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fc512014 XL |
1 | //! Defines how the compiler represents types internally. |
2 | //! | |
3 | //! Two important entities in this module are: | |
4 | //! | |
5 | //! - [`rustc_middle::ty::Ty`], used to represent the semantics of a type. | |
6 | //! - [`rustc_middle::ty::TyCtxt`], the central data structure in the compiler. | |
7 | //! | |
8 | //! For more information, see ["The `ty` module: representing types"] in the ructc-dev-guide. | |
9 | //! | |
10 | //! ["The `ty` module: representing types"]: https://rustc-dev-guide.rust-lang.org/ty.html | |
11 | ||
3dfed10e | 12 | pub use self::fold::{TypeFoldable, TypeFolder, TypeVisitor}; |
dc9dc135 | 13 | pub use self::AssocItemContainer::*; |
e9174d1e | 14 | pub use self::BorrowKind::*; |
e9174d1e | 15 | pub use self::IntVarValue::*; |
dfeec247 | 16 | pub use self::Variance::*; |
6a06907d XL |
17 | pub use adt::*; |
18 | pub use assoc::*; | |
6a06907d | 19 | pub use generics::*; |
136023e0 | 20 | pub use vtable::*; |
dfeec247 | 21 | |
dfeec247 | 22 | use crate::hir::exports::ExportMap; |
6a06907d | 23 | use crate::mir::{Body, GeneratorLayout}; |
9fa01778 XL |
24 | use crate::traits::{self, Reveal}; |
25 | use crate::ty; | |
f035d41b | 26 | use crate::ty::subst::{GenericArg, InternalSubsts, Subst, SubstsRef}; |
6a06907d | 27 | use crate::ty::util::Discr; |
3dfed10e | 28 | use rustc_ast as ast; |
74b04a01 | 29 | use rustc_attr as attr; |
6a06907d | 30 | use rustc_data_structures::fx::{FxHashMap, FxHashSet}; |
dfeec247 | 31 | use rustc_data_structures::stable_hasher::{HashStable, StableHasher}; |
3dfed10e | 32 | use rustc_data_structures::tagged_ptr::CopyTaggedPtr; |
dfeec247 | 33 | use rustc_hir as hir; |
6a06907d | 34 | use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res}; |
17df50a5 | 35 | use rustc_hir::def_id::{CrateNum, DefId, LocalDefId, LocalDefIdMap, CRATE_DEF_INDEX}; |
94222f64 | 36 | use rustc_hir::Node; |
dfeec247 | 37 | use rustc_macros::HashStable; |
c295e0f8 XL |
38 | use rustc_query_system::ich::StableHashingContext; |
39 | use rustc_session::cstore::CrateStoreDyn; | |
6a06907d | 40 | use rustc_span::symbol::{kw, Ident, Symbol}; |
c295e0f8 | 41 | use rustc_span::{sym, Span}; |
6a06907d | 42 | use rustc_target::abi::Align; |
74b04a01 | 43 | |
f9f354fc | 44 | use std::cmp::Ordering; |
94222f64 | 45 | use std::collections::BTreeMap; |
e9174d1e | 46 | use std::hash::{Hash, Hasher}; |
6a06907d XL |
47 | use std::ops::ControlFlow; |
48 | use std::{fmt, ptr, str}; | |
54a0048b | 49 | |
60c5eb7d | 50 | pub use crate::ty::diagnostics::*; |
5869c6ff XL |
51 | pub use rustc_type_ir::InferTy::*; |
52 | pub use rustc_type_ir::*; | |
e9174d1e | 53 | |
3b2f2976 XL |
54 | pub use self::binding::BindingMode; |
55 | pub use self::binding::BindingMode::*; | |
94222f64 XL |
56 | pub use self::closure::{ |
57 | is_ancestor_or_same_capture, place_to_string_for_capture, BorrowKind, CaptureInfo, | |
58 | CapturedPlace, ClosureKind, MinCaptureInformationMap, MinCaptureList, | |
59 | RootVariableMinCaptureList, UpvarBorrow, UpvarCapture, UpvarCaptureMap, UpvarId, UpvarListMap, | |
60 | UpvarPath, CAPTURE_STRUCT_LOCAL, | |
61 | }; | |
cdc7bbd5 | 62 | pub use self::consts::{Const, ConstInt, ConstKind, InferConst, ScalarInt, Unevaluated, ValTree}; |
0731742a | 63 | pub use self::context::{ |
6a06907d XL |
64 | tls, CanonicalUserType, CanonicalUserTypeAnnotation, CanonicalUserTypeAnnotations, |
65 | CtxtInterners, DelaySpanBugEmitted, FreeRegionInfo, GeneratorInteriorTypeCause, GlobalCtxt, | |
136023e0 | 66 | Lift, OnDiskCache, TyCtxt, TypeckResults, UserType, UserTypeAnnotationIndex, |
0731742a | 67 | }; |
cc61c64b | 68 | pub use self::instance::{Instance, InstanceDef}; |
f9f354fc | 69 | pub use self::list::List; |
6a06907d XL |
70 | pub use self::sty::BoundRegionKind::*; |
71 | pub use self::sty::RegionKind::*; | |
72 | pub use self::sty::TyKind::*; | |
73 | pub use self::sty::{ | |
cdc7bbd5 XL |
74 | Binder, BoundRegion, BoundRegionKind, BoundTy, BoundTyKind, BoundVar, BoundVariableKind, |
75 | CanonicalPolyFnSig, ClosureSubsts, ClosureSubstsParts, ConstVid, EarlyBoundRegion, | |
76 | ExistentialPredicate, ExistentialProjection, ExistentialTraitRef, FnSig, FreeRegion, GenSig, | |
77 | GeneratorSubsts, GeneratorSubstsParts, ParamConst, ParamTy, PolyExistentialProjection, | |
78 | PolyExistentialTraitRef, PolyFnSig, PolyGenSig, PolyTraitRef, ProjectionTy, Region, RegionKind, | |
17df50a5 | 79 | RegionVid, TraitRef, TyKind, TypeAndMut, UpvarSubsts, VarianceDiagInfo, VarianceDiagMutKind, |
6a06907d | 80 | }; |
7cac9316 | 81 | pub use self::trait_def::TraitDef; |
9cc50fc6 | 82 | |
3dfed10e | 83 | pub mod _match; |
e9174d1e | 84 | pub mod adjustment; |
3b2f2976 | 85 | pub mod binding; |
e9174d1e | 86 | pub mod cast; |
abe05a73 | 87 | pub mod codec; |
dfeec247 | 88 | pub mod error; |
e9174d1e | 89 | pub mod fast_reject; |
48663c56 | 90 | pub mod flags; |
e9174d1e | 91 | pub mod fold; |
32a655c1 | 92 | pub mod inhabitedness; |
54a0048b | 93 | pub mod layout; |
dfeec247 | 94 | pub mod normalize_erasing_regions; |
532ac7d7 | 95 | pub mod print; |
94b46f34 | 96 | pub mod query; |
e9174d1e | 97 | pub mod relate; |
54a0048b | 98 | pub mod subst; |
9cc50fc6 | 99 | pub mod trait_def; |
e9174d1e | 100 | pub mod util; |
136023e0 | 101 | pub mod vtable; |
dfeec247 | 102 | pub mod walk; |
e9174d1e | 103 | |
6a06907d XL |
104 | mod adt; |
105 | mod assoc; | |
106 | mod closure; | |
f035d41b | 107 | mod consts; |
e9174d1e | 108 | mod context; |
dfeec247 | 109 | mod diagnostics; |
6a06907d XL |
110 | mod erase_regions; |
111 | mod generics; | |
c295e0f8 | 112 | mod impls_ty; |
cc61c64b | 113 | mod instance; |
f9f354fc | 114 | mod list; |
e9174d1e SL |
115 | mod structural_impls; |
116 | mod sty; | |
117 | ||
e9174d1e SL |
118 | // Data types |
119 | ||
136023e0 | 120 | #[derive(Debug)] |
e74abb32 | 121 | pub struct ResolverOutputs { |
ba9703b0 | 122 | pub definitions: rustc_hir::definitions::Definitions, |
e74abb32 | 123 | pub cstore: Box<CrateStoreDyn>, |
29967ef6 | 124 | pub visibilities: FxHashMap<LocalDefId, Visibility>, |
f9f354fc | 125 | pub extern_crate_map: FxHashMap<LocalDefId, CrateNum>, |
f9f354fc XL |
126 | pub maybe_unused_trait_imports: FxHashSet<LocalDefId>, |
127 | pub maybe_unused_extern_crates: Vec<(LocalDefId, Span)>, | |
c295e0f8 | 128 | pub export_map: ExportMap, |
f9f354fc | 129 | pub glob_map: FxHashMap<LocalDefId, FxHashSet<Symbol>>, |
0bf4aa26 XL |
130 | /// Extern prelude entries. The value is `true` if the entry was introduced |
131 | /// via `extern crate` item and not `--extern` option or compiler built-in. | |
f9f354fc | 132 | pub extern_prelude: FxHashMap<Symbol, bool>, |
cdc7bbd5 | 133 | pub main_def: Option<MainDefinition>, |
94222f64 XL |
134 | pub trait_impls: BTreeMap<DefId, Vec<LocalDefId>>, |
135 | /// A list of proc macro LocalDefIds, written out in the order in which | |
136 | /// they are declared in the static array generated by proc_macro_harness. | |
137 | pub proc_macros: Vec<LocalDefId>, | |
c295e0f8 XL |
138 | /// Mapping from ident span to path span for paths that don't exist as written, but that |
139 | /// exist under `std`. For example, wrote `str::from_utf8` instead of `std::str::from_utf8`. | |
140 | pub confused_type_with_std_module: FxHashMap<Span, Span>, | |
cdc7bbd5 XL |
141 | } |
142 | ||
136023e0 | 143 | #[derive(Clone, Copy, Debug)] |
cdc7bbd5 XL |
144 | pub struct MainDefinition { |
145 | pub res: Res<ast::NodeId>, | |
146 | pub is_import: bool, | |
147 | pub span: Span, | |
148 | } | |
149 | ||
150 | impl MainDefinition { | |
151 | pub fn opt_fn_def_id(self) -> Option<DefId> { | |
152 | if let Res::Def(DefKind::Fn, def_id) = self.res { Some(def_id) } else { None } | |
153 | } | |
e9174d1e SL |
154 | } |
155 | ||
54a0048b SL |
156 | /// The "header" of an impl is everything outside the body: a Self type, a trait |
157 | /// ref (in the case of a trait impl), and a set of predicates (from the | |
9fa01778 | 158 | /// bounds / where-clauses). |
60c5eb7d | 159 | #[derive(Clone, Debug, TypeFoldable)] |
54a0048b SL |
160 | pub struct ImplHeader<'tcx> { |
161 | pub impl_def_id: DefId, | |
162 | pub self_ty: Ty<'tcx>, | |
163 | pub trait_ref: Option<TraitRef<'tcx>>, | |
164 | pub predicates: Vec<Predicate<'tcx>>, | |
165 | } | |
166 | ||
5869c6ff | 167 | #[derive(Copy, Clone, PartialEq, TyEncodable, TyDecodable, HashStable, Debug)] |
e74abb32 XL |
168 | pub enum ImplPolarity { |
169 | /// `impl Trait for Type` | |
170 | Positive, | |
171 | /// `impl !Trait for Type` | |
172 | Negative, | |
173 | /// `#[rustc_reservation_impl] impl Trait for Type` | |
174 | /// | |
175 | /// This is a "stability hack", not a real Rust feature. | |
176 | /// See #64631 for details. | |
177 | Reservation, | |
178 | } | |
179 | ||
3dfed10e | 180 | #[derive(Clone, Debug, PartialEq, Eq, Copy, Hash, TyEncodable, TyDecodable, HashStable)] |
54a0048b SL |
181 | pub enum Visibility { |
182 | /// Visible everywhere (including in other crates). | |
183 | Public, | |
184 | /// Visible only in the given crate-local module. | |
32a655c1 | 185 | Restricted(DefId), |
54a0048b | 186 | /// Not visible anywhere in the local crate. This is the visibility of private external items. |
32a655c1 | 187 | Invisible, |
54a0048b SL |
188 | } |
189 | ||
94222f64 XL |
190 | #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, HashStable, TyEncodable, TyDecodable)] |
191 | pub enum BoundConstness { | |
192 | /// `T: Trait` | |
193 | NotConst, | |
194 | /// `T: ~const Trait` | |
195 | /// | |
196 | /// Requires resolving to const only when we are in a const context. | |
197 | ConstIfConst, | |
198 | } | |
199 | ||
200 | impl fmt::Display for BoundConstness { | |
201 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { | |
202 | match self { | |
203 | Self::NotConst => f.write_str("normal"), | |
204 | Self::ConstIfConst => f.write_str("`~const`"), | |
205 | } | |
206 | } | |
207 | } | |
208 | ||
136023e0 XL |
209 | #[derive( |
210 | Clone, | |
211 | Debug, | |
212 | PartialEq, | |
213 | Eq, | |
214 | Copy, | |
215 | Hash, | |
216 | TyEncodable, | |
217 | TyDecodable, | |
218 | HashStable, | |
219 | TypeFoldable | |
220 | )] | |
221 | pub struct ClosureSizeProfileData<'tcx> { | |
222 | /// Tuple containing the types of closure captures before the feature `capture_disjoint_fields` | |
223 | pub before_feature_tys: Ty<'tcx>, | |
224 | /// Tuple containing the types of closure captures after the feature `capture_disjoint_fields` | |
225 | pub after_feature_tys: Ty<'tcx>, | |
226 | } | |
227 | ||
32a655c1 SL |
228 | pub trait DefIdTree: Copy { |
229 | fn parent(self, id: DefId) -> Option<DefId>; | |
a7813a04 | 230 | |
32a655c1 SL |
231 | fn is_descendant_of(self, mut descendant: DefId, ancestor: DefId) -> bool { |
232 | if descendant.krate != ancestor.krate { | |
233 | return false; | |
234 | } | |
235 | ||
236 | while descendant != ancestor { | |
237 | match self.parent(descendant) { | |
238 | Some(parent) => descendant = parent, | |
239 | None => return false, | |
a7813a04 | 240 | } |
a7813a04 XL |
241 | } |
242 | true | |
243 | } | |
244 | } | |
245 | ||
dc9dc135 | 246 | impl<'tcx> DefIdTree for TyCtxt<'tcx> { |
32a655c1 | 247 | fn parent(self, id: DefId) -> Option<DefId> { |
74b04a01 | 248 | self.def_key(id).parent.map(|index| DefId { index, ..id }) |
32a655c1 SL |
249 | } |
250 | } | |
251 | ||
54a0048b | 252 | impl Visibility { |
dfeec247 | 253 | pub fn from_hir(visibility: &hir::Visibility<'_>, id: hir::HirId, tcx: TyCtxt<'_>) -> Self { |
8faf50e0 XL |
254 | match visibility.node { |
255 | hir::VisibilityKind::Public => Visibility::Public, | |
256 | hir::VisibilityKind::Crate(_) => Visibility::Restricted(DefId::local(CRATE_DEF_INDEX)), | |
48663c56 | 257 | hir::VisibilityKind::Restricted { ref path, .. } => match path.res { |
a7813a04 XL |
258 | // If there is no resolution, `resolve` will have already reported an error, so |
259 | // assume that the visibility is public to avoid reporting more privacy errors. | |
48663c56 | 260 | Res::Err => Visibility::Public, |
32a655c1 | 261 | def => Visibility::Restricted(def.def_id()), |
a7813a04 | 262 | }, |
ba9703b0 XL |
263 | hir::VisibilityKind::Inherited => { |
264 | Visibility::Restricted(tcx.parent_module(id).to_def_id()) | |
265 | } | |
54a0048b SL |
266 | } |
267 | } | |
268 | ||
a1dfa0c6 | 269 | /// Returns `true` if an item with this visibility is accessible from the given block. |
32a655c1 | 270 | pub fn is_accessible_from<T: DefIdTree>(self, module: DefId, tree: T) -> bool { |
54a0048b SL |
271 | let restriction = match self { |
