_OFFSET;
238
239 decoder.with_position(shorthand, ty::PredicateKind::decode)?
240 } else {
241 ty::PredicateKind::decode(decoder)?
242 },
243 bound_vars,
244 ))
245 }
246 }
247
248 impl<'tcx, D: TyDecoder<'tcx>> Decodable<D> for ty::Predicate<'tcx> {
decode(decoder: &mut D) -> Result<ty::Predicate<'tcx>, D::Error>249 fn decode(decoder: &mut D) -> Result<ty::Predicate<'tcx>, D::Error> {
250 let predicate_kind = Decodable::decode(decoder)?;
251 let predicate = decoder.tcx().mk_predicate(predicate_kind);
252 Ok(predicate)
253 }
254 }
255
256 impl<'tcx, D: TyDecoder<'tcx>> Decodable<D> for SubstsRef<'tcx> {
decode(decoder: &mut D) -> Result<Self, D::Error>257 fn decode(decoder: &mut D) -> Result<Self, D::Error> {
258 let len = decoder.read_usize()?;
259 let tcx = decoder.tcx();
260 tcx.mk_substs((0..len).map(|_| Decodable::decode(decoder)))
261 }
262 }
263
264 impl<'tcx, D: TyDecoder<'tcx>> Decodable<D> for mir::Place<'tcx> {
decode(decoder: &mut D) -> Result<Self, D::Error>265 fn decode(decoder: &mut D) -> Result<Self, D::Error> {
266 let local: mir::Local = Decodable::decode(decoder)?;
267 let len = decoder.read_usize()?;
268 let projection: &'tcx List<mir::PlaceElem<'tcx>> =
269 decoder.tcx().mk_place_elems((0..len).map(|_| Decodable::decode(decoder)))?;
270 Ok(mir::Place { local, projection })
271 }
272 }
273
274 impl<'tcx, D: TyDecoder<'tcx>> Decodable<D> for ty::Region<'tcx> {
decode(decoder: &mut D) -> Result<Self, D::Error>275 fn decode(decoder: &mut D) -> Result<Self, D::Error> {
276 Ok(decoder.tcx().mk_region(Decodable::decode(decoder)?))
277 }
278 }
279
280 impl<'tcx, D: TyDecoder<'tcx>> Decodable<D> for CanonicalVarInfos<'tcx> {
decode(decoder: &mut D) -> Result<Self, D::Error>281 fn decode(decoder: &mut D) -> Result<Self, D::Error> {
282 let len = decoder.read_usize()?;
283 let interned: Result<Vec<CanonicalVarInfo<'tcx>>, _> =
284 (0..len).map(|_| Decodable::decode(decoder)).collect();
285 Ok(decoder.tcx().intern_canonical_var_infos(interned?.as_slice()))
286 }
287 }
288
289 impl<'tcx, D: TyDecoder<'tcx>> Decodable<D> for AllocId {
decode(decoder: &mut D) -> Result<Self, D::Error>290 fn decode(decoder: &mut D) -> Result<Self, D::Error> {
291 decoder.decode_alloc_id()
292 }
293 }
294
295 impl<'tcx, D: TyDecoder<'tcx>> Decodable<D> for ty::SymbolName<'tcx> {
decode(decoder: &mut D) -> Result<Self, D::Error>296 fn decode(decoder: &mut D) -> Result<Self, D::Error> {
297 Ok(ty::SymbolName::new(decoder.tcx(), &decoder.read_str()?))
298 }
299 }
300
301 macro_rules! impl_decodable_via_ref {
302 ($($t:ty),+) => {
303 $(impl<'tcx, D: TyDecoder<'tcx>> Decodable<D> for $t {
304 fn decode(decoder: &mut D) -> Result<Self, D::Error> {
305 RefDecodable::decode(decoder)
306 }
307 })*
308 }
309 }
310
311 impl<'tcx, D: TyDecoder<'tcx>> RefDecodable<'tcx, D> for ty::AdtDef {
decode(decoder: &mut D) -> Result<&'tcx Self, D::Error>312 fn decode(decoder: &mut D) -> Result<&'tcx Self, D::Error> {
313 let def_id = <DefId as Decodable<D>>::decode(decoder)?;
314 Ok(decoder.tcx().adt_def(def_id))
315 }
316 }
317
318 impl<'tcx, D: TyDecoder<'tcx>> RefDecodable<'tcx, D> for ty::List<Ty<'tcx>> {
decode(decoder: &mut D) -> Result<&'tcx Self, D::Error>319 fn decode(decoder: &mut D) -> Result<&'tcx Self, D::Error> {
320 let len = decoder.read_usize()?;
321 decoder.tcx().mk_type_list((0..len).map(|_| Decodable::decode(decoder)))
322 }
323 }
324
325 impl<'tcx, D: TyDecoder<'tcx>> RefDecodable<'tcx, D>
326 for ty::List<ty::Binder<'tcx, ty::ExistentialPredicate<'tcx>>>
327 {
decode(decoder: &mut D) -> Result<&'tcx Self, D::Error>328 fn decode(decoder: &mut D) -> Result<&'tcx Self, D::Error> {
329 let len = decoder.read_usize()?;
330 decoder.tcx().mk_poly_existential_predicates((0..len).map(|_| Decodable::decode(decoder)))
331 }
332 }
333
334 impl<'tcx, D: TyDecoder<'tcx>> RefDecodable<'tcx, D> for ty::Const<'tcx> {
decode(decoder: &mut D) -> Result<&'tcx Self, D::Error>335 fn decode(decoder: &mut D) -> Result<&'tcx Self, D::Error> {
