1 // Each of these queries corresponds to a function pointer field in the
2 // `Providers` struct for requesting a value of that type, and a method
3 // on `tcx: TyCtxt` (and `tcx.at(span)`) for doing that request in a way
4 // which memoizes and does dep-graph tracking, wrapping around the actual
5 // `Providers` that the driver creates (using several `rustc_*` crates).
7 // The result type of each query must implement `Clone`, and additionally
8 // `ty::query::values::Value`, which produces an appropriate placeholder
9 // (error) value if the query resulted in a query cycle.
10 // Queries marked with `fatal_cycle` do not need the latter implementation,
11 // as they will raise an fatal error on query cycles instead.
13 query trigger_delay_span_bug(key: DefId) -> () {
14 desc { "trigger a delay span bug" }
17 query resolutions(_: ()) -> &'tcx ty::ResolverOutputs {
20 desc { "get the resolver outputs" }
23 /// Represents crate as a whole (as distinct from the top-level crate module).
24 /// If you call `hir_crate` (e.g., indirectly by calling `tcx.hir().krate()`),
25 /// we will have to assume that any change means that you need to be recompiled.
26 /// This is because the `hir_crate` query gives you access to all other items.
27 /// To avoid this fate, do not call `tcx.hir().krate()`; instead,
28 /// prefer wrappers like `tcx.visit_all_items_in_krate()`.
29 query hir_crate(key: ()) -> &'tcx Crate<'tcx> {
32 desc { "get the crate HIR" }
35 /// The indexed HIR. This can be conveniently accessed by `tcx.hir()`.
36 /// Avoid calling this query directly.
37 query index_hir(_: ()) -> &'tcx crate::hir::IndexedHir<'tcx> {
43 /// The items in a module.
45 /// This can be conveniently accessed by `tcx.hir().visit_item_likes_in_module`.
46 /// Avoid calling this query directly.
47 query hir_module_items(key: LocalDefId) -> &'tcx hir::ModuleItems {
49 desc { |tcx| "HIR module items in `{}`", tcx.def_path_str(key.to_def_id()) }
52 /// Gives access to the HIR node for the HIR owner `key`.
54 /// This can be conveniently accessed by methods on `tcx.hir()`.
55 /// Avoid calling this query directly.
56 query hir_owner(key: LocalDefId) -> Option<crate::hir::Owner<'tcx>> {
58 desc { |tcx| "HIR owner of `{}`", tcx.def_path_str(key.to_def_id()) }
61 /// Gives access to the HIR node's parent for the HIR owner `key`.
63 /// This can be conveniently accessed by methods on `tcx.hir()`.
64 /// Avoid calling this query directly.
65 query hir_owner_parent(key: LocalDefId) -> hir::HirId {
67 desc { |tcx| "HIR parent of `{}`", tcx.def_path_str(key.to_def_id()) }
70 /// Gives access to the HIR nodes and bodies inside the HIR owner `key`.
72 /// This can be conveniently accessed by methods on `tcx.hir()`.
73 /// Avoid calling this query directly.
74 query hir_owner_nodes(key: LocalDefId) -> Option<&'tcx crate::hir::OwnerNodes<'tcx>> {
76 desc { |tcx| "HIR owner items in `{}`", tcx.def_path_str(key.to_def_id()) }
79 /// Gives access to the HIR attributes inside the HIR owner `key`.
81 /// This can be conveniently accessed by methods on `tcx.hir()`.
82 /// Avoid calling this query directly.
83 query hir_attrs(key: LocalDefId) -> rustc_middle::hir::AttributeMap<'tcx> {
85 desc { |tcx| "HIR owner attributes in `{}`", tcx.def_path_str(key.to_def_id()) }
88 /// Computes the `DefId` of the corresponding const parameter in case the `key` is a
89 /// const argument and returns `None` otherwise.
91 /// ```ignore (incomplete)
92 /// let a = foo::<7>();
93 /// // ^ Calling `opt_const_param_of` for this argument,
95 /// fn foo<const N: usize>()
96 /// // ^ returns this `DefId`.
99 /// // ^ While calling `opt_const_param_of` for other bodies returns `None`.
102 // It looks like caching this query on disk actually slightly
103 // worsened performance in #74376.
105 // Once const generics are more prevalently used, we might want to
106 // consider only caching calls returning `Some`.
