1 //! This module contains implements of the `Lift` and `TypeFoldable`
2 //! traits for various types in the Rust compiler. Most are written by
3 //! hand, though we've recently added some macros and proc-macros to help with the tedium.
5 use crate::mir::interpret;
6 use crate::mir::ProjectionKind;
7 use crate::ty::fold::{TypeFoldable, TypeFolder, TypeVisitor};
8 use crate::ty::print::{FmtPrinter, Printer};
9 use crate::ty::{self, InferConst, Lift, Ty, TyCtxt};
11 use rustc_hir::def::Namespace;
12 use rustc_hir::def_id::CRATE_DEF_INDEX;
13 use rustc_index::vec::{Idx, IndexVec};
15 use smallvec::SmallVec;
20 impl fmt::Debug for ty::TraitDef {
21 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
23 FmtPrinter::new(tcx, f, Namespace::TypeNS).print_def_path(self.def_id, &[])?;
29 impl fmt::Debug for ty::AdtDef {
30 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
32 FmtPrinter::new(tcx, f, Namespace::TypeNS).print_def_path(self.did, &[])?;
38 impl fmt::Debug for ty::UpvarId {
39 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
40 let name = ty::tls::with(|tcx| tcx.hir().name(self.var_path.hir_id));
41 write!(f, "UpvarId({:?};`{}`;{:?})", self.var_path.hir_id, name, self.closure_expr_id)
45 impl fmt::Debug for ty::UpvarBorrow<'tcx> {
46 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
47 write!(f, "UpvarBorrow({:?}, {:?})", self.kind, self.region)
51 impl fmt::Debug for ty::ExistentialTraitRef<'tcx> {
52 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
53 fmt::Display::fmt(self, f)
57 impl fmt::Debug for ty::adjustment::Adjustment<'tcx> {
58 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
59 write!(f, "{:?} -> {}", self.kind, self.target)
63 impl fmt::Debug for ty::BoundRegion {
64 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
66 ty::BrAnon(n) => write!(f, "BrAnon({:?})", n),
67 ty::BrNamed(did, name) => {
68 if did.index == CRATE_DEF_INDEX {
69 write!(f, "BrNamed({})", name)
71 write!(f, "BrNamed({:?}, {})", did, name)
74 ty::BrEnv => write!(f, "BrEnv"),
79 impl fmt::Debug for ty::RegionKind {
80 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
82 ty::ReEarlyBound(ref data) => write!(f, "ReEarlyBound({}, {})", data.index, data.name),
84 ty::ReLateBound(binder_id, ref bound_region) => {
85 write!(f, "ReLateBound({:?}, {:?})", binder_id, bound_region)
88 ty::ReFree(ref fr) => fr.fmt(f),
90 ty::ReStatic => write!(f, "ReStatic"),
92 ty::ReVar(ref vid) => vid.fmt(f),
94 ty::RePlaceholder(placeholder) => write!(f, "RePlaceholder({:?})", placeholder),
96 ty::ReEmpty(ui) => write!(f, "ReEmpty({:?})", ui),
98 ty::ReErased => write!(f, "ReErased"),
103 impl fmt::Debug for ty::FreeRegion {
104 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
105 write!(f, "ReFree({:?}, {:?})", self.scope, self.bound_region)
109 impl fmt::Debug for ty::Variance {
110 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
111 f.write_str(match *self {
112 ty::Covariant => "+",
113 ty::Contravariant => "-",
114 ty::Invariant => "o",
115 ty::Bivariant => "*",
120 impl fmt::Debug for ty::FnSig<'tcx> {
121 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
122 write!(f, "({:?}; c_variadic: {})->{:?}", self.inputs(), self.c_variadic, self.output())
126 impl fmt::Debug for ty::TyVid {
127 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
128 write!(f, "_#{}t", self.index)
132 impl<'tcx> fmt::Debug for ty::ConstVid<'tcx> {
133 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
134 write!(f, "_#{}c", self.index)
138 impl fmt::Debug for ty::IntVid {
139 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
140 write!(f, "_#{}i", self.index)
144 impl fmt::Debug for ty::FloatVid {
145 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
146 write!(f, "_#{}f", self.index)
150 impl fmt::Debug for ty::RegionVid {
151 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
152 write!(f, "'_#{}r", self.index())
156 impl fmt::Debug for ty::InferTy {
157 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
159 ty::TyVar(ref v) => v.fmt(f),
160 ty::IntVar(ref v) => v.fmt(f),