336 Ok(decoder.tcx().mk_const(Decodable::decode(decoder)?))
337 }
338 }
339
340 impl<'tcx, D: TyDecoder<'tcx>> RefDecodable<'tcx, D> for [ty::ValTree<'tcx>] {
decode(decoder: &mut D) -> Result<&'tcx Self, D::Error>341 fn decode(decoder: &mut D) -> Result<&'tcx Self, D::Error> {
342 Ok(decoder.tcx().arena.alloc_from_iter(
343 (0..decoder.read_usize()?)
344 .map(|_| Decodable::decode(decoder))
345 .collect::<Result<Vec<_>, _>>()?,
346 ))
347 }
348 }
349
350 impl<'tcx, D: TyDecoder<'tcx>> RefDecodable<'tcx, D> for Allocation {
decode(decoder: &mut D) -> Result<&'tcx Self, D::Error>351 fn decode(decoder: &mut D) -> Result<&'tcx Self, D::Error> {
352 Ok(decoder.tcx().intern_const_alloc(Decodable::decode(decoder)?))
353 }
354 }
355
356 impl<'tcx, D: TyDecoder<'tcx>> RefDecodable<'tcx, D> for [(ty::Predicate<'tcx>, Span)] {
decode(decoder: &mut D) -> Result<&'tcx Self, D::Error>357 fn decode(decoder: &mut D) -> Result<&'tcx Self, D::Error> {
358 Ok(decoder.tcx().arena.alloc_from_iter(
359 (0..decoder.read_usize()?)
360 .map(|_| Decodable::decode(decoder))
361 .collect::<Result<Vec<_>, _>>()?,
362 ))
363 }
364 }
365
366 impl<'tcx, D: TyDecoder<'tcx>> RefDecodable<'tcx, D> for [thir::abstract_const::Node<'tcx>] {
decode(decoder: &mut D) -> Result<&'tcx Self, D::Error>367 fn decode(decoder: &mut D) -> Result<&'tcx Self, D::Error> {
368 Ok(decoder.tcx().arena.alloc_from_iter(
369 (0..decoder.read_usize()?)
370 .map(|_| Decodable::decode(decoder))
371 .collect::<Result<Vec<_>, _>>()?,
372 ))
373 }
374 }
375
376 impl<'tcx, D: TyDecoder<'tcx>> RefDecodable<'tcx, D> for [thir::abstract_const::NodeId] {
decode(decoder: &mut D) -> Result<&'tcx Self, D::Error>377 fn decode(decoder: &mut D) -> Result<&'tcx Self, D::Error> {
378 Ok(decoder.tcx().arena.alloc_from_iter(
379 (0..decoder.read_usize()?)