107 query opt_const_param_of(key: LocalDefId) -> Option<DefId> {
108 desc { |tcx| "computing the optional const parameter of `{}`", tcx.def_path_str(key.to_def_id()) }
111 /// Given the def_id of a const-generic parameter, computes the associated default const
112 /// parameter. e.g. `fn example<const N: usize=3>` called on `N` would return `3`.
113 query const_param_default(param: DefId) -> &'tcx ty::Const<'tcx> {
114 desc { |tcx| "compute const default for a given parameter `{}`", tcx.def_path_str(param) }
117 query default_anon_const_substs(key: DefId) -> SubstsRef<'tcx> {
118 desc { |tcx| "computing the default generic arguments for `{}`", tcx.def_path_str(key) }
121 /// Records the type of every item.
122 query type_of(key: DefId) -> Ty<'tcx> {
123 desc { |tcx| "computing type of `{}`", tcx.def_path_str(key) }
124 cache_on_disk_if { key.is_local() }
127 query analysis(key: ()) -> Result<(), ErrorReported> {
129 desc { "running analysis passes on this crate" }
132 /// Maps from the `DefId` of an item (trait/struct/enum/fn) to its
133 /// associated generics.
134 query generics_of(key: DefId) -> ty::Generics {
135 desc { |tcx| "computing generics of `{}`", tcx.def_path_str(key) }
136 storage(ArenaCacheSelector<'tcx>)
137 cache_on_disk_if { key.is_local() }
140 /// Maps from the `DefId` of an item (trait/struct/enum/fn) to the
141 /// predicates (where-clauses) that must be proven true in order
142 /// to reference it. This is almost always the "predicates query"
145 /// `predicates_of` builds on `predicates_defined_on` -- in fact,
146 /// it is almost always the same as that query, except for the
147 /// case of traits. For traits, `predicates_of` contains
148 /// an additional `Self: Trait<...>` predicate that users don't
149 /// actually write. This reflects the fact that to invoke the
150 /// trait (e.g., via `Default::default`) you must supply types
151 /// that actually implement the trait. (However, this extra
152 /// predicate gets in the way of some checks, which are intended
153 /// to operate over only the actual where-clauses written by the
155 query predicates_of(key: DefId) -> ty::GenericPredicates<'tcx> {
156 desc { |tcx| "computing predicates of `{}`", tcx.def_path_str(key) }
157 cache_on_disk_if { key.is_local() }
160 /// Returns the list of bounds that can be used for
161 /// `SelectionCandidate::ProjectionCandidate(_)` and
162 /// `ProjectionTyCandidate::TraitDef`.
163 /// Specifically this is the bounds written on the trait's type
164 /// definition, or those after the `impl` keyword
166 /// ```ignore (incomplete)
167 /// type X: Bound + 'lt
169 /// impl Debug + Display
170 /// // ^^^^^^^^^^^^^^^
173 /// `key` is the `DefId` of the associated type or opaque type.
175 /// Bounds from the parent (e.g. with nested impl trait) are not included.
176 query explicit_item_bounds(key: DefId) -> &'tcx [(ty::Predicate<'tcx>, Span)] {
177 desc { |tcx| "finding item bounds for `{}`", tcx.def_path_str(key) }
180 /// Elaborated version of the predicates from `explicit_item_bounds`.
186 /// type MyAType: Eq + ?Sized;
190 /// `explicit_item_bounds` returns `[<Self as MyTrait>::MyAType: Eq]`,
191 /// and `item_bounds` returns
194 /// <Self as Trait>::MyAType: Eq,
195 /// <Self as Trait>::MyAType: PartialEq<<Self as Trait>::MyAType>
199 /// Bounds from the parent (e.g. with nested impl trait) are not included.
200 query item_bounds(key: DefId) -> &'tcx ty::List<ty::Predicate<'tcx>> {
201 desc { |tcx| "elaborating item bounds for `{}`", tcx.def_path_str(key) }
204 query native_libraries(_: CrateNum) -> Lrc<Vec<NativeLib>> {
205 desc { "looking up the native libraries of a linked crate" }
208 query lint_levels(_: ()) -> LintLevelMap {
209 storage(ArenaCacheSelector<'tcx>)
211 desc { "computing the lint levels for items in this crate" }
214 query parent_module_from_def_id(key: LocalDefId) -> LocalDefId {
216 desc { |tcx| "parent module of `{}`", tcx.def_path_str(key.to_def_id()) }
219 query expn_that_defined(key: DefId) -> rustc_span::ExpnId {
220 // This query reads from untracked data in definitions.