161 ty::FloatVar(ref v) => v.fmt(f),
162 ty::FreshTy(v) => write!(f, "FreshTy({:?})", v),
163 ty::FreshIntTy(v) => write!(f, "FreshIntTy({:?})", v),
164 ty::FreshFloatTy(v) => write!(f, "FreshFloatTy({:?})", v),
169 impl fmt::Debug for ty::IntVarValue {
170 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
172 ty::IntType(ref v) => v.fmt(f),
173 ty::UintType(ref v) => v.fmt(f),
178 impl fmt::Debug for ty::FloatVarValue {
179 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
184 impl fmt::Debug for ty::TraitRef<'tcx> {
185 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
186 fmt::Display::fmt(self, f)
190 impl fmt::Debug for Ty<'tcx> {
191 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
192 fmt::Display::fmt(self, f)
196 impl fmt::Debug for ty::ParamTy {
197 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
198 write!(f, "{}/#{}", self.name, self.index)
202 impl fmt::Debug for ty::ParamConst {
203 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
204 write!(f, "{}/#{}", self.name, self.index)
208 impl fmt::Debug for ty::TraitPredicate<'tcx> {
209 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
210 write!(f, "TraitPredicate({:?})", self.trait_ref)
214 impl fmt::Debug for ty::ProjectionPredicate<'tcx> {
215 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
216 write!(f, "ProjectionPredicate({:?}, {:?})", self.projection_ty, self.ty)
220 impl fmt::Debug for ty::Predicate<'tcx> {
221 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
222 write!(f, "{:?}", self.kind())
226 impl fmt::Debug for ty::PredicateKind<'tcx> {
227 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
229 ty::PredicateKind::Trait(ref a, constness) => {
230 if let hir::Constness::Const = constness {
231 write!(f, "const ")?;
235 ty::PredicateKind::Subtype(ref pair) => pair.fmt(f),
236 ty::PredicateKind::RegionOutlives(ref pair) => pair.fmt(f),
237 ty::PredicateKind::TypeOutlives(ref pair) => pair.fmt(f),
238 ty::PredicateKind::Projection(ref pair) => pair.fmt(f),
239 ty::PredicateKind::WellFormed(data) => write!(f, "WellFormed({:?})", data),
240 ty::PredicateKind::ObjectSafe(trait_def_id) => {
241 write!(f, "ObjectSafe({:?})", trait_def_id)
243 ty::PredicateKind::ClosureKind(closure_def_id, closure_substs, kind) => {
244 write!(f, "ClosureKind({:?}, {:?}, {:?})", closure_def_id, closure_substs, kind)
246 ty::PredicateKind::ConstEvaluatable(def_id, substs) => {
247 write!(f, "ConstEvaluatable({:?}, {:?})", def_id, substs)
249 ty::PredicateKind::ConstEquate(c1, c2) => write!(f, "ConstEquate({:?}, {:?})", c1, c2),
254 ///////////////////////////////////////////////////////////////////////////
257 // For things that don't carry any arena-allocated data (and are
258 // copy...), just add them to this list.
260 CloneTypeFoldableAndLiftImpls! {
264 ::rustc_target::abi::VariantIdx,
267 crate::middle::region::Scope,
268 ::rustc_ast::ast::FloatTy,
269 ::rustc_ast::ast::InlineAsmOptions,
270 ::rustc_ast::ast::InlineAsmTemplatePiece,
271 ::rustc_ast::ast::NodeId,
272 ::rustc_span::symbol::Symbol,
273 ::rustc_hir::def::Res,
274 ::rustc_hir::def_id::DefId,
275 ::rustc_hir::LlvmInlineAsmInner,
276 ::rustc_hir::MatchSource,
277 ::rustc_hir::Mutability,
278 ::rustc_hir::Unsafety,
279 ::rustc_target::asm::InlineAsmRegOrRegClass,
280 ::rustc_target::spec::abi::Abi,
282 crate::mir::Promoted,
283 crate::traits::Reveal,
284 crate::ty::adjustment::AutoBorrowMutability,
286 // Including `BoundRegion` is a *bit* dubious, but direct
287 // references to bound region appear in `ty::Error`, and aren't
288 // really meant to be folded. In general, we can only fold a fully
290 crate::ty::BoundRegion,
291 crate::ty::Placeholder<crate::ty::BoundRegion>,
292 crate::ty::ClosureKind,
293 crate::ty::FreeRegion,
295 crate::ty::IntVarValue,
296 crate::ty::ParamConst,
298 crate::ty::adjustment::PointerCast,
299 crate::ty::RegionVid,
300 crate::ty::UniverseIndex,
305 ///////////////////////////////////////////////////////////////////////////
306 // Lift implementations
308 // FIXME(eddyb) replace all the uses of `Option::map` with `?`.