380 .map(|_| Decodable::decode(decoder))
381 .collect::<Result<Vec<_>, _>>()?,
382 ))
383 }
384 }
385
386 impl<'tcx, D: TyDecoder<'tcx>> RefDecodable<'tcx, D> for ty::List<ty::BoundVariableKind> {
decode(decoder: &mut D) -> Result<&'tcx Self, D::Error>387 fn decode(decoder: &mut D) -> Result<&'tcx Self, D::Error> {
388 let len = decoder.read_usize()?;
389 decoder.tcx().mk_bound_variable_kinds((0..len).map(|_| Decodable::decode(decoder)))
390 }
391 }
392
393 impl_decodable_via_ref! {
394 &'tcx ty::TypeckResults<'tcx>,
395 &'tcx ty::List<Ty<'tcx>>,
396 &'tcx ty::List<ty::Binder<'tcx, ty::ExistentialPredicate<'tcx>>>,
397 &'tcx Allocation,
398 &'tcx mir::Body<'tcx>,
399 &'tcx mir::UnsafetyCheckResult,
400 &'tcx mir::BorrowCheckResult<'tcx>,
401 &'tcx mir::coverage::CodeRegion,
402 &'tcx ty::List<ty::BoundVariableKind>
403 }
404
405 #[macro_export]
406 macro_rules! __impl_decoder_methods {
407 ($($name:ident -> $ty:ty;)*) => {
408 $(
409 #[inline]
410 fn $name(&mut self) -> Result<$ty, Self::Error> {
411 self.opaque.$name()
412 }
413 )*
414 }
415 }
416
417 macro_rules! impl_arena_allocatable_decoder {
418 ([]$args:tt) => {};
419 ([decode $(, $attrs:ident)*]
420 [$name:ident: $ty:ty]) => {
421 impl<'tcx, D: TyDecoder<'tcx>> RefDecodable<'tcx, D> for $ty {
422 #[inline]
423 fn decode(decoder: &mut D) -> Result<&'tcx Self, D::Error> {
424 decode_arena_allocable(decoder)
425 }
426 }
427
428 impl<'tcx, D: TyDecoder<'tcx>> RefDecodable<'tcx, D> for [$ty] {
429 #[inline]
430 fn decode(decoder: &mut D) -> Result<&'tcx Self, D::Error> {
431 decode_arena_allocable_slice(decoder)
432 }
433 }
434 };
435 ([$ignore:ident $(, $attrs:ident)*]$args:tt) => {
436 impl_arena_allocatable_decoder!([$($attrs),*]$args);
437 };
438 }
439
440 macro_rules! impl_arena_allocatable_decoders {
441 ([$($a:tt $name:ident: $ty:ty,)*]) => {
442 $(
443 impl_arena_allocatable_decoder!($a [$name: $ty]);
444 )*
445 }
446 }
447
448 rustc_hir::arena_types!(impl_arena_allocatable_decoders);
449 arena_types!(impl_arena_allocatable_decoders);
450
451 #[macro_export]
452 macro_rules! implement_ty_decoder {
453 ($DecoderName:ident <$($typaram:tt),*>) => {
454 mod __ty_decoder_impl {
455 use std::borrow::Cow;
456 use rustc_serialize::Decoder;
457
458 use super::$DecoderName;
459
460 impl<$($typaram ),*> Decoder for $DecoderName<$($typaram),*> {
461 type Error = String;
462
463 $crate::__impl_decoder_methods! {
464 read_nil -> ();
465
466 read_u128 -> u128;
467 read_u64 -> u64;
468 read_u32 -> u32;
469 read_u16 -> u16;
470 read_u8 -> u8;
471 read_usize -> usize;
472
473 read_i128 -> i128;
474 read_i64 -> i64;
475 read_i32 -> i32;
476 read_i16 -> i16;
477 read_i8 -> i8;
478 read_isize -> isize;
479
480 read_bool -> bool;
481 read_f64 -> f64;
482 read_f32 -> f32;
483 read_char -> char;
484 read_str -> Cow<'_, str>;
485 }
486
487 #[inline]
488 fn read_raw_bytes_into(&mut self, bytes: &mut [u8]) -> Result<(), Self::Error> {
489 self.opaque.read_raw_bytes_into(bytes)
490 }
491
492 fn error(&mut self, err: &str) -> Self::Error {
493 self.opaque.error(err)
494 }
495 }
496 }
497 }
498 }
499
500 macro_rules! impl_binder_encode_decode {
501 ($($t:ty),+ $(,)?) => {
502 $(
503 impl<'tcx, E: TyEncoder<'tcx>> Encodable<E> for ty::Binder<'tcx, $t> {
504 fn encode(&self, e: &mut E) -> Result<(), E::Error> {
505 self.bound_vars().encode(e)?;
506 self.as_ref().skip_binder().encode(e)
507 }
508 }
509 impl<'tcx, D: TyDecoder<'tcx>> Decodable<D> for ty::Binder<'tcx, $t> {
510 fn decode(decoder: &mut D) -> Result<Self, D::Error> {
511 let bound_vars = Decodable::decode(decoder)?;
512 Ok(ty::Binder::bind_with_vars(Decodable::decode(decoder)?, bound_vars))
513 }
514 }
515 )*
516 }
517 }
518
519 impl_binder_encode_decode! {
520 &'tcx ty::List<Ty<'tcx>>,
521 ty::FnSig<'tcx>,
522 ty::ExistentialPredicate<'tcx>,
523 ty::TraitRef<'tcx>,
524 Vec<ty::GeneratorInteriorTypeCause<'tcx>>,
525 }
526