272 | // Public items are visible everywhere. | |
273 | Visibility::Public => return true, | |
274 | // Private items from other crates are visible nowhere. | |
32a655c1 | 275 | Visibility::Invisible => return false, |
54a0048b | 276 | // Restricted items are visible in an arbitrary local module. |
32a655c1 | 277 | Visibility::Restricted(other) if other.krate != module.krate => return false, |
54a0048b SL |
278 | Visibility::Restricted(module) => module, |
279 | }; | |
280 | ||
32a655c1 | 281 | tree.is_descendant_of(module, restriction) |
54a0048b SL |
282 | } |
283 | ||
a1dfa0c6 | 284 | /// Returns `true` if this visibility is at least as accessible as the given visibility |
32a655c1 | 285 | pub fn is_at_least<T: DefIdTree>(self, vis: Visibility, tree: T) -> bool { |
54a0048b SL |
286 | let vis_restriction = match vis { |
287 | Visibility::Public => return self == Visibility::Public, | |
32a655c1 | 288 | Visibility::Invisible => return true, |
54a0048b SL |
289 | Visibility::Restricted(module) => module, |
290 | }; | |
291 | ||
a7813a04 | 292 | self.is_accessible_from(vis_restriction, tree) |
54a0048b | 293 | } |
ff7c6d11 | 294 | |
a1dfa0c6 | 295 | // Returns `true` if this item is visible anywhere in the local crate. |
ff7c6d11 XL |
296 | pub fn is_visible_locally(self) -> bool { |
297 | match self { | |
298 | Visibility::Public => true, | |
299 | Visibility::Restricted(def_id) => def_id.is_local(), | |
300 | Visibility::Invisible => false, | |
301 | } | |
302 | } | |
54a0048b SL |
303 | } |
304 | ||
7cac9316 XL |
305 | /// The crate variances map is computed during typeck and contains the |
306 | /// variance of every item in the local crate. You should not use it | |
307 | /// directly, because to do so will make your pass dependent on the | |
308 | /// HIR of every item in the local crate. Instead, use | |
309 | /// `tcx.variances_of()` to get the variance for a *particular* | |
310 | /// item. | |
5869c6ff | 311 | #[derive(HashStable, Debug)] |
48663c56 | 312 | pub struct CrateVariancesMap<'tcx> { |
7cac9316 | 313 | /// For each item with generics, maps to a vector of the variance |
9fa01778 | 314 | /// of its generics. If an item has no generics, it will have no |
7cac9316 | 315 | /// entry. |
48663c56 | 316 | pub variances: FxHashMap<DefId, &'tcx [ty::Variance]>, |
7cac9316 XL |
317 | } |
318 | ||
e9174d1e SL |
319 | // Contains information needed to resolve types and (in the future) look up |
320 | // the types of AST nodes. | |
321 | #[derive(Copy, Clone, PartialEq, Eq, Hash)] | |
322 | pub struct CReaderCacheKey { | |
17df50a5 | 323 | pub cnum: Option<CrateNum>, |
e9174d1e | 324 | pub pos: usize, |
e9174d1e SL |
325 | } |
326 | ||
e1599b0c | 327 | #[allow(rustc::usage_of_ty_tykind)] |
e9174d1e | 328 | pub struct TyS<'tcx> { |
1b1a35ee XL |
329 | /// This field shouldn't be used directly and may be removed in the future. |
330 | /// Use `TyS::kind()` instead. | |
331 | kind: TyKind<'tcx>, | |
332 | /// This field shouldn't be used directly and may be removed in the future. | |
333 | /// Use `TyS::flags()` instead. | |
334 | flags: TypeFlags, | |
e9174d1e | 335 | |
94b46f34 XL |
336 | /// This is a kind of confusing thing: it stores the smallest |
337 | /// binder such that | |
338 | /// | |
339 | /// (a) the binder itself captures nothing but | |
340 | /// (b) all the late-bound things within the type are captured | |
341 | /// by some sub-binder. | |
342 | /// | |
343 | /// So, for a type without any late-bound things, like `u32`, this | |
0731742a | 344 | /// will be *innermost*, because that is the innermost binder that |
94b46f34 | 345 | /// captures nothing. But for a type `&'D u32`, where `'D` is a |
9fa01778 | 346 | /// late-bound region with De Bruijn index `D`, this would be `D + 1` |
0731742a XL |
347 | /// -- the binder itself does not capture `D`, but `D` is captured |
348 | /// by an inner binder. | |
94b46f34 | 349 | /// |
0731742a | 350 | /// We call this concept an "exclusive" binder `D` because all |
9fa01778 | 351 | /// De Bruijn indices within the type are contained within `0..D` |
0731742a | 352 | /// (exclusive). |
94b46f34 XL |
353 | outer_exclusive_binder: ty::DebruijnIndex, |
354 | } | |
355 | ||
fc512014 XL |
356 | impl<'tcx> TyS<'tcx> { |
357 | /// A constructor used only for internal testing. | |
358 | #[allow(rustc::usage_of_ty_tykind)] | |
359 | pub fn make_for_test( | |
360 | kind: TyKind<'tcx>, | |
361 | flags: TypeFlags, | |
362 | outer_exclusive_binder: ty::DebruijnIndex, | |
363 | ) -> TyS<'tcx> { | |
364 | TyS { kind, flags, outer_exclusive_binder } | |
365 | } | |
366 | } | |
367 | ||
a1dfa0c6 | 368 | // `TyS` is used a lot. Make sure it doesn't unintentionally get bigger. |
6a06907d | 369 | #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))] |
cdc7bbd5 | 370 | static_assert_size!(TyS<'_>, 40); |
a1dfa0c6 | 371 | |
94b46f34 XL |
372 | impl<'tcx> Ord for TyS<'tcx> { |
373 | fn cmp(&self, other: &TyS<'tcx>) -> Ordering { | |
1b1a35ee | 374 | self.kind().cmp(other.kind()) |
94b46f34 XL |
375 | } |
376 | } | |
377 | ||
378 | impl<'tcx> PartialOrd for TyS<'tcx> { | |
379 | fn partial_cmp(&self, other: &TyS<'tcx>) -> Option<Ordering> { | |
1b1a35ee | 380 | Some(self.kind().cmp(other.kind())) |
94b46f34 | 381 | } |
e9174d1e SL |
382 | } |
383 | ||
384 | impl<'tcx> PartialEq for TyS<'tcx> { | |
385 | #[inline] | |
386 | fn eq(&self, other: &TyS<'tcx>) -> bool { | |
8faf50e0 | 387 | ptr::eq(self, other) |
e9174d1e SL |
388 | } |
389 | } | |
390 | impl<'tcx> Eq for TyS<'tcx> {} | |
391 | ||
392 | impl<'tcx> Hash for TyS<'tcx> { | |
393 | fn hash<H: Hasher>(&self, s: &mut H) { | |
0bf4aa26 | 394 | (self as *const TyS<'_>).hash(s) |
e9174d1e SL |
395 | } |
396 | } | |
397 | ||
f035d41b | 398 | impl<'a, 'tcx> HashStable<StableHashingContext<'a>> for TyS<'tcx> { |
e74abb32 | 399 | fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) { |
cc61c64b | 400 | let ty::TyS { |
e74abb32 | 401 | ref kind, |
cc61c64b XL |
402 | |
403 | // The other fields just provide fast access to information that is | |
e74abb32 | 404 | // also contained in `kind`, so no need to hash them. |
cc61c64b | 405 | flags: _, |
94b46f34 XL |
406 | |
407 | outer_exclusive_binder: _, | |
cc61c64b XL |
408 | } = *self; |
409 | ||
e74abb32 | 410 | kind.hash_stable(hcx, hasher); |
cc61c64b XL |
411 | } |
412 | } | |
413 | ||
e74abb32 | 414 | #[rustc_diagnostic_item = "Ty"] |
e9174d1e SL |
415 | pub type Ty<'tcx> = &'tcx TyS<'tcx>; |
416 | ||
94b46f34 | 417 | impl ty::EarlyBoundRegion { |
b7449926 XL |
418 | /// Does this early bound region have a name? Early bound regions normally |
419 | /// always have names except when using anonymous lifetimes (`'_`). | |
420 | pub fn has_name(&self) -> bool { | |
e74abb32 | 421 | self.name != kw::UnderscoreLifetime |
b7449926 | 422 | } |
94b46f34 | 423 | } |
ea8adc8c | 424 | |
f035d41b XL |
425 | #[derive(Debug)] |
426 | crate struct PredicateInner<'tcx> { | |
cdc7bbd5 | 427 | kind: Binder<'tcx, PredicateKind<'tcx>>, |
f035d41b XL |
428 | flags: TypeFlags, |
429 | /// See the comment for the corresponding field of [TyS]. | |
430 | outer_exclusive_binder: ty::DebruijnIndex, | |
431 | } | |
432 | ||
6a06907d | 433 | #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))] |
cdc7bbd5 | 434 | static_assert_size!(PredicateInner<'_>, 48); |
f035d41b XL |
435 | |
436 | #[derive(Clone, Copy, Lift)] | |
f9f354fc | 437 | pub struct Predicate<'tcx> { |
f035d41b | 438 | inner: &'tcx PredicateInner<'tcx>, |
f9f354fc XL |
439 | } |
440 | ||
441 | impl<'tcx> PartialEq for Predicate<'tcx> { | |
442 | fn eq(&self, other: &Self) -> bool { | |
443 | // `self.kind` is always interned. | |
f035d41b XL |
444 | ptr::eq(self.inner, other.inner) |
445 | } | |
446 | } | |
447 | ||
448 | impl Hash for Predicate<'_> { | |
449 | fn hash<H: Hasher>(&self, s: &mut H) { | |
450 | (self.inner as *const PredicateInner<'_>).hash(s) | |
f9f354fc XL |
451 | } |
452 | } | |
453 | ||
454 | impl<'tcx> Eq for Predicate<'tcx> {} | |
455 | ||
456 | impl<'tcx> Predicate<'tcx> { | |
cdc7bbd5 | 457 | /// Gets the inner `Binder<'tcx, PredicateKind<'tcx>>`. |
6a06907d | 458 | #[inline] |
cdc7bbd5 | 459 | pub fn kind(self) -> Binder<'tcx, PredicateKind<'tcx>> { |
5869c6ff | 460 | self.inner.kind |
3dfed10e | 461 | } |
f035d41b XL |
462 | } |
463 | ||
464 | impl<'a, 'tcx> HashStable<StableHashingContext<'a>> for Predicate<'tcx> { | |
465 | fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) { | |
466 | let PredicateInner { | |
467 | ref kind, | |
468 | ||
469 | // The other fields just provide fast access to information that is | |
470 | // also contained in `kind`, so no need to hash them. | |
471 | flags: _, | |
472 | outer_exclusive_binder: _, | |
473 | } = self.inner; | |
474 | ||
475 | kind.hash_stable(hcx, hasher); | |
f9f354fc XL |
476 | } |
477 | } | |
478 | ||
3dfed10e | 479 | #[derive(Clone, Copy, PartialEq, Eq, Hash, TyEncodable, TyDecodable)] |
60c5eb7d | 480 | #[derive(HashStable, TypeFoldable)] |
f9f354fc | 481 | pub enum PredicateKind<'tcx> { |
dc9dc135 | 482 | /// Corresponds to `where Foo: Bar<A, B, C>`. `Foo` here would be |
e9174d1e | 483 | /// the `Self` type of the trait reference and `A`, `B`, and `C` |
9e0c209e | 484 | /// would be the type parameters. |
94222f64 | 485 | Trait(TraitPredicate<'tcx>), |
e9174d1e | 486 | |
dc9dc135 | 487 | /// `where 'a: 'b` |
3dfed10e | 488 | RegionOutlives(RegionOutlivesPredicate<'tcx>), |
e9174d1e | 489 | |
dc9dc135 | 490 | /// `where T: 'a` |
3dfed10e | 491 | TypeOutlives(TypeOutlivesPredicate<'tcx>), |
e9174d1e | 492 | |
dc9dc135 | 493 | /// `where <T as TraitRef>::Name == X`, approximately. |
a1dfa0c6 | 494 | /// See the `ProjectionPredicate` struct for details. |
3dfed10e | 495 | Projection(ProjectionPredicate<'tcx>), |
e9174d1e | 496 | |
dc9dc135 | 497 | /// No syntax: `T` well-formed. |
f035d41b | 498 | WellFormed(GenericArg<'tcx>), |
e9174d1e | 499 | |
dc9dc135 | 500 | /// Trait must be object-safe. |
e9174d1e | 501 | ObjectSafe(DefId), |
a7813a04 | 502 | |
a1dfa0c6 XL |
503 | /// No direct syntax. May be thought of as `where T: FnFoo<...>` |
504 | /// for some substitutions `...` and `T` being a closure type. | |
9e0c209e | 505 | /// Satisfied (or refuted) once we know the closure's kind. |
e74abb32 | 506 | ClosureKind(DefId, SubstsRef<'tcx>, ClosureKind), |
cc61c64b XL |
507 | |
508 | /// `T1 <: T2` | |
94222f64 XL |
509 | /// |
510 | /// This obligation is created most often when we have two | |
511 | /// unresolved type variables and hence don't have enough | |
512 | /// information to process the subtyping obligation yet. | |
3dfed10e | 513 | Subtype(SubtypePredicate<'tcx>), |
ea8adc8c | 514 | |
94222f64 XL |
515 | /// `T1` coerced to `T2` |
516 | /// | |
517 | /// Like a subtyping obligation, this is created most often | |
518 | /// when we have two unresolved type variables and hence | |
519 | /// don't have enough information to process the coercion | |
520 | /// obligation yet. At the moment, we actually process coercions | |
521 | /// very much like subtyping and don't handle the full coercion | |
522 | /// logic. | |
523 | Coerce(CoercePredicate<'tcx>), | |
524 | ||
ea8adc8c | 525 | /// Constant initializer must evaluate successfully. |
94222f64 | 526 | ConstEvaluatable(ty::Unevaluated<'tcx, ()>), |
f9f354fc XL |
527 | |
528 | /// Constants must be equal. The first component is the const that is expected. | |
529 | ConstEquate(&'tcx Const<'tcx>, &'tcx Const<'tcx>), | |
1b1a35ee XL |
530 | |
531 | /// Represents a type found in the environment that we can use for implied bounds. | |
532 | /// | |
533 | /// Only used for Chalk. | |
534 | TypeWellFormedFromEnv(Ty<'tcx>), | |
e9174d1e SL |
535 | } |
536 | ||
83c7162d XL |
537 | /// The crate outlives map is computed during typeck and contains the |
538 | /// outlives of every item in the local crate. You should not use it | |
539 | /// directly, because to do so will make your pass dependent on the | |
540 | /// HIR of every item in the local crate. Instead, use | |
541 | /// `tcx.inferred_outlives_of()` to get the outlives for a *particular* | |
542 | /// item. | |
5869c6ff | 543 | #[derive(HashStable, Debug)] |
83c7162d XL |
544 | pub struct CratePredicatesMap<'tcx> { |
545 | /// For each struct with outlive bounds, maps to a vector of the | |
546 | /// predicate of its outlive bounds. If an item has no outlives | |
547 | /// bounds, it will have no entry. | |
3dfed10e | 548 | pub predicates: FxHashMap<DefId, &'tcx [(Predicate<'tcx>, Span)]>, |
83c7162d XL |
549 | } |
550 | ||
dc9dc135 | 551 | impl<'tcx> Predicate<'tcx> { |
e9174d1e SL |