309 impl<'tcx, A: Lift<'tcx>, B: Lift<'tcx>> Lift<'tcx> for (A, B) {
310 type Lifted = (A::Lifted, B::Lifted);
311 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
312 tcx.lift(&self.0).and_then(|a| tcx.lift(&self.1).map(|b| (a, b)))
316 impl<'tcx, A: Lift<'tcx>, B: Lift<'tcx>, C: Lift<'tcx>> Lift<'tcx> for (A, B, C) {
317 type Lifted = (A::Lifted, B::Lifted, C::Lifted);
318 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
320 .and_then(|a| tcx.lift(&self.1).and_then(|b| tcx.lift(&self.2).map(|c| (a, b, c))))
324 impl<'tcx, T: Lift<'tcx>> Lift<'tcx> for Option<T> {
325 type Lifted = Option<T::Lifted>;
326 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
328 Some(ref x) => tcx.lift(x).map(Some),
334 impl<'tcx, T: Lift<'tcx>, E: Lift<'tcx>> Lift<'tcx> for Result<T, E> {
335 type Lifted = Result<T::Lifted, E::Lifted>;
336 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
338 Ok(ref x) => tcx.lift(x).map(Ok),
339 Err(ref e) => tcx.lift(e).map(Err),
344 impl<'tcx, T: Lift<'tcx>> Lift<'tcx> for Box<T> {
345 type Lifted = Box<T::Lifted>;
346 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
347 tcx.lift(&**self).map(Box::new)
351 impl<'tcx, T: Lift<'tcx>> Lift<'tcx> for Rc<T> {
352 type Lifted = Rc<T::Lifted>;
353 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
354 tcx.lift(&**self).map(Rc::new)
358 impl<'tcx, T: Lift<'tcx>> Lift<'tcx> for Arc<T> {
359 type Lifted = Arc<T::Lifted>;
360 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
361 tcx.lift(&**self).map(Arc::new)
365 impl<'tcx, T: Lift<'tcx>> Lift<'tcx> for [T] {
366 type Lifted = Vec<T::Lifted>;
367 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
368 // type annotation needed to inform `projection_must_outlive`
369 let mut result: Vec<<T as Lift<'tcx>>::Lifted> = Vec::with_capacity(self.len());
371 if let Some(value) = tcx.lift(x) {
381 impl<'tcx, T: Lift<'tcx>> Lift<'tcx> for Vec<T> {
382 type Lifted = Vec<T::Lifted>;
383 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
388 impl<'tcx, I: Idx, T: Lift<'tcx>> Lift<'tcx> for IndexVec<I, T> {
389 type Lifted = IndexVec<I, T::Lifted>;
390 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
391 self.iter().map(|e| tcx.lift(e)).collect()
395 impl<'a, 'tcx> Lift<'tcx> for ty::TraitRef<'a> {
396 type Lifted = ty::TraitRef<'tcx>;
397 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
398 tcx.lift(&self.substs).map(|substs| ty::TraitRef { def_id: self.def_id, substs })
402 impl<'a, 'tcx> Lift<'tcx> for ty::ExistentialTraitRef<'a> {
403 type Lifted = ty::ExistentialTraitRef<'tcx>;
404 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
405 tcx.lift(&self.substs).map(|substs| ty::ExistentialTraitRef { def_id: self.def_id, substs })
409 impl<'a, 'tcx> Lift<'tcx> for ty::ExistentialPredicate<'a> {
410 type Lifted = ty::ExistentialPredicate<'tcx>;
411 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
413 ty::ExistentialPredicate::Trait(x) => tcx.lift(x).map(ty::ExistentialPredicate::Trait),
414 ty::ExistentialPredicate::Projection(x) => {
415 tcx.lift(x).map(ty::ExistentialPredicate::Projection)
417 ty::ExistentialPredicate::AutoTrait(def_id) => {
418 Some(ty::ExistentialPredicate::AutoTrait(*def_id))
424 impl<'a, 'tcx> Lift<'tcx> for ty::TraitPredicate<'a> {
425 type Lifted = ty::TraitPredicate<'tcx>;
426 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<ty::TraitPredicate<'tcx>> {
427 tcx.lift(&self.trait_ref).map(|trait_ref| ty::TraitPredicate { trait_ref })
431 impl<'a, 'tcx> Lift<'tcx> for ty::SubtypePredicate<'a> {
432 type Lifted = ty::SubtypePredicate<'tcx>;
433 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<ty::SubtypePredicate<'tcx>> {
434 tcx.lift(&(self.a, self.b)).map(|(a, b)| ty::SubtypePredicate {
435 a_is_expected: self.a_is_expected,
442 impl<'tcx, A: Copy + Lift<'tcx>, B: Copy + Lift<'tcx>> Lift<'tcx> for ty::OutlivesPredicate<A, B> {
443 type Lifted = ty::OutlivesPredicate<A::Lifted, B::Lifted>;
444 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
445 tcx.lift(&(self.0, self.1)).map(|(a, b)| ty::OutlivesPredicate(a, b))
449 impl<'a, 'tcx> Lift<'tcx> for ty::ProjectionTy<'a> {
450 type Lifted = ty::ProjectionTy<'tcx>;
451 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<ty::ProjectionTy<'tcx>> {
452 tcx.lift(&self.substs)
453 .map(|substs| ty::ProjectionTy { item_def_id: self.item_def_id, substs })
457 impl<'a, 'tcx> Lift<'tcx> for ty::ProjectionPredicate<'a> {
458 type Lifted = ty::ProjectionPredicate<'tcx>;
459 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<ty::ProjectionPredicate<'tcx>> {
460 tcx.lift(&(self.projection_ty, self.ty))
461 .map(|(projection_ty, ty)| ty::ProjectionPredicate { projection_ty, ty })
465 impl<'a, 'tcx> Lift<'tcx> for ty::ExistentialProjection<'a> {
466 type Lifted = ty::ExistentialProjection<'tcx>;
467 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
468 tcx.lift(&self.substs).map(|substs| ty::ExistentialProjection {
470 ty: tcx.lift(&self.ty).expect("type must lift when substs do"),
471 item_def_id: self.item_def_id,
476 impl<'a, 'tcx> Lift<'tcx> for ty::PredicateKind<'a> {
477 type Lifted = ty::PredicateKind<'tcx>;
478 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
480 ty::PredicateKind::Trait(ref binder, constness) => {
481 tcx.lift(binder).map(|binder| ty::PredicateKind::Trait(binder, constness))
483 ty::PredicateKind::Subtype(ref binder) => {
484 tcx.lift(binder).map(ty::PredicateKind::Subtype)
486 ty::PredicateKind::RegionOutlives(ref binder) => {
487 tcx.lift(binder).map(ty::PredicateKind::RegionOutlives)
489 ty::PredicateKind::TypeOutlives(ref binder) => {
490 tcx.lift(binder).map(ty::PredicateKind::TypeOutlives)
492 ty::PredicateKind::Projection(ref binder) => {
493 tcx.lift(binder).map(ty::PredicateKind::Projection)
495 ty::PredicateKind::WellFormed(ty) => tcx.lift(&ty).map(ty::PredicateKind::WellFormed),
496 ty::PredicateKind::ClosureKind(closure_def_id, closure_substs, kind) => {
497 tcx.lift(&closure_substs).map(|closure_substs| {
498 ty::PredicateKind::ClosureKind(closure_def_id, closure_substs, kind)
501 ty::PredicateKind::ObjectSafe(trait_def_id) => {
502 Some(ty::PredicateKind::ObjectSafe(trait_def_id))
504 ty::PredicateKind::ConstEvaluatable(def_id, substs) => {
505 tcx.lift(&substs).map(|substs| ty::PredicateKind::ConstEvaluatable(def_id, substs))
507 ty::PredicateKind::ConstEquate(c1, c2) => {
508 tcx.lift(&(c1, c2)).map(|(c1, c2)| ty::PredicateKind::ConstEquate(c1, c2))
514 impl<'tcx, T: Lift<'tcx>> Lift<'tcx> for ty::Binder<T> {
515 type Lifted = ty::Binder<T::Lifted>;
516 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
517 tcx.lift(self.as_ref().skip_binder()).map(ty::Binder::bind)
521 impl<'a, 'tcx> Lift<'tcx> for ty::ParamEnv<'a> {
522 type Lifted = ty::ParamEnv<'tcx>;
523 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
524 tcx.lift(&self.caller_bounds())
525 .map(|caller_bounds| ty::ParamEnv::new(caller_bounds, self.reveal(), self.def_id))
529 impl<'a, 'tcx, T: Lift<'tcx>> Lift<'tcx> for ty::ParamEnvAnd<'a, T> {
530 type Lifted = ty::ParamEnvAnd<'tcx, T::Lifted>;
531 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
532 tcx.lift(&self.param_env).and_then(|param_env| {
533 tcx.lift(&self.value).map(|value| ty::ParamEnvAnd { param_env, value })
538 impl<'a, 'tcx> Lift<'tcx> for ty::ClosureSubsts<'a> {
539 type Lifted = ty::ClosureSubsts<'tcx>;
540 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
541 tcx.lift(&self.substs).map(|substs| ty::ClosureSubsts { substs })
545 impl<'a, 'tcx> Lift<'tcx> for ty::GeneratorSubsts<'a> {
546 type Lifted = ty::GeneratorSubsts<'tcx>;
547 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
548 tcx.lift(&self.substs).map(|substs| ty::GeneratorSubsts { substs })
552 impl<'a, 'tcx> Lift<'tcx> for ty::adjustment::Adjustment<'a> {
553 type Lifted = ty::adjustment::Adjustment<'tcx>;
554 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
555 tcx.lift(&self.kind).and_then(|kind| {
556 tcx.lift(&self.target).map(|target| ty::adjustment::Adjustment { kind, target })
561 impl<'a, 'tcx> Lift<'tcx> for ty::adjustment::Adjust<'a> {
562 type Lifted = ty::adjustment::Adjust<'tcx>;
563 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
565 ty::adjustment::Adjust::NeverToAny => Some(ty::adjustment::Adjust::NeverToAny),
566 ty::adjustment::Adjust::Pointer(ptr) => Some(ty::adjustment::Adjust::Pointer(ptr)),
567 ty::adjustment::Adjust::Deref(ref overloaded) => {
568 tcx.lift(overloaded).map(ty::adjustment::Adjust::Deref)
570 ty::adjustment::Adjust::Borrow(ref autoref) => {