552 | /// Performs a substitution suitable for going from a |
553 | /// poly-trait-ref to supertraits that must hold if that | |
554 | /// poly-trait-ref holds. This is slightly different from a normal | |
9fa01778 | 555 | /// substitution in terms of what happens with bound regions. See |
e9174d1e | 556 | /// lengthy comment below for details. |
dc9dc135 | 557 | pub fn subst_supertrait( |
f9f354fc | 558 | self, |
dc9dc135 XL |
559 | tcx: TyCtxt<'tcx>, |
560 | trait_ref: &ty::PolyTraitRef<'tcx>, | |
3dfed10e | 561 | ) -> Predicate<'tcx> { |
e9174d1e SL |
562 | // The interaction between HRTB and supertraits is not entirely |
563 | // obvious. Let me walk you (and myself) through an example. | |
564 | // | |
565 | // Let's start with an easy case. Consider two traits: | |
566 | // | |
a1dfa0c6 | 567 | // trait Foo<'a>: Bar<'a,'a> { } |
e9174d1e SL |
568 | // trait Bar<'b,'c> { } |
569 | // | |
a1dfa0c6 XL |
570 | // Now, if we have a trait reference `for<'x> T: Foo<'x>`, then |
571 | // we can deduce that `for<'x> T: Bar<'x,'x>`. Basically, if we | |
e9174d1e SL |
572 | // knew that `Foo<'x>` (for any 'x) then we also know that |
573 | // `Bar<'x,'x>` (for any 'x). This more-or-less falls out from | |
574 | // normal substitution. | |
575 | // | |
576 | // In terms of why this is sound, the idea is that whenever there | |
577 | // is an impl of `T:Foo<'a>`, it must show that `T:Bar<'a,'a>` | |
578 | // holds. So if there is an impl of `T:Foo<'a>` that applies to | |
579 | // all `'a`, then we must know that `T:Bar<'a,'a>` holds for all | |
580 | // `'a`. | |
581 | // | |
582 | // Another example to be careful of is this: | |
583 | // | |
a1dfa0c6 | 584 | // trait Foo1<'a>: for<'b> Bar1<'a,'b> { } |
e9174d1e SL |
585 | // trait Bar1<'b,'c> { } |
586 | // | |
a1dfa0c6 XL |
587 | // Here, if we have `for<'x> T: Foo1<'x>`, then what do we know? |
588 | // The answer is that we know `for<'x,'b> T: Bar1<'x,'b>`. The | |
e9174d1e | 589 | // reason is similar to the previous example: any impl of |
a1dfa0c6 | 590 | // `T:Foo1<'x>` must show that `for<'b> T: Bar1<'x, 'b>`. So |
e9174d1e SL |
591 | // basically we would want to collapse the bound lifetimes from |
592 | // the input (`trait_ref`) and the supertraits. | |
593 | // | |
594 | // To achieve this in practice is fairly straightforward. Let's | |
595 | // consider the more complicated scenario: | |
596 | // | |
a1dfa0c6 XL |
597 | // - We start out with `for<'x> T: Foo1<'x>`. In this case, `'x` |
598 | // has a De Bruijn index of 1. We want to produce `for<'x,'b> T: Bar1<'x,'b>`, | |
e9174d1e SL |
599 | // where both `'x` and `'b` would have a DB index of 1. |
600 | // The substitution from the input trait-ref is therefore going to be | |
601 | // `'a => 'x` (where `'x` has a DB index of 1). | |
c295e0f8 | 602 | // - The supertrait-ref is `for<'b> Bar1<'a,'b>`, where `'a` is an |
e9174d1e SL |
603 | // early-bound parameter and `'b' is a late-bound parameter with a |
604 | // DB index of 1. | |
605 | // - If we replace `'a` with `'x` from the input, it too will have | |
606 | // a DB index of 1, and thus we'll have `for<'x,'b> Bar1<'x,'b>` | |
607 | // just as we wanted. | |
608 | // | |
609 | // There is only one catch. If we just apply the substitution `'a | |
610 | // => 'x` to `for<'b> Bar1<'a,'b>`, the substitution code will | |
611 | // adjust the DB index because we substituting into a binder (it | |
612 | // tries to be so smart...) resulting in `for<'x> for<'b> | |
613 | // Bar1<'x,'b>` (we have no syntax for this, so use your | |
614 | // imagination). Basically the 'x will have DB index of 2 and 'b | |
615 | // will have DB index of 1. Not quite what we want. So we apply | |
616 | // the substitution to the *contents* of the trait reference, | |
617 | // rather than the trait reference itself (put another way, the | |
618 | // substitution code expects equal binding levels in the values | |
619 | // from the substitution and the value being substituted into, and | |
620 | // this trick achieves that). | |
cdc7bbd5 XL |
621 | |
622 | // Working through the second example: | |
623 | // trait_ref: for<'x> T: Foo1<'^0.0>; substs: [T, '^0.0] | |
624 | // predicate: for<'b> Self: Bar1<'a, '^0.0>; substs: [Self, 'a, '^0.0] | |
625 | // We want to end up with: | |
626 | // for<'x, 'b> T: Bar1<'^0.0, '^0.1> | |
627 | // To do this: | |
628 | // 1) We must shift all bound vars in predicate by the length | |
629 | // of trait ref's bound vars. So, we would end up with predicate like | |
630 | // Self: Bar1<'a, '^0.1> | |
631 | // 2) We can then apply the trait substs to this, ending up with | |
632 | // T: Bar1<'^0.0, '^0.1> | |
633 | // 3) Finally, to create the final bound vars, we concatenate the bound | |
634 | // vars of the trait ref with those of the predicate: | |
635 | // ['x, 'b] | |
636 | let bound_pred = self.kind(); | |
637 | let pred_bound_vars = bound_pred.bound_vars(); | |
638 | let trait_bound_vars = trait_ref.bound_vars(); | |
639 | // 1) Self: Bar1<'a, '^0.0> -> Self: Bar1<'a, '^0.1> | |
640 | let shifted_pred = | |
641 | tcx.shift_bound_var_indices(trait_bound_vars.len(), bound_pred.skip_binder()); | |
642 | // 2) Self: Bar1<'a, '^0.1> -> T: Bar1<'^0.0, '^0.1> | |
643 | let new = shifted_pred.subst(tcx, trait_ref.skip_binder().substs); | |
644 | // 3) ['x] + ['b] -> ['x, 'b] | |
645 | let bound_vars = | |
646 | tcx.mk_bound_variable_kinds(trait_bound_vars.iter().chain(pred_bound_vars)); | |
647 | tcx.reuse_or_mk_predicate(self, ty::Binder::bind_with_vars(new, bound_vars)) | |
e9174d1e SL |
648 | } |
649 | } | |
650 | ||
3dfed10e | 651 | #[derive(Clone, Copy, PartialEq, Eq, Hash, TyEncodable, TyDecodable)] |
60c5eb7d | 652 | #[derive(HashStable, TypeFoldable)] |
e9174d1e | 653 | pub struct TraitPredicate<'tcx> { |
dfeec247 | 654 | pub trait_ref: TraitRef<'tcx>, |
94222f64 XL |
655 | |
656 | pub constness: BoundConstness, | |
e9174d1e | 657 | } |
a1dfa0c6 | 658 | |
cdc7bbd5 | 659 | pub type PolyTraitPredicate<'tcx> = ty::Binder<'tcx, TraitPredicate<'tcx>>; |
e9174d1e SL |
660 | |
661 | impl<'tcx> TraitPredicate<'tcx> { | |
f9f354fc | 662 | pub fn def_id(self) -> DefId { |
e9174d1e SL |
663 | self.trait_ref.def_id |
664 | } | |
665 | ||
f9f354fc | 666 | pub fn self_ty(self) -> Ty<'tcx> { |
e9174d1e SL |
667 | self.trait_ref.self_ty() |
668 | } | |
669 | } | |
670 | ||
671 | impl<'tcx> PolyTraitPredicate<'tcx> { | |
f9f354fc | 672 | pub fn def_id(self) -> DefId { |
416331ca | 673 | // Ok to skip binder since trait `DefId` does not care about regions. |
83c7162d | 674 | self.skip_binder().def_id() |
e9174d1e | 675 | } |
fc512014 | 676 | |
cdc7bbd5 | 677 | pub fn self_ty(self) -> ty::Binder<'tcx, Ty<'tcx>> { |
fc512014 XL |
678 | self.map_bound(|trait_ref| trait_ref.self_ty()) |
679 | } | |
e9174d1e SL |
680 | } |
681 | ||
3dfed10e | 682 | #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug, TyEncodable, TyDecodable)] |
60c5eb7d | 683 | #[derive(HashStable, TypeFoldable)] |
dc9dc135 | 684 | pub struct OutlivesPredicate<A, B>(pub A, pub B); // `A: B` |
dc9dc135 XL |
685 | pub type RegionOutlivesPredicate<'tcx> = OutlivesPredicate<ty::Region<'tcx>, ty::Region<'tcx>>; |
686 | pub type TypeOutlivesPredicate<'tcx> = OutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>>; | |
cdc7bbd5 XL |
687 | pub type PolyRegionOutlivesPredicate<'tcx> = ty::Binder<'tcx, RegionOutlivesPredicate<'tcx>>; |
688 | pub type PolyTypeOutlivesPredicate<'tcx> = ty::Binder<'tcx, TypeOutlivesPredicate<'tcx>>; | |
e9174d1e | 689 | |
94222f64 XL |
690 | /// Encodes that `a` must be a subtype of `b`. The `a_is_expected` flag indicates |
691 | /// whether the `a` type is the type that we should label as "expected" when | |
692 | /// presenting user diagnostics. | |
3dfed10e | 693 | #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug, TyEncodable, TyDecodable)] |
60c5eb7d | 694 | #[derive(HashStable, TypeFoldable)] |
cc61c64b XL |
695 | pub struct SubtypePredicate<'tcx> { |
696 | pub a_is_expected: bool, | |
697 | pub a: Ty<'tcx>, | |
dfeec247 | 698 | pub b: Ty<'tcx>, |
cc61c64b | 699 | } |
cdc7bbd5 | 700 | pub type PolySubtypePredicate<'tcx> = ty::Binder<'tcx, SubtypePredicate<'tcx>>; |
cc61c64b | 701 | |
94222f64 XL |
702 | /// Encodes that we have to coerce *from* the `a` type to the `b` type. |
703 | #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug, TyEncodable, TyDecodable)] | |
704 | #[derive(HashStable, TypeFoldable)] | |
705 | pub struct CoercePredicate<'tcx> { | |
706 | pub a: Ty<'tcx>, | |
707 | pub b: Ty<'tcx>, | |
708 | } | |
709 | pub type PolyCoercePredicate<'tcx> = ty::Binder<'tcx, CoercePredicate<'tcx>>; | |
710 | ||
e9174d1e SL |
711 | /// This kind of predicate has no *direct* correspondent in the |
712 | /// syntax, but it roughly corresponds to the syntactic forms: | |
713 | /// | |
9fa01778 | 714 | /// 1. `T: TraitRef<..., Item = Type>` |
e9174d1e SL |
715 | /// 2. `<T as TraitRef<...>>::Item == Type` (NYI) |
716 | /// | |
717 | /// In particular, form #1 is "desugared" to the combination of a | |
a1dfa0c6 | 718 | /// normal trait predicate (`T: TraitRef<...>`) and one of these |
e9174d1e | 719 | /// predicates. Form #2 is a broader form in that it also permits |
ff7c6d11 XL |
720 | /// equality between arbitrary types. Processing an instance of |
721 | /// Form #2 eventually yields one of these `ProjectionPredicate` | |
e9174d1e | 722 | /// instances to normalize the LHS. |
3dfed10e | 723 | #[derive(Copy, Clone, PartialEq, Eq, Hash, TyEncodable, TyDecodable)] |
60c5eb7d | 724 | #[derive(HashStable, TypeFoldable)] |
e9174d1e SL |
725 | pub struct ProjectionPredicate<'tcx> { |
726 | pub projection_ty: ProjectionTy<'tcx>, | |
727 | pub ty: Ty<'tcx>, | |
728 | } | |
729 | ||
cdc7bbd5 | 730 | pub type PolyProjectionPredicate<'tcx> = Binder<'tcx, ProjectionPredicate<'tcx>>; |
e9174d1e SL |
731 | |
732 | impl<'tcx> PolyProjectionPredicate<'tcx> { | |
6a06907d XL |
733 | /// Returns the `DefId` of the trait of the associated item being projected. |
734 | #[inline] | |
735 | pub fn trait_def_id(&self, tcx: TyCtxt<'tcx>) -> DefId { | |
736 | self.skip_binder().projection_ty.trait_def_id(tcx) | |
737 | } | |
738 | ||
6a06907d XL |
739 | /// Get the [PolyTraitRef] required for this projection to be well formed. |
740 | /// Note that for generic associated types the predicates of the associated | |
741 | /// type also need to be checked. | |
a1dfa0c6 | 742 | #[inline] |
6a06907d | 743 | pub fn required_poly_trait_ref(&self, tcx: TyCtxt<'tcx>) -> PolyTraitRef<'tcx> { |
a1dfa0c6 XL |
744 | // Note: unlike with `TraitRef::to_poly_trait_ref()`, |
745 | // `self.0.trait_ref` is permitted to have escaping regions. | |
041b39d2 XL |
746 | // This is because here `self` has a `Binder` and so does our |
747 | // return value, so we are preserving the number of binding | |
748 | // levels. | |
83c7162d | 749 | self.map_bound(|predicate| predicate.projection_ty.trait_ref(tcx)) |
e9174d1e | 750 | } |
3b2f2976 | 751 | |
cdc7bbd5 | 752 | pub fn ty(&self) -> Binder<'tcx, Ty<'tcx>> { |
83c7162d XL |
753 | self.map_bound(|predicate| predicate.ty) |
754 | } | |
755 | ||
a1dfa0c6 | 756 | /// The `DefId` of the `TraitItem` for the associated type. |
83c7162d | 757 | /// |
a1dfa0c6 XL |
758 | /// Note that this is not the `DefId` of the `TraitRef` containing this |
759 | /// associated type, which is in `tcx.associated_item(projection_def_id()).container`. | |
83c7162d | 760 | pub fn projection_def_id(&self) -> DefId { |
416331ca | 761 | // Ok to skip binder since trait `DefId` does not care about regions. |
83c7162d | 762 | self.skip_binder().projection_ty.item_def_id |
3b2f2976 | 763 | } |
e9174d1e SL |
764 | } |
765 | ||
766 | pub trait ToPolyTraitRef<'tcx> { | |
767 | fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx>; | |
768 | } | |
769 | ||
e9174d1e SL |
770 | impl<'tcx> ToPolyTraitRef<'tcx> for PolyTraitPredicate<'tcx> { |
771 | fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx> { | |
7453a54e | 772 | self.map_bound_ref(|trait_pred| trait_pred.trait_ref) |
e9174d1e SL |
773 | } |
774 | } | |
775 | ||
e9174d1e | 776 | pub trait ToPredicate<'tcx> { |
f035d41b | 777 | fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx>; |
f9f354fc XL |
778 | } |
779 | ||
cdc7bbd5 | 780 | impl ToPredicate<'tcx> for Binder<'tcx, PredicateKind<'tcx>> { |
f9f354fc | 781 | #[inline(always)] |
f035d41b XL |
782 | fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> { |
783 | tcx.mk_predicate(self) | |
f9f354fc | 784 | } |
e9174d1e SL |
785 | } |
786 | ||
dfeec247 | 787 | impl<'tcx> ToPredicate<'tcx> for ConstnessAnd<PolyTraitRef<'tcx>> { |