571 tcx.lift(autoref).map(ty::adjustment::Adjust::Borrow)
577 impl<'a, 'tcx> Lift<'tcx> for ty::adjustment::OverloadedDeref<'a> {
578 type Lifted = ty::adjustment::OverloadedDeref<'tcx>;
579 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
580 tcx.lift(&self.region)
581 .map(|region| ty::adjustment::OverloadedDeref { region, mutbl: self.mutbl })
585 impl<'a, 'tcx> Lift<'tcx> for ty::adjustment::AutoBorrow<'a> {
586 type Lifted = ty::adjustment::AutoBorrow<'tcx>;
587 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
589 ty::adjustment::AutoBorrow::Ref(r, m) => {
590 tcx.lift(&r).map(|r| ty::adjustment::AutoBorrow::Ref(r, m))
592 ty::adjustment::AutoBorrow::RawPtr(m) => Some(ty::adjustment::AutoBorrow::RawPtr(m)),
597 impl<'a, 'tcx> Lift<'tcx> for ty::GenSig<'a> {
598 type Lifted = ty::GenSig<'tcx>;
599 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
600 tcx.lift(&(self.resume_ty, self.yield_ty, self.return_ty))
601 .map(|(resume_ty, yield_ty, return_ty)| ty::GenSig { resume_ty, yield_ty, return_ty })
605 impl<'a, 'tcx> Lift<'tcx> for ty::FnSig<'a> {
606 type Lifted = ty::FnSig<'tcx>;
607 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
608 tcx.lift(&self.inputs_and_output).map(|x| ty::FnSig {
609 inputs_and_output: x,
610 c_variadic: self.c_variadic,
611 unsafety: self.unsafety,
617 impl<'tcx, T: Lift<'tcx>> Lift<'tcx> for ty::error::ExpectedFound<T> {
618 type Lifted = ty::error::ExpectedFound<T::Lifted>;
619 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
620 tcx.lift(&self.expected).and_then(|expected| {
621 tcx.lift(&self.found).map(|found| ty::error::ExpectedFound { expected, found })
626 impl<'a, 'tcx> Lift<'tcx> for ty::error::TypeError<'a> {
627 type Lifted = ty::error::TypeError<'tcx>;
628 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
629 use crate::ty::error::TypeError::*;
632 Mismatch => Mismatch,
633 UnsafetyMismatch(x) => UnsafetyMismatch(x),
634 AbiMismatch(x) => AbiMismatch(x),
635 Mutability => Mutability,
636 TupleSize(x) => TupleSize(x),
637 FixedArraySize(x) => FixedArraySize(x),
638 ArgCount => ArgCount,
639 RegionsDoesNotOutlive(a, b) => {
640 return tcx.lift(&(a, b)).map(|(a, b)| RegionsDoesNotOutlive(a, b));
642 RegionsInsufficientlyPolymorphic(a, b) => {
643 return tcx.lift(&b).map(|b| RegionsInsufficientlyPolymorphic(a, b));
645 RegionsOverlyPolymorphic(a, b) => {
646 return tcx.lift(&b).map(|b| RegionsOverlyPolymorphic(a, b));
648 RegionsPlaceholderMismatch => RegionsPlaceholderMismatch,
649 IntMismatch(x) => IntMismatch(x),
650 FloatMismatch(x) => FloatMismatch(x),
651 Traits(x) => Traits(x),
652 VariadicMismatch(x) => VariadicMismatch(x),
653 CyclicTy(t) => return tcx.lift(&t).map(|t| CyclicTy(t)),
654 ProjectionMismatched(x) => ProjectionMismatched(x),
655 Sorts(ref x) => return tcx.lift(x).map(Sorts),
656 ExistentialMismatch(ref x) => return tcx.lift(x).map(ExistentialMismatch),
657 ConstMismatch(ref x) => return tcx.lift(x).map(ConstMismatch),
658 IntrinsicCast => IntrinsicCast,
659 TargetFeatureCast(ref x) => TargetFeatureCast(*x),
660 ObjectUnsafeCoercion(ref x) => return tcx.lift(x).map(ObjectUnsafeCoercion),
665 impl<'a, 'tcx> Lift<'tcx> for ty::InstanceDef<'a> {
666 type Lifted = ty::InstanceDef<'tcx>;
667 fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
669 ty::InstanceDef::Item(def_id) => Some(ty::InstanceDef::Item(def_id)),
670 ty::InstanceDef::VtableShim(def_id) => Some(ty::InstanceDef::VtableShim(def_id)),
671 ty::InstanceDef::ReifyShim(def_id) => Some(ty::InstanceDef::ReifyShim(def_id)),
672 ty::InstanceDef::Intrinsic(def_id) => Some(ty::InstanceDef::Intrinsic(def_id)),
673 ty::InstanceDef::FnPtrShim(def_id, ref ty) => {
674 Some(ty::InstanceDef::FnPtrShim(def_id, tcx.lift(ty)?))
676 ty::InstanceDef::Virtual(def_id, n) => Some(ty::InstanceDef::Virtual(def_id, n)),
677 ty::InstanceDef::ClosureOnceShim { call_once } => {
678 Some(ty::InstanceDef::ClosureOnceShim { call_once })
680 ty::InstanceDef::DropGlue(def_id, ref ty) => {
681 Some(ty::InstanceDef::DropGlue(def_id, tcx.lift(ty)?))
683 ty::InstanceDef::CloneShim(def_id, ref ty) => {
684 Some(ty::InstanceDef::CloneShim(def_id, tcx.lift(ty)?))
690 ///////////////////////////////////////////////////////////////////////////
691 // TypeFoldable implementations.
693 // Ideally, each type should invoke `folder.fold_foo(self)` and
694 // nothing else. In some cases, though, we haven't gotten around to
695 // adding methods on the `folder` yet, and thus the folding is
696 // hard-coded here. This is less-flexible, because folders cannot
697 // override the behavior, but there are a lot of random types and one
698 // can easily refactor the folding into the TypeFolder trait as
701 /// AdtDefs are basically the same as a DefId.
702 impl<'tcx> TypeFoldable<'tcx> for &'tcx ty::AdtDef {
703 fn super_fold_with<F: TypeFolder<'tcx>>(&self, _folder: &mut F) -> Self {
707 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, _visitor: &mut V) -> bool {
712 impl<'tcx, T: TypeFoldable<'tcx>, U: TypeFoldable<'tcx>> TypeFoldable<'tcx> for (T, U) {
713 fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> (T, U) {
714 (self.0.fold_with(folder), self.1.fold_with(folder))
717 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
718 self.0.visit_with(visitor) || self.1.visit_with(visitor)
722 EnumTypeFoldableImpl! {
723 impl<'tcx, T> TypeFoldable<'tcx> for Option<T> {
726 } where T: TypeFoldable<'tcx>
729 EnumTypeFoldableImpl! {
730 impl<'tcx, T, E> TypeFoldable<'tcx> for Result<T, E> {
733 } where T: TypeFoldable<'tcx>, E: TypeFoldable<'tcx>,
736 impl<'tcx, T: TypeFoldable<'tcx>> TypeFoldable<'tcx> for Rc<T> {
737 fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
738 Rc::new((**self).fold_with(folder))
741 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
742 (**self).visit_with(visitor)
746 impl<'tcx, T: TypeFoldable<'tcx>> TypeFoldable<'tcx> for Arc<T> {
747 fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
748 Arc::new((**self).fold_with(folder))
751 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
752 (**self).visit_with(visitor)
756 impl<'tcx, T: TypeFoldable<'tcx>> TypeFoldable<'tcx> for Box<T> {
757 fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
758 let content: T = (**self).fold_with(folder);
762 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
763 (**self).visit_with(visitor)
767 impl<'tcx, T: TypeFoldable<'tcx>> TypeFoldable<'tcx> for Vec<T> {
768 fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
769 self.iter().map(|t| t.fold_with(folder)).collect()
772 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
773 self.iter().any(|t| t.visit_with(visitor))
777 impl<'tcx, T: TypeFoldable<'tcx>> TypeFoldable<'tcx> for Box<[T]> {
778 fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
779 self.iter().map(|t| t.fold_with(folder)).collect::<Vec<_>>().into_boxed_slice()
782 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
783 self.iter().any(|t| t.visit_with(visitor))
787 impl<'tcx, T: TypeFoldable<'tcx>> TypeFoldable<'tcx> for ty::Binder<T> {
788 fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
789 self.map_bound_ref(|ty| ty.fold_with(folder))
792 fn fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
793 folder.fold_binder(self)
796 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
797 self.as_ref().skip_binder().visit_with(visitor)
800 fn visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
801 visitor.visit_binder(self)
805 impl<'tcx> TypeFoldable<'tcx> for &'tcx ty::List<ty::ExistentialPredicate<'tcx>> {
806 fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
807 fold_list(*self, folder, |tcx, v| tcx.intern_existential_predicates(v))
810 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
811 self.iter().any(|p| p.visit_with(visitor))
815 impl<'tcx> TypeFoldable<'tcx> for &'tcx ty::List<Ty<'tcx>> {
816 fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
817 fold_list(*self, folder, |tcx, v| tcx.intern_type_list(v))
820 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
821 self.iter().any(|t| t.visit_with(visitor))
825 impl<'tcx> TypeFoldable<'tcx> for &'tcx ty::List<ProjectionKind> {
826 fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
827 fold_list(*self, folder, |tcx, v| tcx.intern_projs(v))
830 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