f035d41b | 788 | fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> { |
cdc7bbd5 XL |
789 | self.value |
790 | .map_bound(|trait_ref| { | |
94222f64 | 791 | PredicateKind::Trait(ty::TraitPredicate { trait_ref, constness: self.constness }) |
cdc7bbd5 XL |
792 | }) |
793 | .to_predicate(tcx) | |
dfeec247 XL |
794 | } |
795 | } | |
796 | ||
94222f64 | 797 | impl<'tcx> ToPredicate<'tcx> for PolyTraitPredicate<'tcx> { |
f035d41b | 798 | fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> { |
94222f64 | 799 | self.map_bound(PredicateKind::Trait).to_predicate(tcx) |
e9174d1e SL |
800 | } |
801 | } | |
802 | ||
9e0c209e | 803 | impl<'tcx> ToPredicate<'tcx> for PolyRegionOutlivesPredicate<'tcx> { |
f035d41b | 804 | fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> { |
5869c6ff | 805 | self.map_bound(PredicateKind::RegionOutlives).to_predicate(tcx) |
e9174d1e SL |
806 | } |
807 | } | |
808 | ||
809 | impl<'tcx> ToPredicate<'tcx> for PolyTypeOutlivesPredicate<'tcx> { | |
f035d41b | 810 | fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> { |
5869c6ff | 811 | self.map_bound(PredicateKind::TypeOutlives).to_predicate(tcx) |
e9174d1e SL |
812 | } |
813 | } | |
814 | ||
815 | impl<'tcx> ToPredicate<'tcx> for PolyProjectionPredicate<'tcx> { | |
f035d41b | 816 | fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> { |
5869c6ff | 817 | self.map_bound(PredicateKind::Projection).to_predicate(tcx) |
e9174d1e SL |
818 | } |
819 | } | |
820 | ||
821 | impl<'tcx> Predicate<'tcx> { | |
fc512014 | 822 | pub fn to_opt_poly_trait_ref(self) -> Option<ConstnessAnd<PolyTraitRef<'tcx>>> { |
5869c6ff | 823 | let predicate = self.kind(); |
fc512014 | 824 | match predicate.skip_binder() { |
94222f64 XL |
825 | PredicateKind::Trait(t) => { |
826 | Some(ConstnessAnd { constness: t.constness, value: predicate.rebind(t.trait_ref) }) | |
fc512014 | 827 | } |
5869c6ff XL |
828 | PredicateKind::Projection(..) |
829 | | PredicateKind::Subtype(..) | |
94222f64 | 830 | | PredicateKind::Coerce(..) |
5869c6ff XL |
831 | | PredicateKind::RegionOutlives(..) |
832 | | PredicateKind::WellFormed(..) | |
833 | | PredicateKind::ObjectSafe(..) | |
834 | | PredicateKind::ClosureKind(..) | |
835 | | PredicateKind::TypeOutlives(..) | |
836 | | PredicateKind::ConstEvaluatable(..) | |
837 | | PredicateKind::ConstEquate(..) | |
838 | | PredicateKind::TypeWellFormedFromEnv(..) => None, | |
e9174d1e SL |
839 | } |
840 | } | |
abe05a73 | 841 | |
f9f354fc | 842 | pub fn to_opt_type_outlives(self) -> Option<PolyTypeOutlivesPredicate<'tcx>> { |
5869c6ff | 843 | let predicate = self.kind(); |
fc512014 | 844 | match predicate.skip_binder() { |
5869c6ff XL |
845 | PredicateKind::TypeOutlives(data) => Some(predicate.rebind(data)), |
846 | PredicateKind::Trait(..) | |
847 | | PredicateKind::Projection(..) | |
848 | | PredicateKind::Subtype(..) | |
94222f64 | 849 | | PredicateKind::Coerce(..) |
5869c6ff XL |
850 | | PredicateKind::RegionOutlives(..) |
851 | | PredicateKind::WellFormed(..) | |
852 | | PredicateKind::ObjectSafe(..) | |
853 | | PredicateKind::ClosureKind(..) | |
854 | | PredicateKind::ConstEvaluatable(..) | |
855 | | PredicateKind::ConstEquate(..) | |
856 | | PredicateKind::TypeWellFormedFromEnv(..) => None, | |
abe05a73 XL |
857 | } |
858 | } | |
e9174d1e SL |
859 | } |
860 | ||
861 | /// Represents the bounds declared on a particular set of type | |
9fa01778 | 862 | /// parameters. Should eventually be generalized into a flag list of |
94222f64 | 863 | /// where-clauses. You can obtain an `InstantiatedPredicates` list from a |
e9174d1e SL |
864 | /// `GenericPredicates` by using the `instantiate` method. Note that this method |
865 | /// reflects an important semantic invariant of `InstantiatedPredicates`: while | |
866 | /// the `GenericPredicates` are expressed in terms of the bound type | |
867 | /// parameters of the impl/trait/whatever, an `InstantiatedPredicates` instance | |
868 | /// represented a set of bounds for some particular instantiation, | |
869 | /// meaning that the generic parameters have been substituted with | |
870 | /// their values. | |
871 | /// | |
872 | /// Example: | |
873 | /// | |
dc9dc135 | 874 | /// struct Foo<T, U: Bar<T>> { ... } |
e9174d1e SL |
875 | /// |
876 | /// Here, the `GenericPredicates` for `Foo` would contain a list of bounds like | |
9fa01778 | 877 | /// `[[], [U:Bar<T>]]`. Now if there were some particular reference |
e9174d1e SL |
878 | /// like `Foo<isize,usize>`, then the `InstantiatedPredicates` would be `[[], |
879 | /// [usize:Bar<isize>]]`. | |
60c5eb7d | 880 | #[derive(Clone, Debug, TypeFoldable)] |
e9174d1e | 881 | pub struct InstantiatedPredicates<'tcx> { |
9e0c209e | 882 | pub predicates: Vec<Predicate<'tcx>>, |
74b04a01 | 883 | pub spans: Vec<Span>, |
e9174d1e SL |
884 | } |
885 | ||
886 | impl<'tcx> InstantiatedPredicates<'tcx> { | |
887 | pub fn empty() -> InstantiatedPredicates<'tcx> { | |
74b04a01 | 888 | InstantiatedPredicates { predicates: vec![], spans: vec![] } |
e9174d1e SL |
889 | } |
890 | ||
891 | pub fn is_empty(&self) -> bool { | |
892 | self.predicates.is_empty() | |
893 | } | |
894 | } | |
895 | ||
136023e0 | 896 | #[derive(Copy, Clone, Debug, PartialEq, Eq, HashStable, TyEncodable, TyDecodable, TypeFoldable)] |
17df50a5 XL |
897 | pub struct OpaqueTypeKey<'tcx> { |
898 | pub def_id: DefId, | |
899 | pub substs: SubstsRef<'tcx>, | |
900 | } | |
901 | ||
e74abb32 | 902 | rustc_index::newtype_index! { |
532ac7d7 XL |
903 | /// "Universes" are used during type- and trait-checking in the |
904 | /// presence of `for<..>` binders to control what sets of names are | |
905 | /// visible. Universes are arranged into a tree: the root universe | |
906 | /// contains names that are always visible. Each child then adds a new | |
907 | /// set of names that are visible, in addition to those of its parent. | |
908 | /// We say that the child universe "extends" the parent universe with | |
909 | /// new names. | |
910 | /// | |
911 | /// To make this more concrete, consider this program: | |
912 | /// | |
913 | /// ``` | |
914 | /// struct Foo { } | |
915 | /// fn bar<T>(x: T) { | |
916 | /// let y: for<'a> fn(&'a u8, Foo) = ...; | |
917 | /// } | |
918 | /// ``` | |
919 | /// | |
920 | /// The struct name `Foo` is in the root universe U0. But the type | |
921 | /// parameter `T`, introduced on `bar`, is in an extended universe U1 | |
922 | /// -- i.e., within `bar`, we can name both `T` and `Foo`, but outside | |
923 | /// of `bar`, we cannot name `T`. Then, within the type of `y`, the | |
924 | /// region `'a` is in a universe U2 that extends U1, because we can | |
925 | /// name it inside the fn type but not outside. | |
926 | /// | |
927 | /// Universes are used to do type- and trait-checking around these | |
928 | /// "forall" binders (also called **universal quantification**). The | |
929 | /// idea is that when, in the body of `bar`, we refer to `T` as a | |
930 | /// type, we aren't referring to any type in particular, but rather a | |
931 | /// kind of "fresh" type that is distinct from all other types we have | |
932 | /// actually declared. This is called a **placeholder** type, and we | |
933 | /// use universes to talk about this. In other words, a type name in | |
934 | /// universe 0 always corresponds to some "ground" type that the user | |
935 | /// declared, but a type name in a non-zero universe is a placeholder | |
936 | /// type -- an idealized representative of "types in general" that we | |
937 | /// use for checking generic functions. | |
0bf4aa26 | 938 | pub struct UniverseIndex { |
60c5eb7d | 939 | derive [HashStable] |
0bf4aa26 XL |
940 | DEBUG_FORMAT = "U{}", |
941 | } | |
942 | } | |
0531ce1d | 943 | |
0bf4aa26 | 944 | impl UniverseIndex { |
ba9703b0 | 945 | pub const ROOT: UniverseIndex = UniverseIndex::from_u32(0); |
8faf50e0 | 946 | |
0bf4aa26 XL |
947 | /// Returns the "next" universe index in order -- this new index |
948 | /// is considered to extend all previous universes. This | |
9fa01778 | 949 | /// corresponds to entering a `forall` quantifier. So, for |
0bf4aa26 | 950 | /// example, suppose we have this type in universe `U`: |
0531ce1d XL |
951 | /// |
952 | /// ``` | |
953 | /// for<'a> fn(&'a u32) | |
954 | /// ``` | |
955 | /// | |
956 | /// Once we "enter" into this `for<'a>` quantifier, we are in a | |
0bf4aa26 XL |
957 | /// new universe that extends `U` -- in this new universe, we can |
958 | /// name the region `'a`, but that region was not nameable from | |
959 | /// `U` because it was not in scope there. | |
960 | pub fn next_universe(self) -> UniverseIndex { | |
961 | UniverseIndex::from_u32(self.private.checked_add(1).unwrap()) | |
8faf50e0 XL |
962 | } |
963 | ||
a1dfa0c6 | 964 | /// Returns `true` if `self` can name a name from `other` -- in other words, |
0bf4aa26 | 965 | /// if the set of names in `self` is a superset of those in |
a1dfa0c6 | 966 | /// `other` (`self >= other`). |
0bf4aa26 XL |
967 | pub fn can_name(self, other: UniverseIndex) -> bool { |
968 | self.private >= other.private | |
83c7162d | 969 | } |
a1dfa0c6 XL |
970 | |
971 | /// Returns `true` if `self` cannot name some names from `other` -- in other | |
972 | /// words, if the set of names in `self` is a strict subset of | |
973 | /// those in `other` (`self < other`). | |
974 | pub fn cannot_name(self, other: UniverseIndex) -> bool { | |
975 | self.private < other.private | |
976 | } | |
83c7162d XL |
977 | } |
978 | ||
fc512014 XL |
979 | /// The "placeholder index" fully defines a placeholder region, type, or const. Placeholders are |
980 | /// identified by both a universe, as well as a name residing within that universe. Distinct bound | |
981 | /// regions/types/consts within the same universe simply have an unknown relationship to one | |
0bf4aa26 | 982 | /// another. |
3dfed10e | 983 | #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, TyEncodable, TyDecodable, PartialOrd, Ord)] |
a1dfa0c6 | 984 | pub struct Placeholder<T> { |
0bf4aa26 | 985 | pub universe: UniverseIndex, |
a1dfa0c6 | 986 | pub name: T, |
0531ce1d XL |
987 | } |
988 | ||
dc9dc135 XL |
989 | impl<'a, T> HashStable<StableHashingContext<'a>> for Placeholder<T> |
990 | where | |
991 | T: HashStable<StableHashingContext<'a>>, | |
a1dfa0c6 | 992 | { |
e74abb32 | 993 | fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) { |
a1dfa0c6 XL |
994 | self.universe.hash_stable(hcx, hasher); |
995 | self.name.hash_stable(hcx, hasher); | |
996 | } | |
997 | } | |
998 | ||
fc512014 | 999 | pub type PlaceholderRegion = Placeholder<BoundRegionKind>; |
a1dfa0c6 XL |
1000 | |
1001 | pub type PlaceholderType = Placeholder<BoundVar>; | |
1002 | ||
fc512014 XL |
1003 | #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, HashStable)] |
1004 | #[derive(TyEncodable, TyDecodable, PartialOrd, Ord)] | |
1005 | pub struct BoundConst<'tcx> { | |
1006 | pub var: BoundVar, | |
1007 | pub ty: Ty<'tcx>, | |
1008 | } | |
1009 | ||
1010 | pub type PlaceholderConst<'tcx> = Placeholder<BoundConst<'tcx>>; | |
48663c56 | 1011 | |
fc512014 XL |
1012 | /// A `DefId` which, in case it is a const argument, is potentially bundled with |
1013 | /// the `DefId` of the generic parameter it instantiates. | |
3dfed10e | 1014 | /// |
fc512014 XL |
1015 | /// This is used to avoid calls to `type_of` for const arguments during typeck |
1016 | /// which cause cycle errors. | |
3dfed10e XL |
1017 | /// |
1018 | /// ```rust | |
3dfed10e XL |
1019 | /// struct A; |
1020 | /// impl A { | |
fc512014 XL |
1021 | /// fn foo<const N: usize>(&self) -> [u8; N] { [0; N] } |
1022 | /// // ^ const parameter | |
3dfed10e XL |
1023 | /// } |
1024 | /// struct B; | |
1025 | /// impl B { | |
fc512014 XL |
1026 | /// fn foo<const M: u8>(&self) -> usize { 42 } |
1027 | /// // ^ const parameter | |
3dfed10e XL |
1028 | /// } |
1029 | /// | |
1030 | /// fn main() { | |
1031 | /// let a = A; | |
fc512014 XL |
1032 | /// let _b = a.foo::<{ 3 + 7 }>(); |
1033 | /// // ^^^^^^^^^ const argument | |
3dfed10e XL |
1034 | /// } |
1035 | /// ``` | |
fc512014 XL |
1036 | /// |
1037 | /// Let's look at the call `a.foo::<{ 3 + 7 }>()` here. We do not know | |
1038 | /// which `foo` is used until we know the type of `a`. | |
1039 | /// | |
1040 | /// We only know the type of `a` once we are inside of `typeck(main)`. | |
1041 | /// We also end up normalizing the type of `_b` during `typeck(main)` which | |
1042 | /// requires us to evaluate the const argument. | |
1043 | /// | |
1044 | /// To evaluate that const argument we need to know its type, | |
1045 | /// which we would get using `type_of(const_arg)`. This requires us to | |