831 self.iter().any(|t| t.visit_with(visitor))
835 impl<'tcx> TypeFoldable<'tcx> for ty::instance::Instance<'tcx> {
836 fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
837 use crate::ty::InstanceDef::*;
839 substs: self.substs.fold_with(folder),
840 def: match self.def {
841 Item(did) => Item(did.fold_with(folder)),
842 VtableShim(did) => VtableShim(did.fold_with(folder)),
843 ReifyShim(did) => ReifyShim(did.fold_with(folder)),
844 Intrinsic(did) => Intrinsic(did.fold_with(folder)),
845 FnPtrShim(did, ty) => FnPtrShim(did.fold_with(folder), ty.fold_with(folder)),
846 Virtual(did, i) => Virtual(did.fold_with(folder), i),
847 ClosureOnceShim { call_once } => {
848 ClosureOnceShim { call_once: call_once.fold_with(folder) }
850 DropGlue(did, ty) => DropGlue(did.fold_with(folder), ty.fold_with(folder)),
851 CloneShim(did, ty) => CloneShim(did.fold_with(folder), ty.fold_with(folder)),
856 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
857 use crate::ty::InstanceDef::*;
858 self.substs.visit_with(visitor)
860 Item(did) | VtableShim(did) | ReifyShim(did) | Intrinsic(did) | Virtual(did, _) => {
861 did.visit_with(visitor)
863 FnPtrShim(did, ty) | CloneShim(did, ty) => {
864 did.visit_with(visitor) || ty.visit_with(visitor)
866 DropGlue(did, ty) => did.visit_with(visitor) || ty.visit_with(visitor),
867 ClosureOnceShim { call_once } => call_once.visit_with(visitor),
872 impl<'tcx> TypeFoldable<'tcx> for interpret::GlobalId<'tcx> {
873 fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
874 Self { instance: self.instance.fold_with(folder), promoted: self.promoted }
877 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
878 self.instance.visit_with(visitor)
882 impl<'tcx> TypeFoldable<'tcx> for Ty<'tcx> {
883 fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
884 let kind = match self.kind {
885 ty::RawPtr(tm) => ty::RawPtr(tm.fold_with(folder)),
886 ty::Array(typ, sz) => ty::Array(typ.fold_with(folder), sz.fold_with(folder)),
887 ty::Slice(typ) => ty::Slice(typ.fold_with(folder)),
888 ty::Adt(tid, substs) => ty::Adt(tid, substs.fold_with(folder)),
889 ty::Dynamic(ref trait_ty, ref region) => {
890 ty::Dynamic(trait_ty.fold_with(folder), region.fold_with(folder))
892 ty::Tuple(ts) => ty::Tuple(ts.fold_with(folder)),
893 ty::FnDef(def_id, substs) => ty::FnDef(def_id, substs.fold_with(folder)),
894 ty::FnPtr(f) => ty::FnPtr(f.fold_with(folder)),
895 ty::Ref(ref r, ty, mutbl) => ty::Ref(r.fold_with(folder), ty.fold_with(folder), mutbl),
896 ty::Generator(did, substs, movability) => {
897 ty::Generator(did, substs.fold_with(folder), movability)
899 ty::GeneratorWitness(types) => ty::GeneratorWitness(types.fold_with(folder)),
900 ty::Closure(did, substs) => ty::Closure(did, substs.fold_with(folder)),
901 ty::Projection(ref data) => ty::Projection(data.fold_with(folder)),
902 ty::Opaque(did, substs) => ty::Opaque(did, substs.fold_with(folder)),
914 | ty::Placeholder(..)
916 | ty::Foreign(..) => return self,
919 if self.kind == kind { self } else { folder.tcx().mk_ty(kind) }
922 fn fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
923 folder.fold_ty(*self)
926 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
928 ty::RawPtr(ref tm) => tm.visit_with(visitor),
929 ty::Array(typ, sz) => typ.visit_with(visitor) || sz.visit_with(visitor),
930 ty::Slice(typ) => typ.visit_with(visitor),
931 ty::Adt(_, substs) => substs.visit_with(visitor),
932 ty::Dynamic(ref trait_ty, ref reg) => {
933 trait_ty.visit_with(visitor) || reg.visit_with(visitor)
935 ty::Tuple(ts) => ts.visit_with(visitor),
936 ty::FnDef(_, substs) => substs.visit_with(visitor),
937 ty::FnPtr(ref f) => f.visit_with(visitor),
938 ty::Ref(r, ty, _) => r.visit_with(visitor) || ty.visit_with(visitor),
939 ty::Generator(_did, ref substs, _) => substs.visit_with(visitor),
940 ty::GeneratorWitness(ref types) => types.visit_with(visitor),
941 ty::Closure(_did, ref substs) => substs.visit_with(visitor),
942 ty::Projection(ref data) => data.visit_with(visitor),
943 ty::Opaque(_, ref substs) => substs.visit_with(visitor),
954 | ty::Placeholder(..)