1046 | /// resolve `foo` as it can be either `usize` or `u8` in this example. | |
1047 | /// However, resolving `foo` once again requires `typeck(main)` to get the type of `a`, | |
1048 | /// which results in a cycle. | |
1049 | /// | |
1050 | /// In short we must not call `type_of(const_arg)` during `typeck(main)`. | |
1051 | /// | |
1052 | /// When first creating the `ty::Const` of the const argument inside of `typeck` we have | |
1053 | /// already resolved `foo` so we know which const parameter this argument instantiates. | |
1054 | /// This means that we also know the expected result of `type_of(const_arg)` even if we | |
1055 | /// aren't allowed to call that query: it is equal to `type_of(const_param)` which is | |
1056 | /// trivial to compute. | |
1057 | /// | |
1058 | /// If we now want to use that constant in a place which potentionally needs its type | |
1059 | /// we also pass the type of its `const_param`. This is the point of `WithOptConstParam`, | |
1060 | /// except that instead of a `Ty` we bundle the `DefId` of the const parameter. | |
1061 | /// Meaning that we need to use `type_of(const_param_did)` if `const_param_did` is `Some` | |
1062 | /// to get the type of `did`. | |
3dfed10e XL |
1063 | #[derive(Copy, Clone, Debug, TypeFoldable, Lift, TyEncodable, TyDecodable)] |
1064 | #[derive(PartialEq, Eq, PartialOrd, Ord)] | |
1065 | #[derive(Hash, HashStable)] | |
1066 | pub struct WithOptConstParam<T> { | |
1067 | pub did: T, | |
29967ef6 | 1068 | /// The `DefId` of the corresponding generic parameter in case `did` is |
3dfed10e XL |
1069 | /// a const argument. |
1070 | /// | |
1071 | /// Note that even if `did` is a const argument, this may still be `None`. | |
1072 | /// All queries taking `WithOptConstParam` start by calling `tcx.opt_const_param_of(def.did)` | |
fc512014 | 1073 | /// to potentially update `param_did` in the case it is `None`. |
3dfed10e XL |
1074 | pub const_param_did: Option<DefId>, |
1075 | } | |
1076 | ||
1077 | impl<T> WithOptConstParam<T> { | |
1078 | /// Creates a new `WithOptConstParam` setting `const_param_did` to `None`. | |
1079 | #[inline(always)] | |
1080 | pub fn unknown(did: T) -> WithOptConstParam<T> { | |
1081 | WithOptConstParam { did, const_param_did: None } | |
1082 | } | |
1083 | } | |
1084 | ||
1085 | impl WithOptConstParam<LocalDefId> { | |
1086 | /// Returns `Some((did, param_did))` if `def_id` is a const argument, | |
1087 | /// `None` otherwise. | |
1088 | #[inline(always)] | |
1089 | pub fn try_lookup(did: LocalDefId, tcx: TyCtxt<'_>) -> Option<(LocalDefId, DefId)> { | |
1090 | tcx.opt_const_param_of(did).map(|param_did| (did, param_did)) | |
1091 | } | |
1092 | ||
1093 | /// In case `self` is unknown but `self.did` is a const argument, this returns | |
1094 | /// a `WithOptConstParam` with the correct `const_param_did`. | |
1095 | #[inline(always)] | |
1096 | pub fn try_upgrade(self, tcx: TyCtxt<'_>) -> Option<WithOptConstParam<LocalDefId>> { | |
1097 | if self.const_param_did.is_none() { | |
1098 | if let const_param_did @ Some(_) = tcx.opt_const_param_of(self.did) { | |
1099 | return Some(WithOptConstParam { did: self.did, const_param_did }); | |
1100 | } | |
1101 | } | |
1102 | ||
1103 | None | |
1104 | } | |
1105 | ||
1106 | pub fn to_global(self) -> WithOptConstParam<DefId> { | |
1107 | WithOptConstParam { did: self.did.to_def_id(), const_param_did: self.const_param_did } | |
1108 | } | |
1109 | ||
1110 | pub fn def_id_for_type_of(self) -> DefId { | |
1111 | if let Some(did) = self.const_param_did { did } else { self.did.to_def_id() } | |
1112 | } | |
1113 | } | |
1114 | ||
1115 | impl WithOptConstParam<DefId> { | |
1116 | pub fn as_local(self) -> Option<WithOptConstParam<LocalDefId>> { | |
1117 | self.did | |
1118 | .as_local() | |
1119 | .map(|did| WithOptConstParam { did, const_param_did: self.const_param_did }) | |
1120 | } | |
1121 | ||
1122 | pub fn as_const_arg(self) -> Option<(LocalDefId, DefId)> { | |
1123 | if let Some(param_did) = self.const_param_did { | |
1124 | if let Some(did) = self.did.as_local() { | |
1125 | return Some((did, param_did)); | |
1126 | } | |
1127 | } | |
1128 | ||
1129 | None | |
1130 | } | |
1131 | ||
3dfed10e XL |
1132 | pub fn is_local(self) -> bool { |
1133 | self.did.is_local() | |
1134 | } | |
1135 | ||
1136 | pub fn def_id_for_type_of(self) -> DefId { | |
1137 | self.const_param_did.unwrap_or(self.did) | |
1138 | } | |
1139 | } | |
1140 | ||
7cac9316 XL |
1141 | /// When type checking, we use the `ParamEnv` to track |
1142 | /// details about the set of where-clauses that are in scope at this | |
1143 | /// particular point. | |
3dfed10e | 1144 | #[derive(Copy, Clone, Hash, PartialEq, Eq)] |
7cac9316 | 1145 | pub struct ParamEnv<'tcx> { |
3dfed10e XL |
1146 | /// This packs both caller bounds and the reveal enum into one pointer. |
1147 | /// | |
1148 | /// Caller bounds are `Obligation`s that the caller must satisfy. This is | |
1149 | /// basically the set of bounds on the in-scope type parameters, translated | |
416331ca | 1150 | /// into `Obligation`s, and elaborated and normalized. |
f035d41b | 1151 | /// |
3dfed10e XL |
1152 | /// Use the `caller_bounds()` method to access. |
1153 | /// | |
94b46f34 | 1154 | /// Typically, this is `Reveal::UserFacing`, but during codegen we |
f035d41b XL |
1155 | /// want `Reveal::All`. |
1156 | /// | |
3dfed10e XL |
1157 | /// Note: This is packed, use the reveal() method to access it. |
1158 | packed: CopyTaggedPtr<&'tcx List<Predicate<'tcx>>, traits::Reveal, true>, | |
7cac9316 XL |
1159 | } |
1160 | ||
3dfed10e XL |
1161 | unsafe impl rustc_data_structures::tagged_ptr::Tag for traits::Reveal { |
1162 | const BITS: usize = 1; | |
17df50a5 | 1163 | #[inline] |
3dfed10e XL |
1164 | fn into_usize(self) -> usize { |
1165 | match self { | |
1166 | traits::Reveal::UserFacing => 0, | |
1167 | traits::Reveal::All => 1, | |
1168 | } | |
1169 | } | |
17df50a5 | 1170 | #[inline] |
3dfed10e XL |
1171 | unsafe fn from_usize(ptr: usize) -> Self { |
1172 | match ptr { | |
1173 | 0 => traits::Reveal::UserFacing, | |
1174 | 1 => traits::Reveal::All, | |
1175 | _ => std::hint::unreachable_unchecked(), | |
1176 | } | |
1177 | } | |
1178 | } | |
1179 | ||
f035d41b XL |
1180 | impl<'tcx> fmt::Debug for ParamEnv<'tcx> { |
1181 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { | |
1182 | f.debug_struct("ParamEnv") | |
1183 | .field("caller_bounds", &self.caller_bounds()) | |
1184 | .field("reveal", &self.reveal()) | |
f035d41b XL |
1185 | .finish() |
1186 | } | |
1187 | } | |
1188 | ||
f035d41b XL |
1189 | impl<'a, 'tcx> HashStable<StableHashingContext<'a>> for ParamEnv<'tcx> { |
1190 | fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) { | |
1191 | self.caller_bounds().hash_stable(hcx, hasher); | |
1192 | self.reveal().hash_stable(hcx, hasher); | |
f035d41b XL |
1193 | } |
1194 | } | |
1195 | ||
1196 | impl<'tcx> TypeFoldable<'tcx> for ParamEnv<'tcx> { | |
fc512014 | 1197 | fn super_fold_with<F: ty::fold::TypeFolder<'tcx>>(self, folder: &mut F) -> Self { |
1b1a35ee | 1198 | ParamEnv::new(self.caller_bounds().fold_with(folder), self.reveal().fold_with(folder)) |
f035d41b XL |
1199 | } |
1200 | ||
fc512014 | 1201 | fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> { |
29967ef6 XL |
1202 | self.caller_bounds().visit_with(visitor)?; |
1203 | self.reveal().visit_with(visitor) | |
f035d41b XL |
1204 | } |
1205 | } | |
1206 | ||
7cac9316 | 1207 | impl<'tcx> ParamEnv<'tcx> { |
0531ce1d | 1208 | /// Construct a trait environment suitable for contexts where |
9fa01778 | 1209 | /// there are no where-clauses in scope. Hidden types (like `impl |
0531ce1d XL |
1210 | /// Trait`) are left hidden, so this is suitable for ordinary |
1211 | /// type-checking. | |
a1dfa0c6 | 1212 | #[inline] |
0531ce1d | 1213 | pub fn empty() -> Self { |
1b1a35ee | 1214 | Self::new(List::empty(), Reveal::UserFacing) |
0531ce1d XL |
1215 | } |
1216 | ||
f035d41b | 1217 | #[inline] |
3dfed10e XL |
1218 | pub fn caller_bounds(self) -> &'tcx List<Predicate<'tcx>> { |
1219 | self.packed.pointer() | |
f035d41b XL |
1220 | } |
1221 | ||
1222 | #[inline] | |
1223 | pub fn reveal(self) -> traits::Reveal { | |
3dfed10e | 1224 | self.packed.tag() |
f035d41b XL |
1225 | } |
1226 | ||
9fa01778 | 1227 | /// Construct a trait environment with no where-clauses in scope |
0531ce1d XL |
1228 | /// where the values of all `impl Trait` and other hidden types |
1229 | /// are revealed. This is suitable for monomorphized, post-typeck | |
94b46f34 | 1230 | /// environments like codegen or doing optimizations. |
0531ce1d | 1231 | /// |
9fa01778 | 1232 | /// N.B., if you want to have predicates in scope, use `ParamEnv::new`, |
0531ce1d | 1233 | /// or invoke `param_env.with_reveal_all()`. |
a1dfa0c6 | 1234 | #[inline] |
0531ce1d | 1235 | pub fn reveal_all() -> Self { |
1b1a35ee | 1236 | Self::new(List::empty(), Reveal::All) |
0531ce1d XL |
1237 | } |
1238 | ||
1239 | /// Construct a trait environment with the given set of predicates. | |
a1dfa0c6 | 1240 | #[inline] |
1b1a35ee XL |
1241 | pub fn new(caller_bounds: &'tcx List<Predicate<'tcx>>, reveal: Reveal) -> Self { |
1242 | ty::ParamEnv { packed: CopyTaggedPtr::new(caller_bounds, reveal) } | |
f035d41b XL |
1243 | } |
1244 | ||
1245 | pub fn with_user_facing(mut self) -> Self { | |
3dfed10e | 1246 | self.packed.set_tag(Reveal::UserFacing); |
f035d41b | 1247 | self |
0531ce1d XL |
1248 | } |
1249 | ||
1250 | /// Returns a new parameter environment with the same clauses, but | |
1251 | /// which "reveals" the true results of projections in all cases | |
9fa01778 | 1252 | /// (even for associated types that are specializable). This is |
94b46f34 | 1253 | /// the desired behavior during codegen and certain other special |
0531ce1d XL |
1254 | /// contexts; normally though we want to use `Reveal::UserFacing`, |
1255 | /// which is the default. | |
3dfed10e XL |
1256 | /// All opaque types in the caller_bounds of the `ParamEnv` |
1257 | /// will be normalized to their underlying types. | |
1258 | /// See PR #65989 and issue #65918 for more details | |
1259 | pub fn with_reveal_all_normalized(self, tcx: TyCtxt<'tcx>) -> Self { | |
1260 | if self.packed.tag() == traits::Reveal::All { | |
1261 | return self; | |
1262 | } | |
1263 | ||
1b1a35ee | 1264 | ParamEnv::new(tcx.normalize_opaque_types(self.caller_bounds()), Reveal::All) |
0531ce1d XL |
1265 | } |
1266 | ||
1267 | /// Returns this same environment but with no caller bounds. | |
17df50a5 | 1268 | #[inline] |
0531ce1d | 1269 | pub fn without_caller_bounds(self) -> Self { |
1b1a35ee | 1270 | Self::new(List::empty(), self.reveal()) |
0531ce1d XL |
1271 | } |
1272 | ||
7cac9316 | 1273 | /// Creates a suitable environment in which to perform trait |
0531ce1d XL |
1274 | /// queries on the given value. When type-checking, this is simply |
1275 | /// the pair of the environment plus value. But when reveal is set to | |
1276 | /// All, then if `value` does not reference any type parameters, we will | |
1277 | /// pair it with the empty environment. This improves caching and is generally | |
1278 | /// invisible. | |
e9174d1e | 1279 | /// |
0731742a | 1280 | /// N.B., we preserve the environment when type-checking because it |
0531ce1d | 1281 | /// is possible for the user to have wacky where-clauses like |
7cac9316 | 1282 | /// `where Box<u32>: Copy`, which are clearly never |
0531ce1d XL |
1283 | /// satisfiable. We generally want to behave as if they were true, |
1284 | /// although the surrounding function is never reachable. | |
7cac9316 | 1285 | pub fn and<T: TypeFoldable<'tcx>>(self, value: T) -> ParamEnvAnd<'tcx, T> { |
f035d41b | 1286 | match self.reveal() { |
dfeec247 | 1287 | Reveal::UserFacing => ParamEnvAnd { param_env: self, value }, |
0531ce1d XL |
1288 | |
1289 | Reveal::All => { | |
94222f64 | 1290 | if value.is_known_global() { |
dfeec247 | 1291 | ParamEnvAnd { param_env: self.without_caller_bounds(), value } |
74b04a01 XL |
1292 | } else { |
1293 | ParamEnvAnd { param_env: self, value } | |
0531ce1d | 1294 | } |
e9174d1e SL |
1295 | } |
1296 | } | |
1297 | } | |
1298 | } | |
1299 | ||
fc512014 | 1300 | #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, TypeFoldable)] |
dfeec247 | 1301 | pub struct ConstnessAnd<T> { |
94222f64 | 1302 | pub constness: BoundConstness, |
dfeec247 XL |
1303 | pub value: T, |
1304 | } | |
1305 | ||
f9f354fc | 1306 | // FIXME(ecstaticmorse): Audit all occurrences of `without_const().to_predicate(tcx)` to ensure that |
dfeec247 XL |
1307 | // the constness of trait bounds is being propagated correctly. |
1308 | pub trait WithConstness: Sized { | |
1309 | #[inline] | |
94222f64 | 1310 | fn with_constness(self, constness: BoundConstness) -> ConstnessAnd<Self> { |
dfeec247 XL |
1311 | ConstnessAnd { constness, value: self } |
1312 | } | |
1313 | ||
1314 | #[inline] | |
94222f64 XL |
1315 | fn with_const_if_const(self) -> ConstnessAnd<Self> { |
1316 | self.with_constness(BoundConstness::ConstIfConst) | |
dfeec247 XL |
1317 | } |
1318 | ||
1319 | #[inline] | |
1320 | fn without_const(self) -> ConstnessAnd<Self> { | |
94222f64 | 1321 | self.with_constness(BoundConstness::NotConst) |
dfeec247 XL |
1322 | } |
1323 | } | |
1324 | ||
1325 | impl<T> WithConstness for T {} | |
1326 | ||
60c5eb7d | 1327 | #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, TypeFoldable)] |
7cac9316 XL |
1328 | pub struct ParamEnvAnd<'tcx, T> { |
1329 | pub param_env: ParamEnv<'tcx>, | |
1330 | pub value: T, | |
1331 | } | |
1332 | ||
1333 | impl<'tcx, T> ParamEnvAnd<'tcx, T> { | |
1334 | pub fn into_parts(self) -> (ParamEnv<'tcx>, T) { | |
1335 | (self.param_env, self.value) | |
1336 | } | |
1337 | } | |
1338 | ||
dc9dc135 XL |
1339 | impl<'a, 'tcx, T> HashStable<StableHashingContext<'a>> for ParamEnvAnd<'tcx, T> |
1340 | where | |
1341 | T: HashStable<StableHashingContext<'a>>, | |
ea8adc8c | 1342 | { |
e74abb32 | 1343 | fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) { |
dfeec247 | 1344 | let ParamEnvAnd { ref param_env, ref value } = *self; |
ea8adc8c XL |
1345 | |
1346 | param_env.hash_stable(hcx, hasher); | |
1347 | value.hash_stable(hcx, hasher); | |
1348 | } | |
1349 | } | |
1350 | ||
532ac7d7 | 1351 | #[derive(Copy, Clone, Debug, HashStable)] |
8bb4bdeb | 1352 | pub struct Destructor { |
9fa01778 | 1353 | /// The `DefId` of the destructor method |
8bb4bdeb | 1354 | pub did: DefId, |
c295e0f8 XL |
1355 | /// The constness of the destructor method |
1356 | pub constness: hir::Constness, | |
8bb4bdeb XL |
1357 | } |
1358 | ||
b7449926 | 1359 | bitflags! { |
532ac7d7 | 1360 | #[derive(HashStable)] |
b7449926 XL |
1361 | pub struct VariantFlags: u32 { |
1362 | const NO_VARIANT_FLAGS = 0; | |
1363 | /// Indicates whether the field list of this variant is `#[non_exhaustive]`. | |
1364 | const IS_FIELD_LIST_NON_EXHAUSTIVE = 1 << 0; | |
1b1a35ee XL |
1365 | /// Indicates whether this variant was obtained as part of recovering from |
1366 | /// a syntactic error. May be incomplete or bogus. | |
1367 | const IS_RECOVERED = 1 << 1; | |
e9174d1e SL |
1368 | } |
1369 | } | |
1370 | ||
94222f64 | 1371 | /// Definition of a variant -- a struct's fields or an enum variant. |
60c5eb7d | 1372 | #[derive(Debug, HashStable)] |
476ff2be | 1373 | pub struct VariantDef { |
532ac7d7 XL |
1374 | /// `DefId` that identifies the variant itself. |
1375 | /// If this variant belongs to a struct or union, then this is a copy of its `DefId`. | |
1376 | pub def_id: DefId, | |
1377 | /// `DefId` that identifies the variant's constructor. | |
1378 | /// If this variant is a struct variant, then this is `None`. | |
1379 | pub ctor_def_id: Option<DefId>, | |
1380 | /// Variant or struct name. | |
60c5eb7d | 1381 | #[stable_hasher(project(name))] |
532ac7d7 XL |
1382 | pub ident: Ident, |
1383 | /// Discriminant of this variant. | |
8bb4bdeb | 1384 | pub discr: VariantDiscr, |
532ac7d7 | 1385 | /// Fields of this variant. |
476ff2be | 1386 | pub fields: Vec<FieldDef>, |
532ac7d7 | 1387 | /// Type of constructor of variant. |
c30ab7b3 | 1388 | pub ctor_kind: CtorKind, |
532ac7d7 | 1389 | /// Flags of the variant (e.g. is field list non-exhaustive)? |
b7449926 | 1390 | flags: VariantFlags, |
e9174d1e SL |
1391 | } |
1392 | ||
1b1a35ee | 1393 | impl VariantDef { |
9fa01778 | 1394 | /// Creates a new `VariantDef`. |
b7449926 | 1395 | /// |
532ac7d7 XL |
1396 | /// `variant_did` is the `DefId` that identifies the enum variant (if this `VariantDef` |
1397 | /// represents an enum variant). | |
1398 | /// | |
1399 | /// `ctor_did` is the `DefId` that identifies the constructor of unit or | |
1400 | /// tuple-variants/structs. If this is a `struct`-variant then this should be `None`. | |
0bf4aa26 | 1401 | /// |
532ac7d7 XL |
1402 | /// `parent_did` is the `DefId` of the `AdtDef` representing the enum or struct that |
1403 | /// owns this variant. It is used for checking if a struct has `#[non_exhaustive]` w/out having | |
1404 | /// to go through the redirect of checking the ctor's attributes - but compiling a small crate | |
1405 | /// requires loading the `AdtDef`s for all the structs in the universe (e.g., coherence for any | |
0bf4aa26 XL |
1406 | /// built-in trait), and we do not want to load attributes twice. |
1407 | /// | |
1408 | /// If someone speeds up attribute loading to not be a performance concern, they can | |
9fa01778 | 1409 | /// remove this hack and use the constructor `DefId` everywhere. |
532ac7d7 | 1410 | pub fn new( |
532ac7d7 XL |
1411 | ident: Ident, |
1412 | variant_did: Option<DefId>, | |
1413 | ctor_def_id: Option<DefId>, | |
1414 | discr: VariantDiscr, | |
1415 | fields: Vec<FieldDef>, | |
1416 | ctor_kind: CtorKind, | |
1417 | adt_kind: AdtKind, | |
1418 | parent_did: DefId, | |
1419 | recovered: bool, | |
3dfed10e | 1420 | is_field_list_non_exhaustive: bool, |
532ac7d7 XL |
1421 | ) -> Self { |
1422 | debug!( | |
1423 | "VariantDef::new(ident = {:?}, variant_did = {:?}, ctor_def_id = {:?}, discr = {:?}, | |
1424 | fields = {:?}, ctor_kind = {:?}, adt_kind = {:?}, parent_did = {:?})", | |
dfeec247 | 1425 | ident, variant_did, ctor_def_id, discr, fields, ctor_kind, adt_kind, parent_did, |
532ac7d7 XL |
1426 | ); |
1427 | ||
b7449926 | 1428 | let mut flags = VariantFlags::NO_VARIANT_FLAGS; |
3dfed10e XL |
1429 | if is_field_list_non_exhaustive { |
1430 | flags |= VariantFlags::IS_FIELD_LIST_NON_EXHAUSTIVE; | |
b7449926 | 1431 | } |
532ac7d7 | 1432 | |
1b1a35ee XL |
1433 | if recovered { |
1434 | flags |= VariantFlags::IS_RECOVERED; | |
1435 | } | |
1436 | ||
b7449926 | 1437 | VariantDef { |
532ac7d7 XL |
1438 | def_id: variant_did.unwrap_or(parent_did), |
1439 | ctor_def_id, | |
0731742a | 1440 | ident, |
b7449926 XL |
1441 | discr, |
1442 | fields, | |
1443 | ctor_kind, | |
532ac7d7 | 1444 | flags, |
b7449926 XL |
1445 | } |
1446 | } | |
1447 | ||
532ac7d7 | 1448 | /// Is this field list non-exhaustive? |
b7449926 XL |
1449 | #[inline] |
1450 | pub fn is_field_list_non_exhaustive(&self) -> bool { | |
1451 | self.flags.intersects(VariantFlags::IS_FIELD_LIST_NON_EXHAUSTIVE) | |
1452 | } | |
f035d41b | 1453 | |
1b1a35ee XL |
1454 | /// Was this variant obtained as part of recovering from a syntactic error? |
1455 | #[inline] | |
1456 | pub fn is_recovered(&self) -> bool { | |
1457 | self.flags.intersects(VariantFlags::IS_RECOVERED) | |
f035d41b | 1458 | } |
b7449926 XL |
1459 | } |
1460 | ||
3dfed10e | 1461 | #[derive(Copy, Clone, Debug, PartialEq, Eq, TyEncodable, TyDecodable, HashStable)] |
8bb4bdeb | 1462 | pub enum VariantDiscr { |
0731742a | 1463 | /// Explicit value for this variant, i.e., `X = 123`. |
8bb4bdeb XL |
1464 | /// The `DefId` corresponds to the embedded constant. |
1465 | Explicit(DefId), | |
1466 | ||
1467 | /// The previous variant's discriminant plus one. | |
1468 | /// For efficiency reasons, the distance from the | |
1469 | /// last `Explicit` discriminant is being stored, | |
1470 | /// or `0` for the first variant, if it has none. | |
a1dfa0c6 | 1471 | Relative(u32), |
8bb4bdeb XL |
1472 | } |
1473 | ||
532ac7d7 | 1474 | #[derive(Debug, HashStable)] |
476ff2be | 1475 | pub struct FieldDef { |
e9174d1e | 1476 | pub did: DefId, |
532ac7d7 | 1477 | #[stable_hasher(project(name))] |
94b46f34 | 1478 | pub ident: Ident, |
54a0048b | 1479 | pub vis: Visibility, |
e9174d1e SL |
1480 | } |
1481 | ||
cc61c64b | 1482 | bitflags! { |
3dfed10e | 1483 | #[derive(TyEncodable, TyDecodable, Default, HashStable)] |
ea8adc8c XL |
1484 | pub struct ReprFlags: u8 { |
1485 | const IS_C = 1 << 0; | |
83c7162d XL |
1486 | const IS_SIMD = 1 << 1; |
1487 | const IS_TRANSPARENT = 1 << 2; | |
cc61c64b | 1488 | // Internal only for now. If true, don't reorder fields. |
83c7162d | 1489 | const IS_LINEAR = 1 << 3; |
74b04a01 XL |
1490 | // If true, don't expose any niche to type's context. |
1491 | const HIDE_NICHE = 1 << 4; | |
c295e0f8 XL |
1492 | // If true, the type's layout can be randomized using |
1493 | // the seed stored in `ReprOptions.layout_seed` | |
1494 | const RANDOMIZE_LAYOUT = 1 << 5; | |
cc61c64b XL |
1495 | // Any of these flags being set prevent field reordering optimisation. |
1496 | const IS_UNOPTIMISABLE = ReprFlags::IS_C.bits | | |
cc61c64b | 1497 | ReprFlags::IS_SIMD.bits | |
ea8adc8c | 1498 | ReprFlags::IS_LINEAR.bits; |
cc61c64b XL |
1499 | } |
1500 | } | |
1501 | ||
8bb4bdeb | 1502 | /// Represents the repr options provided by the user, |
3dfed10e | 1503 | #[derive(Copy, Clone, Debug, Eq, PartialEq, TyEncodable, TyDecodable, Default, HashStable)] |
8bb4bdeb | 1504 | pub struct ReprOptions { |
8bb4bdeb | 1505 | pub int: Option<attr::IntType>, |
e1599b0c XL |
1506 | pub align: Option<Align>, |
1507 | pub pack: Option<Align>, | |
cc61c64b | 1508 | pub flags: ReprFlags, |
c295e0f8 XL |
1509 | /// The seed to be used for randomizing a type's layout |
1510 | /// | |
1511 | /// Note: This could technically be a `[u8; 16]` (a `u128`) which would | |
1512 | /// be the "most accurate" hash as it'd encompass the item and crate | |
1513 | /// hash without loss, but it does pay the price of being larger. | |
1514 | /// Everything's a tradeoff, a `u64` seed should be sufficient for our | |
1515 | /// purposes (primarily `-Z randomize-layout`) | |
1516 | pub field_shuffle_seed: u64, | |
8bb4bdeb XL |
1517 | } |
1518 | ||
1519 | impl ReprOptions { | |
dc9dc135 | 1520 | pub fn new(tcx: TyCtxt<'_>, did: DefId) -> ReprOptions { |
cc61c64b XL |
1521 | let mut flags = ReprFlags::empty(); |
1522 | let mut size = None; | |
e1599b0c XL |
1523 | let mut max_align: Option<Align> = None; |
1524 | let mut min_pack: Option<Align> = None; | |
c295e0f8 XL |
1525 | |
1526 | // Generate a deterministically-derived seed from the item's path hash | |
1527 | // to allow for cross-crate compilation to actually work | |
1528 | let field_shuffle_seed = tcx.def_path_hash(did).0.to_smaller_hash(); | |
1529 | ||
8bb4bdeb | 1530 | for attr in tcx.get_attrs(did).iter() { |
3dfed10e | 1531 | for r in attr::find_repr_attrs(&tcx.sess, attr) { |
cc61c64b | 1532 | flags.insert(match r { |
2c00a5a8 | 1533 | attr::ReprC => ReprFlags::IS_C, |
83c7162d | 1534 | attr::ReprPacked(pack) => { |
e1599b0c XL |
1535 | let pack = Align::from_bytes(pack as u64).unwrap(); |
1536 | min_pack = Some(if let Some(min_pack) = min_pack { | |
1537 | min_pack.min(pack) | |
83c7162d XL |
1538 | } else { |
1539 | pack | |
e1599b0c | 1540 | }); |
83c7162d | 1541 | ReprFlags::empty() |
dfeec247 | 1542 | } |
2c00a5a8 | 1543 | attr::ReprTransparent => ReprFlags::IS_TRANSPARENT, |
74b04a01 | 1544 | attr::ReprNoNiche => ReprFlags::HIDE_NICHE, |
cc61c64b XL |
1545 | attr::ReprSimd => ReprFlags::IS_SIMD, |
1546 | attr::ReprInt(i) => { | |
1547 | size = Some(i); | |
1548 | ReprFlags::empty() | |
dfeec247 | 1549 | } |
cc61c64b | 1550 | attr::ReprAlign(align) => { |
e1599b0c | 1551 | max_align = max_align.max(Some(Align::from_bytes(align as u64).unwrap())); |
cc61c64b | 1552 | ReprFlags::empty() |
dfeec247 | 1553 | } |
cc61c64b | 1554 | }); |
8bb4bdeb XL |
1555 | } |
1556 | } | |
1557 | ||
c295e0f8 XL |
1558 | // If `-Z randomize-layout` was enabled for the type definition then we can |
1559 | // consider performing layout randomization | |
1560 | if tcx.sess.opts.debugging_opts.randomize_layout { | |
1561 | flags.insert(ReprFlags::RANDOMIZE_LAYOUT); | |
1562 | } | |
1563 | ||
cc61c64b | 1564 | // This is here instead of layout because the choice must make it into metadata. |
532ac7d7 | 1565 | if !tcx.consider_optimizing(|| format!("Reorder fields of {:?}", tcx.def_path_str(did))) { |
cc61c64b XL |
1566 | flags.insert(ReprFlags::IS_LINEAR); |
1567 | } | |
c295e0f8 XL |
1568 | |
1569 | Self { int: size, align: max_align, pack: min_pack, flags, field_shuffle_seed } | |
8bb4bdeb XL |
1570 | } |
1571 | ||
cc61c64b | 1572 | #[inline] |
dfeec247 XL |
1573 | pub fn simd(&self) -> bool { |
1574 | self.flags.contains(ReprFlags::IS_SIMD) | |
1575 | } | |
c295e0f8 | 1576 | |
cc61c64b | 1577 | #[inline] |
dfeec247 XL |
1578 | pub fn c(&self) -> bool { |
1579 | self.flags.contains(ReprFlags::IS_C) | |
1580 | } | |
c295e0f8 | 1581 | |
cc61c64b | 1582 | #[inline] |
dfeec247 XL |
1583 | pub fn packed(&self) -> bool { |
1584 | self.pack.is_some() | |
1585 | } | |
c295e0f8 | 1586 | |