957 | ty::Foreign(..) => false,
961 fn visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
962 visitor.visit_ty(self)
966 impl<'tcx> TypeFoldable<'tcx> for ty::Region<'tcx> {
967 fn super_fold_with<F: TypeFolder<'tcx>>(&self, _folder: &mut F) -> Self {
971 fn fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
972 folder.fold_region(*self)
975 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, _visitor: &mut V) -> bool {
979 fn visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
980 visitor.visit_region(*self)
984 impl<'tcx> TypeFoldable<'tcx> for ty::Predicate<'tcx> {
985 fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
986 let new = ty::PredicateKind::super_fold_with(&self.inner.kind, folder);
987 if new != self.inner.kind { folder.tcx().mk_predicate(new) } else { *self }
990 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
991 ty::PredicateKind::super_visit_with(&self.inner.kind, visitor)
994 fn visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
995 visitor.visit_predicate(*self)
998 fn has_vars_bound_at_or_above(&self, binder: ty::DebruijnIndex) -> bool {
999 self.inner.outer_exclusive_binder > binder
1002 fn has_type_flags(&self, flags: ty::TypeFlags) -> bool {
1003 self.inner.flags.intersects(flags)
1007 pub(super) trait PredicateVisitor<'tcx>: TypeVisitor<'tcx> {
1008 fn visit_predicate(&mut self, predicate: ty::Predicate<'tcx>) -> bool;
1011 impl<T: TypeVisitor<'tcx>> PredicateVisitor<'tcx> for T {
1012 default fn visit_predicate(&mut self, predicate: ty::Predicate<'tcx>) -> bool {
1013 predicate.super_visit_with(self)
1017 impl<'tcx> TypeFoldable<'tcx> for &'tcx ty::List<ty::Predicate<'tcx>> {
1018 fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
1019 fold_list(*self, folder, |tcx, v| tcx.intern_predicates(v))
1022 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
1023 self.iter().any(|p| p.visit_with(visitor))
1027 impl<'tcx, T: TypeFoldable<'tcx>, I: Idx> TypeFoldable<'tcx> for IndexVec<I, T> {
1028 fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
1029 self.iter().map(|x| x.fold_with(folder)).collect()
1032 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
1033 self.iter().any(|t| t.visit_with(visitor))
1037 impl<'tcx> TypeFoldable<'tcx> for &'tcx ty::Const<'tcx> {
1038 fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
1039 let ty = self.ty.fold_with(folder);
1040 let val = self.val.fold_with(folder);
1041 if ty != self.ty || val != self.val {
1042 folder.tcx().mk_const(ty::Const { ty, val })
1048 fn fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
1049 folder.fold_const(*self)
1052 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
1053 self.ty.visit_with(visitor) || self.val.visit_with(visitor)
1056 fn visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
1057 visitor.visit_const(self)
1061 impl<'tcx> TypeFoldable<'tcx> for ty::ConstKind<'tcx> {
1062 fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
1064 ty::ConstKind::Infer(ic) => ty::ConstKind::Infer(ic.fold_with(folder)),
1065 ty::ConstKind::Param(p) => ty::ConstKind::Param(p.fold_with(folder)),
1066 ty::ConstKind::Unevaluated(did, substs, promoted) => {
1067 ty::ConstKind::Unevaluated(did, substs.fold_with(folder), promoted)
1069 ty::ConstKind::Value(_)
1070 | ty::ConstKind::Bound(..)
1071 | ty::ConstKind::Placeholder(..)
1072 | ty::ConstKind::Error(_) => *self,
1076 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
1078 ty::ConstKind::Infer(ic) => ic.visit_with(visitor),
1079 ty::ConstKind::Param(p) => p.visit_with(visitor),
1080 ty::ConstKind::Unevaluated(_, substs, _) => substs.visit_with(visitor),
1081 ty::ConstKind::Value(_)
1082 | ty::ConstKind::Bound(..)
1083 | ty::ConstKind::Placeholder(_)
1084 | ty::ConstKind::Error(_) => false,
1089 impl<'tcx> TypeFoldable<'tcx> for InferConst<'tcx> {
1090 fn super_fold_with<F: TypeFolder<'tcx>>(&self, _folder: &mut F) -> Self {
1094 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, _visitor: &mut V) -> bool {
1099 // Does the equivalent of
1101 // let v = self.iter().map(|p| p.fold_with(folder)).collect::<SmallVec<[_; 8]>>();
1102 // folder.tcx().intern_*(&v)
1104 fn fold_list<'tcx, F, T>(
1105 list: &'tcx ty::List<T>,
1107 intern: impl FnOnce(TyCtxt<'tcx>, &[T]) -> &'tcx ty::List<T>,
1108 ) -> &'tcx ty::List<T>
1110 F: TypeFolder<'tcx>,
1111 T: TypeFoldable<'tcx> + PartialEq + Copy,
1113 let mut iter = list.iter();
1114 // Look for the first element that changed
1115 if let Some((i, new_t)) = iter.by_ref().enumerate().find_map(|(i, t)| {
1116 let new_t = t.fold_with(folder);
1117 if new_t == t { None } else { Some((i, new_t)) }
1119 // An element changed, prepare to intern the resulting list
1120 let mut new_list = SmallVec::<[_; 8]>::with_capacity(list.len());
1121 new_list.extend_from_slice(&list[..i]);
1122 new_list.push(new_t);
1123 new_list.extend(iter.map(|t| t.fold_with(folder)));
1124 intern(folder.tcx(), &new_list)