cc61c64b | 1587 | #[inline] |
dfeec247 XL |
1588 | pub fn transparent(&self) -> bool { |
1589 | self.flags.contains(ReprFlags::IS_TRANSPARENT) | |
1590 | } | |
c295e0f8 | 1591 | |
2c00a5a8 | 1592 | #[inline] |
dfeec247 XL |
1593 | pub fn linear(&self) -> bool { |
1594 | self.flags.contains(ReprFlags::IS_LINEAR) | |
1595 | } | |
c295e0f8 | 1596 | |
74b04a01 XL |
1597 | #[inline] |
1598 | pub fn hide_niche(&self) -> bool { | |
1599 | self.flags.contains(ReprFlags::HIDE_NICHE) | |
1600 | } | |
cc61c64b | 1601 | |
f9f354fc XL |
1602 | /// Returns the discriminant type, given these `repr` options. |
1603 | /// This must only be called on enums! | |
8bb4bdeb | 1604 | pub fn discr_type(&self) -> attr::IntType { |
2c00a5a8 | 1605 | self.int.unwrap_or(attr::SignedInt(ast::IntTy::Isize)) |
8bb4bdeb XL |
1606 | } |
1607 | ||
a1dfa0c6 | 1608 | /// Returns `true` if this `#[repr()]` should inhabit "smart enum |
8bb4bdeb XL |
1609 | /// layout" optimizations, such as representing `Foo<&T>` as a |
1610 | /// single pointer. | |
1611 | pub fn inhibit_enum_layout_opt(&self) -> bool { | |
cc61c64b | 1612 | self.c() || self.int.is_some() |
8bb4bdeb | 1613 | } |
83c7162d | 1614 | |
a1dfa0c6 | 1615 | /// Returns `true` if this `#[repr()]` should inhibit struct field reordering |
9fa01778 | 1616 | /// optimizations, such as with `repr(C)`, `repr(packed(1))`, or `repr(<int>)`. |
83c7162d | 1617 | pub fn inhibit_struct_field_reordering_opt(&self) -> bool { |
e1599b0c XL |
1618 | if let Some(pack) = self.pack { |
1619 | if pack.bytes() == 1 { | |
1620 | return true; | |
1621 | } | |
1622 | } | |
c295e0f8 | 1623 | |
e1599b0c | 1624 | self.flags.intersects(ReprFlags::IS_UNOPTIMISABLE) || self.int.is_some() |
83c7162d | 1625 | } |
a1dfa0c6 | 1626 | |
c295e0f8 XL |
1627 | /// Returns `true` if this type is valid for reordering and `-Z randomize-layout` |
1628 | /// was enabled for its declaration crate | |
1629 | pub fn can_randomize_type_layout(&self) -> bool { | |
1630 | !self.inhibit_struct_field_reordering_opt() | |
1631 | && self.flags.contains(ReprFlags::RANDOMIZE_LAYOUT) | |
1632 | } | |
1633 | ||
9fa01778 | 1634 | /// Returns `true` if this `#[repr()]` should inhibit union ABI optimisations. |
a1dfa0c6 XL |
1635 | pub fn inhibit_union_abi_opt(&self) -> bool { |
1636 | self.c() | |
1637 | } | |
8bb4bdeb XL |
1638 | } |
1639 | ||
dc9dc135 | 1640 | impl<'tcx> FieldDef { |
c295e0f8 XL |
1641 | /// Returns the type of this field. The resulting type is not normalized. The `subst` is |
1642 | /// typically obtained via the second field of `TyKind::AdtDef`. | |
dc9dc135 | 1643 | pub fn ty(&self, tcx: TyCtxt<'tcx>, subst: SubstsRef<'tcx>) -> Ty<'tcx> { |
7cac9316 | 1644 | tcx.type_of(self.did).subst(tcx, subst) |
e9174d1e | 1645 | } |
e9174d1e SL |
1646 | } |
1647 | ||
ba9703b0 | 1648 | pub type Attributes<'tcx> = &'tcx [ast::Attribute]; |
cc61c64b | 1649 | |
0731742a XL |
1650 | #[derive(Debug, PartialEq, Eq)] |
1651 | pub enum ImplOverlapKind { | |
1652 | /// These impls are always allowed to overlap. | |
dfeec247 | 1653 | Permitted { |
74b04a01 | 1654 | /// Whether or not the impl is permitted due to the trait being a `#[marker]` trait |
dfeec247 XL |
1655 | marker: bool, |
1656 | }, | |
0731742a XL |
1657 | /// These impls are allowed to overlap, but that raises |
1658 | /// an issue #33140 future-compatibility warning. | |
1659 | /// | |
1660 | /// Some background: in Rust 1.0, the trait-object types `Send + Sync` (today's | |
1661 | /// `dyn Send + Sync`) and `Sync + Send` (now `dyn Sync + Send`) were different. | |
1662 | /// | |
1663 | /// The widely-used version 0.1.0 of the crate `traitobject` had accidentally relied | |
1664 | /// that difference, making what reduces to the following set of impls: | |
1665 | /// | |
1666 | /// ``` | |
1667 | /// trait Trait {} | |
1668 | /// impl Trait for dyn Send + Sync {} | |
1669 | /// impl Trait for dyn Sync + Send {} | |
1670 | /// ``` | |
1671 | /// | |
1672 | /// Obviously, once we made these types be identical, that code causes a coherence | |
1673 | /// error and a fairly big headache for us. However, luckily for us, the trait | |
1674 | /// `Trait` used in this case is basically a marker trait, and therefore having | |
1675 | /// overlapping impls for it is sound. | |
1676 | /// | |
1677 | /// To handle this, we basically regard the trait as a marker trait, with an additional | |
1678 | /// future-compatibility warning. To avoid accidentally "stabilizing" this feature, | |
1679 | /// it has the following restrictions: | |
1680 | /// | |
1681 | /// 1. The trait must indeed be a marker-like trait (i.e., no items), and must be | |
1682 | /// positive impls. | |
1683 | /// 2. The trait-ref of both impls must be equal. | |
1684 | /// 3. The trait-ref of both impls must be a trait object type consisting only of | |
1685 | /// marker traits. | |
1686 | /// 4. Neither of the impls can have any where-clauses. | |
1687 | /// | |
1688 | /// Once `traitobject` 0.1.0 is no longer an active concern, this hack can be removed. | |
dfeec247 | 1689 | Issue33140, |
0731742a XL |
1690 | } |
1691 | ||
dc9dc135 | 1692 | impl<'tcx> TyCtxt<'tcx> { |
3dfed10e XL |
1693 | pub fn typeck_body(self, body: hir::BodyId) -> &'tcx TypeckResults<'tcx> { |
1694 | self.typeck(self.hir().body_owner_def_id(body)) | |
32a655c1 SL |
1695 | } |
1696 | ||
74b04a01 | 1697 | pub fn provided_trait_methods(self, id: DefId) -> impl 'tcx + Iterator<Item = &'tcx AssocItem> { |
476ff2be | 1698 | self.associated_items(id) |
74b04a01 | 1699 | .in_definition_order() |
ba9703b0 | 1700 | .filter(|item| item.kind == AssocKind::Fn && item.defaultness.has_value()) |
e9174d1e SL |
1701 | } |
1702 | ||
29967ef6 XL |
1703 | fn item_name_from_hir(self, def_id: DefId) -> Option<Ident> { |
1704 | self.hir().get_if_local(def_id).and_then(|node| node.ident()) | |
1705 | } | |
1706 | ||
1707 | fn item_name_from_def_id(self, def_id: DefId) -> Option<Symbol> { | |
1708 | if def_id.index == CRATE_DEF_INDEX { | |
17df50a5 | 1709 | Some(self.crate_name(def_id.krate)) |
29967ef6 XL |
1710 | } else { |
1711 | let def_key = self.def_key(def_id); | |
1712 | match def_key.disambiguated_data.data { | |
1713 | // The name of a constructor is that of its parent. | |
1714 | rustc_hir::definitions::DefPathData::Ctor => self.item_name_from_def_id(DefId { | |
1715 | krate: def_id.krate, | |
1716 | index: def_key.parent.unwrap(), | |
1717 | }), | |
1718 | _ => def_key.disambiguated_data.data.get_opt_name(), | |
1719 | } | |
1720 | } | |
1721 | } | |
1722 | ||
1723 | /// Look up the name of an item across crates. This does not look at HIR. | |
1724 | /// | |
1725 | /// When possible, this function should be used for cross-crate lookups over | |
1726 | /// [`opt_item_name`] to avoid invalidating the incremental cache. If you | |
1727 | /// need to handle items without a name, or HIR items that will not be | |
1728 | /// serialized cross-crate, or if you need the span of the item, use | |
1729 | /// [`opt_item_name`] instead. | |
1730 | /// | |
1731 | /// [`opt_item_name`]: Self::opt_item_name | |
1732 | pub fn item_name(self, id: DefId) -> Symbol { | |
1733 | // Look at cross-crate items first to avoid invalidating the incremental cache | |
1734 | // unless we have to. | |
1735 | self.item_name_from_def_id(id).unwrap_or_else(|| { | |
1736 | bug!("item_name: no name for {:?}", self.def_path(id)); | |
1737 | }) | |
1738 | } | |
1739 | ||
1740 | /// Look up the name and span of an item or [`Node`]. | |
1741 | /// | |
1742 | /// See [`item_name`][Self::item_name] for more information. | |
e1599b0c | 1743 | pub fn opt_item_name(self, def_id: DefId) -> Option<Ident> { |
29967ef6 XL |
1744 | // Look at the HIR first so the span will be correct if this is a local item. |
1745 | self.item_name_from_hir(def_id) | |
1746 | .or_else(|| self.item_name_from_def_id(def_id).map(Ident::with_dummy_span)) | |
e1599b0c XL |
1747 | } |
1748 | ||
f9f354fc | 1749 | pub fn opt_associated_item(self, def_id: DefId) -> Option<&'tcx AssocItem> { |
5869c6ff XL |
1750 | if let DefKind::AssocConst | DefKind::AssocFn | DefKind::AssocTy = self.def_kind(def_id) { |
1751 | Some(self.associated_item(def_id)) | |
7cac9316 | 1752 | } else { |
5869c6ff XL |
1753 | None |
1754 | } | |
e9174d1e SL |
1755 | } |
1756 | ||
3dfed10e XL |
1757 | pub fn field_index(self, hir_id: hir::HirId, typeck_results: &TypeckResults<'_>) -> usize { |
1758 | typeck_results.field_indices().get(hir_id).cloned().expect("no index for a field") | |
83c7162d XL |
1759 | } |
1760 | ||
1761 | pub fn find_field_index(self, ident: Ident, variant: &VariantDef) -> Option<usize> { | |
dfeec247 | 1762 | variant.fields.iter().position(|field| self.hygienic_eq(ident, field.ident, variant.def_id)) |
83c7162d XL |
1763 | } |
1764 | ||
a1dfa0c6 | 1765 | /// Returns `true` if the impls are the same polarity and the trait either |
f9f354fc | 1766 | /// has no items or is annotated `#[marker]` and prevents item overrides. |
dfeec247 XL |
1767 | pub fn impls_are_allowed_to_overlap( |
1768 | self, | |
1769 | def_id1: DefId, | |
1770 | def_id2: DefId, | |
1771 | ) -> Option<ImplOverlapKind> { | |
e1599b0c XL |
1772 | // If either trait impl references an error, they're allowed to overlap, |
1773 | // as one of them essentially doesn't exist. | |
dfeec247 XL |
1774 | if self.impl_trait_ref(def_id1).map_or(false, |tr| tr.references_error()) |
1775 | || self.impl_trait_ref(def_id2).map_or(false, |tr| tr.references_error()) | |
1776 | { | |
1777 | return Some(ImplOverlapKind::Permitted { marker: false }); | |
e1599b0c XL |
1778 | } |
1779 | ||
e74abb32 | 1780 | match (self.impl_polarity(def_id1), self.impl_polarity(def_id2)) { |
dfeec247 | 1781 | (ImplPolarity::Reservation, _) | (_, ImplPolarity::Reservation) => { |
e74abb32 | 1782 | // `#[rustc_reservation_impl]` impls don't overlap with anything |
dfeec247 XL |
1783 | debug!( |
1784 | "impls_are_allowed_to_overlap({:?}, {:?}) = Some(Permitted) (reservations)", | |
1785 | def_id1, def_id2 | |
1786 | ); | |
1787 | return Some(ImplOverlapKind::Permitted { marker: false }); | |
e74abb32 | 1788 | } |
dfeec247 XL |
1789 | (ImplPolarity::Positive, ImplPolarity::Negative) |
1790 | | (ImplPolarity::Negative, ImplPolarity::Positive) => { | |
e74abb32 | 1791 | // `impl AutoTrait for Type` + `impl !AutoTrait for Type` |
dfeec247 XL |
1792 | debug!( |
1793 | "impls_are_allowed_to_overlap({:?}, {:?}) - None (differing polarities)", | |
1794 | def_id1, def_id2 | |
1795 | ); | |
e74abb32 XL |
1796 | return None; |
1797 | } | |
dfeec247 XL |
1798 | (ImplPolarity::Positive, ImplPolarity::Positive) |
1799 | | (ImplPolarity::Negative, ImplPolarity::Negative) => {} | |
e74abb32 XL |
1800 | }; |
1801 | ||
74b04a01 | 1802 | let is_marker_overlap = { |
0bf4aa26 XL |
1803 | let is_marker_impl = |def_id: DefId| -> bool { |
1804 | let trait_ref = self.impl_trait_ref(def_id); | |
1805 | trait_ref.map_or(false, |tr| self.trait_def(tr.def_id).is_marker) | |
1806 | }; | |
e74abb32 | 1807 | is_marker_impl(def_id1) && is_marker_impl(def_id2) |
0731742a XL |
1808 | }; |
1809 | ||
e74abb32 | 1810 | if is_marker_overlap { |
dfeec247 XL |
1811 | debug!( |
1812 | "impls_are_allowed_to_overlap({:?}, {:?}) = Some(Permitted) (marker overlap)", | |
1813 | def_id1, def_id2 | |
1814 | ); | |
1815 | Some(ImplOverlapKind::Permitted { marker: true }) | |
0bf4aa26 | 1816 | } else { |
0731742a XL |
1817 | if let Some(self_ty1) = self.issue33140_self_ty(def_id1) { |
1818 | if let Some(self_ty2) = self.issue33140_self_ty(def_id2) { | |
1819 | if self_ty1 == self_ty2 { | |
dfeec247 XL |
1820 | debug!( |
1821 | "impls_are_allowed_to_overlap({:?}, {:?}) - issue #33140 HACK", | |
1822 | def_id1, def_id2 | |
1823 | ); | |
0731742a XL |
1824 | return Some(ImplOverlapKind::Issue33140); |
1825 | } else { | |
dfeec247 XL |
1826 | debug!( |
1827 | "impls_are_allowed_to_overlap({:?}, {:?}) - found {:?} != {:?}", | |
1828 | def_id1, def_id2, self_ty1, self_ty2 | |
1829 | ); | |
0731742a XL |
1830 | } |
1831 | } | |
1832 | } | |
1833 | ||
dfeec247 | 1834 | debug!("impls_are_allowed_to_overlap({:?}, {:?}) = None", def_id1, def_id2); |
0731742a | 1835 | None |
cc61c64b | 1836 | } |
cc61c64b XL |
1837 | } |
1838 | ||
48663c56 | 1839 | /// Returns `ty::VariantDef` if `res` refers to a struct, |
532ac7d7 | 1840 | /// or variant or their constructors, panics otherwise. |
48663c56 XL |
1841 | pub fn expect_variant_res(self, res: Res) -> &'tcx VariantDef { |
1842 | match res { | |
1843 | Res::Def(DefKind::Variant, did) => { | |
532ac7d7 | 1844 | let enum_did = self.parent(did).unwrap(); |
7cac9316 | 1845 | self.adt_def(enum_did).variant_with_id(did) |
5bcae85e | 1846 | } |
ba9703b0 | 1847 | Res::Def(DefKind::Struct | DefKind::Union, did) => self.adt_def(did).non_enum_variant(), |
48663c56 | 1848 | Res::Def(DefKind::Ctor(CtorOf::Variant, ..), variant_ctor_did) => { |
532ac7d7 XL |
1849 | let variant_did = self.parent(variant_ctor_did).unwrap(); |
1850 | let enum_did = self.parent(variant_did).unwrap(); | |
1851 | self.adt_def(enum_did).variant_with_ctor_id(variant_ctor_did) | |
1852 | } | |
48663c56 | 1853 | Res::Def(DefKind::Ctor(CtorOf::Struct, ..), ctor_did) => { |
532ac7d7 XL |
1854 | let struct_did = self.parent(ctor_did).expect("struct ctor has no parent"); |
1855 | self.adt_def(struct_did).non_enum_variant() | |
c30ab7b3 | 1856 | } |
dfeec247 | 1857 | _ => bug!("expect_variant_res used with unexpected res {:?}", res), |
5bcae85e SL |
1858 | } |
1859 | } | |
1860 | ||
9fa01778 | 1861 | /// Returns the possibly-auto-generated MIR of a `(DefId, Subst)` pair. |
f9f354fc | 1862 | pub fn instance_mir(self, instance: ty::InstanceDef<'tcx>) -> &'tcx Body<'tcx> { |
cc61c64b | 1863 | match instance { |
5869c6ff XL |
1864 | ty::InstanceDef::Item(def) => match self.def_kind(def.did) { |
1865 | DefKind::Const | |
1866 | | DefKind::Static | |
1867 | | DefKind::AssocConst | |
1868 | | DefKind::Ctor(..) | |
1869 | | DefKind::AnonConst => self.mir_for_ctfe_opt_const_arg(def), | |
1870 | // If the caller wants `mir_for_ctfe` of a function they should not be using | |
1871 | // `instance_mir`, so we'll assume const fn also wants the optimized version. | |
6a06907d XL |
1872 | _ => { |
1873 | assert_eq!(def.const_param_did, None); | |
1874 | self.optimized_mir(def.did) | |
1875 | } | |
5869c6ff | 1876 | }, |
dfeec247 XL |
1877 | ty::InstanceDef::VtableShim(..) |
1878 | | ty::InstanceDef::ReifyShim(..) | |
1879 | | ty::InstanceDef::Intrinsic(..) | |
1880 | | ty::InstanceDef::FnPtrShim(..) | |
1881 | | ty::InstanceDef::Virtual(..) | |
1882 | | ty::InstanceDef::ClosureOnceShim { .. } | |
1883 | | ty::InstanceDef::DropGlue(..) | |
f9f354fc | 1884 | | ty::InstanceDef::CloneShim(..) => self.mir_shims(instance), |
cc61c64b XL |
1885 | } |
1886 | } | |
1887 | ||
9fa01778 | 1888 | /// Gets the attributes of a definition. |
dc9dc135 | 1889 | pub fn get_attrs(self, did: DefId) -> Attributes<'tcx> { |
f9f354fc | 1890 | if let Some(did) = did.as_local() { |
3dfed10e | 1891 | self.hir().attrs(self.hir().local_def_id_to_hir_id(did)) |
e9174d1e | 1892 | } else { |
ba9703b0 | 1893 | self.item_attrs(did) |
e9174d1e SL |
1894 | } |
1895 | } | |
1896 | ||
9fa01778 | 1897 | /// Determines whether an item is annotated with an attribute. |
48663c56 | 1898 | pub fn has_attr(self, did: DefId, attr: Symbol) -> bool { |
3dfed10e | 1899 | self.sess.contains_name(&self.get_attrs(did), attr) |
e9174d1e SL |
1900 | } |
1901 | ||
c295e0f8 XL |
1902 | /// Determines whether an item is annotated with `doc(hidden)`. |
1903 | pub fn is_doc_hidden(self, did: DefId) -> bool { | |
1904 | self.get_attrs(did) | |
1905 | .iter() | |
1906 | .filter_map(|attr| if attr.has_name(sym::doc) { attr.meta_item_list() } else { None }) | |
1907 | .any(|items| items.iter().any(|item| item.has_name(sym::hidden))) | |
1908 | } | |
1909 | ||
a1dfa0c6 | 1910 | /// Returns `true` if this is an `auto trait`. |
abe05a73 XL |
1911 | pub fn trait_is_auto(self, trait_def_id: DefId) -> bool { |
1912 | self.trait_def(trait_def_id).has_auto_impl | |
b039eaaf SL |
1913 | } |
1914 | ||
5869c6ff XL |
1915 | /// Returns layout of a generator. Layout might be unavailable if the |
1916 | /// generator is tainted by errors. | |
1917 | pub fn generator_layout(self, def_id: DefId) -> Option<&'tcx GeneratorLayout<'tcx>> { | |
6a06907d | 1918 | self.optimized_mir(def_id).generator_layout() |
ea8adc8c XL |
1919 | } |
1920 | ||
9fa01778 XL |
1921 | /// Given the `DefId` of an impl, returns the `DefId` of the trait it implements. |
1922 | /// If it implements no trait, returns `None`. | |
a7813a04 | 1923 | pub fn trait_id_of_impl(self, def_id: DefId) -> Option<DefId> { |
e9174d1e SL |
1924 | self.impl_trait_ref(def_id).map(|tr| tr.def_id) |
1925 | } | |
1926 | ||
9fa01778 XL |
1927 | /// If the given defid describes a method belonging to an impl, returns the |
1928 | /// `DefId` of the impl that the method belongs to; otherwise, returns `None`. | |
a7813a04 | 1929 | pub fn impl_of_method(self, def_id: DefId) -> Option<DefId> { |
ba9703b0 | 1930 | self.opt_associated_item(def_id).and_then(|trait_item| match trait_item.container { |
dfeec247 XL |
1931 | TraitContainer(_) => None, |
1932 | ImplContainer(def_id) => Some(def_id), | |
1933 | }) | |
e9174d1e SL |
1934 | } |
1935 | ||
54a0048b SL |
1936 | /// Looks up the span of `impl_did` if the impl is local; otherwise returns `Err` |
1937 | /// with the name of the crate containing the impl. | |
476ff2be | 1938 | pub fn span_of_impl(self, impl_did: DefId) -> Result<Span, Symbol> { |
f9f354fc | 1939 | if let Some(impl_did) = impl_did.as_local() { |
3dfed10e | 1940 | let hir_id = self.hir().local_def_id_to_hir_id(impl_did); |
dc9dc135 | 1941 | Ok(self.hir().span(hir_id)) |
54a0048b | 1942 | } else { |
ea8adc8c | 1943 | Err(self.crate_name(impl_did.krate)) |
54a0048b SL |
1944 | } |
1945 | } | |
7cac9316 | 1946 | |
9fa01778 XL |
1947 | /// Hygienically compares a use-site name (`use_name`) for a field or an associated item with |
1948 | /// its supposed definition name (`def_name`). The method also needs `DefId` of the supposed | |
1949 | /// definition's parent/scope to perform comparison. | |
8faf50e0 | 1950 | pub fn hygienic_eq(self, use_name: Ident, def_name: Ident, def_parent_def_id: DefId) -> bool { |
dc9dc135 XL |
1951 | // We could use `Ident::eq` here, but we deliberately don't. The name |
1952 | // comparison fails frequently, and we want to avoid the expensive | |
ba9703b0 | 1953 | // `normalize_to_macros_2_0()` calls required for the span comparison whenever possible. |
dfeec247 XL |
1954 | use_name.name == def_name.name |
1955 | && use_name | |
1956 | .span | |
1957 | .ctxt() | |
17df50a5 | 1958 | .hygienic_eq(def_name.span.ctxt(), self.expn_that_defined(def_parent_def_id)) |
dc9dc135 XL |
1959 | } |
1960 | ||
1961 | pub fn adjust_ident(self, mut ident: Ident, scope: DefId) -> Ident { | |
17df50a5 | 1962 | ident.span.normalize_to_macros_2_0_and_adjust(self.expn_that_defined(scope)); |
dc9dc135 XL |
1963 | ident |
1964 | } | |
1965 | ||
dfeec247 XL |
1966 | pub fn adjust_ident_and_get_scope( |
1967 | self, | |
1968 | mut ident: Ident, | |
1969 | scope: DefId, | |
1970 | block: hir::HirId, | |
1971 | ) -> (Ident, DefId) { | |
136023e0 XL |
1972 | let scope = ident |
1973 | .span | |
1974 | .normalize_to_macros_2_0_and_adjust(self.expn_that_defined(scope)) | |
1975 | .and_then(|actual_expansion| actual_expansion.expn_data().parent_module) | |
1976 | .unwrap_or_else(|| self.parent_module(block).to_def_id()); | |
7cac9316 XL |
1977 | (ident, scope) |
1978 | } | |
a1dfa0c6 | 1979 | |
74b04a01 XL |
1980 | pub fn is_object_safe(self, key: DefId) -> bool { |
1981 | self.object_safety_violations(key).is_empty() | |
a1dfa0c6 XL |
1982 | } |
1983 | } | |
1984 | ||
a1dfa0c6 | 1985 | /// Yields the parent function's `DefId` if `def_id` is an `impl Trait` definition. |
dc9dc135 | 1986 | pub fn is_impl_trait_defn(tcx: TyCtxt<'_>, def_id: DefId) -> Option<DefId> { |
f9f354fc | 1987 | if let Some(def_id) = def_id.as_local() { |
3dfed10e | 1988 | if let Node::Item(item) = tcx.hir().get(tcx.hir().local_def_id_to_hir_id(def_id)) { |
e74abb32 | 1989 | if let hir::ItemKind::OpaqueTy(ref opaque_ty) = item.kind { |
416331ca | 1990 | return opaque_ty.impl_trait_fn; |
8faf50e0 XL |
1991 | } |
1992 | } | |
1993 | } | |
1994 | None | |
1995 | } | |
1996 | ||
5869c6ff XL |
1997 | pub fn int_ty(ity: ast::IntTy) -> IntTy { |
1998 | match ity { | |
1999 | ast::IntTy::Isize => IntTy::Isize, | |
2000 | ast::IntTy::I8 => IntTy::I8, | |
2001 | ast::IntTy::I16 => IntTy::I16, | |
2002 | ast::IntTy::I32 => IntTy::I32, | |
2003 | ast::IntTy::I64 => IntTy::I64, | |
2004 | ast::IntTy::I128 => IntTy::I128, | |
2005 | } | |
2006 | } | |
2007 | ||
2008 | pub fn uint_ty(uty: ast::UintTy) -> UintTy { | |
2009 | match uty { | |
2010 | ast::UintTy::Usize => UintTy::Usize, | |
2011 | ast::UintTy::U8 => UintTy::U8, | |
2012 | ast::UintTy::U16 => UintTy::U16, | |
2013 | ast::UintTy::U32 => UintTy::U32, | |
2014 | ast::UintTy::U64 => UintTy::U64, | |
2015 | ast::UintTy::U128 => UintTy::U128, | |
2016 | } | |
2017 | } | |
2018 | ||
2019 | pub fn float_ty(fty: ast::FloatTy) -> FloatTy { | |
2020 | match fty { | |
2021 | ast::FloatTy::F32 => FloatTy::F32, | |
2022 | ast::FloatTy::F64 => FloatTy::F64, | |
2023 | } | |
2024 | } | |
2025 | ||
2026 | pub fn ast_int_ty(ity: IntTy) -> ast::IntTy { | |
2027 | match ity { | |
2028 | IntTy::Isize => ast::IntTy::Isize, | |
2029 | IntTy::I8 => ast::IntTy::I8, | |
2030 | IntTy::I16 => ast::IntTy::I16, | |
2031 | IntTy::I32 => ast::IntTy::I32, | |
2032 | IntTy::I64 => ast::IntTy::I64, | |
2033 | IntTy::I128 => ast::IntTy::I128, | |
2034 | } | |
2035 | } | |
2036 | ||
2037 | pub fn ast_uint_ty(uty: UintTy) -> ast::UintTy { | |
2038 | match uty { | |
2039 | UintTy::Usize => ast::UintTy::Usize, | |
2040 | UintTy::U8 => ast::UintTy::U8, | |
2041 | UintTy::U16 => ast::UintTy::U16, | |
2042 | UintTy::U32 => ast::UintTy::U32, | |
2043 | UintTy::U64 => ast::UintTy::U64, | |
2044 | UintTy::U128 => ast::UintTy::U128, | |
2045 | } | |
2046 | } | |
2047 | ||
f035d41b | 2048 | pub fn provide(providers: &mut ty::query::Providers) { |
94222f64 | 2049 | closure::provide(providers); |
ea8adc8c | 2050 | context::provide(providers); |
abe05a73 | 2051 | erase_regions::provide(providers); |
ff7c6d11 | 2052 | layout::provide(providers); |
3dfed10e | 2053 | util::provide(providers); |
1b1a35ee | 2054 | print::provide(providers); |
ba9703b0 | 2055 | super::util::bug::provide(providers); |
136023e0 | 2056 | super::middle::provide(providers); |
ba9703b0 XL |
2057 | *providers = ty::query::Providers { |
2058 | trait_impls_of: trait_def::trait_impls_of_provider, | |
5869c6ff | 2059 | type_uninhabited_from: inhabitedness::type_uninhabited_from, |
cdc7bbd5 | 2060 | const_param_default: consts::const_param_default, |
dc3f5686 | 2061 | vtable_allocation: vtable::vtable_allocation_provider, |
ba9703b0 XL |
2062 | ..*providers |
2063 | }; | |
cc61c64b XL |
2064 | } |
2065 | ||
cc61c64b XL |
2066 | /// A map for the local crate mapping each type to a vector of its |
2067 | /// inherent impls. This is not meant to be used outside of coherence; | |
2068 | /// rather, you should request the vector for a specific type via | |
7cac9316 XL |
2069 | /// `tcx.inherent_impls(def_id)` so as to minimize your dependencies |
2070 | /// (constructing this map requires touching the entire crate). | |
532ac7d7 | 2071 | #[derive(Clone, Debug, Default, HashStable)] |
cc61c64b | 2072 | pub struct CrateInherentImpls { |
17df50a5 | 2073 | pub inherent_impls: LocalDefIdMap<Vec<DefId>>, |
cc61c64b XL |
2074 | } |
2075 | ||
3dfed10e XL |
2076 | #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, TyEncodable, HashStable)] |
2077 | pub struct SymbolName<'tcx> { | |
2078 | /// `&str` gives a consistent ordering, which ensures reproducible builds. | |
2079 | pub name: &'tcx str, | |
7cac9316 XL |
2080 | } |
2081 | ||
3dfed10e XL |
2082 | impl<'tcx> SymbolName<'tcx> { |
2083 | pub fn new(tcx: TyCtxt<'tcx>, name: &str) -> SymbolName<'tcx> { | |
2084 | SymbolName { | |
2085 | name: unsafe { str::from_utf8_unchecked(tcx.arena.alloc_slice(name.as_bytes())) }, | |
2086 | } | |
e74abb32 XL |
2087 | } |
2088 | } | |
2089 | ||
3dfed10e | 2090 | impl<'tcx> fmt::Display for SymbolName<'tcx> { |
0bf4aa26 | 2091 | fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { |
7cac9316 XL |
2092 | fmt::Display::fmt(&self.name, fmt) |
2093 | } | |
2094 | } | |
0531ce1d | 2095 | |
3dfed10e | 2096 | impl<'tcx> fmt::Debug for SymbolName<'tcx> { |
0bf4aa26 | 2097 | fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { |
0531ce1d XL |
2098 | fmt::Display::fmt(&self.name, fmt) |
2099 | } | |
2100 | } | |
c295e0f8 XL |
2101 | |
2102 | #[derive(Debug, Default, Copy, Clone)] | |
2103 | pub struct FoundRelationships { | |
2104 | /// This is true if we identified that this Ty (`?T`) is found in a `?T: Foo` | |
2105 | /// obligation, where: | |
2106 | /// | |
2107 | /// * `Foo` is not `Sized` | |
2108 | /// * `(): Foo` may be satisfied | |
2109 | pub self_in_trait: bool, | |
2110 | /// This is true if we identified that this Ty (`?T`) is found in a `<_ as | |
2111 | /// _>::AssocType = ?T` | |
2112 | pub output: bool, | |
2113 | } |