222 desc { |tcx| "expansion that defined `{}`", tcx.def_path_str(key) }
225 query is_panic_runtime(_: CrateNum) -> bool {
227 desc { "checking if the crate is_panic_runtime" }
230 /// Fetch the THIR for a given body. If typeck for that body failed, returns an empty `Thir`.
231 query thir_body(key: ty::WithOptConstParam<LocalDefId>) -> (&'tcx Steal<thir::Thir<'tcx>>, thir::ExprId) {
232 // Perf tests revealed that hashing THIR is inefficient (see #85729).
234 desc { |tcx| "building THIR for `{}`", tcx.def_path_str(key.did.to_def_id()) }
237 /// Create a THIR tree for debugging.
238 query thir_tree(key: ty::WithOptConstParam<LocalDefId>) -> String {
240 desc { |tcx| "constructing THIR tree for `{}`", tcx.def_path_str(key.did.to_def_id()) }
243 /// Set of all the `DefId`s in this crate that have MIR associated with
244 /// them. This includes all the body owners, but also things like struct
246 query mir_keys(_: ()) -> FxHashSet<LocalDefId> {
247 storage(ArenaCacheSelector<'tcx>)
248 desc { "getting a list of all mir_keys" }
251 /// Maps DefId's that have an associated `mir::Body` to the result
252 /// of the MIR const-checking pass. This is the set of qualifs in
253 /// the final value of a `const`.
254 query mir_const_qualif(key: DefId) -> mir::ConstQualifs {
255 desc { |tcx| "const checking `{}`", tcx.def_path_str(key) }
256 cache_on_disk_if { key.is_local() }
258 query mir_const_qualif_const_arg(
259 key: (LocalDefId, DefId)
260 ) -> mir::ConstQualifs {
262 |tcx| "const checking the const argument `{}`",
263 tcx.def_path_str(key.0.to_def_id())
267 /// Fetch the MIR for a given `DefId` right after it's built - this includes
268 /// unreachable code.
269 query mir_built(key: ty::WithOptConstParam<LocalDefId>) -> &'tcx Steal<mir::Body<'tcx>> {
270 desc { |tcx| "building MIR for `{}`", tcx.def_path_str(key.did.to_def_id()) }
273 /// Fetch the MIR for a given `DefId` up till the point where it is
274 /// ready for const qualification.
276 /// See the README for the `mir` module for details.
277 query mir_const(key: ty::WithOptConstParam<LocalDefId>) -> &'tcx Steal<mir::Body<'tcx>> {
279 |tcx| "processing MIR for {}`{}`",
280 if key.const_param_did.is_some() { "the const argument " } else { "" },
281 tcx.def_path_str(key.did.to_def_id()),
286 /// Try to build an abstract representation of the given constant.
287 query mir_abstract_const(
289 ) -> Result<Option<&'tcx [mir::abstract_const::Node<'tcx>]>, ErrorReported> {
291 |tcx| "building an abstract representation for {}", tcx.def_path_str(key),
294 /// Try to build an abstract representation of the given constant.
295 query mir_abstract_const_of_const_arg(
296 key: (LocalDefId, DefId)
297 ) -> Result<Option<&'tcx [mir::abstract_const::Node<'tcx>]>, ErrorReported> {
300 "building an abstract representation for the const argument {}",
301 tcx.def_path_str(key.0.to_def_id()),
305 query try_unify_abstract_consts(key: (
306 ty::Unevaluated<'tcx, ()>, ty::Unevaluated<'tcx, ()>
309 |tcx| "trying to unify the generic constants {} and {}",
310 tcx.def_path_str(key.0.def.did), tcx.def_path_str(key.1.def.did)
314 query mir_drops_elaborated_and_const_checked(
315 key: ty::WithOptConstParam<LocalDefId>
316 ) -> &'tcx Steal<mir::Body<'tcx>> {
318 desc { |tcx| "elaborating drops for `{}`", tcx.def_path_str(key.did.to_def_id()) }
323 ) -> &'tcx mir::Body<'tcx> {
324 desc { |tcx| "caching mir of `{}` for CTFE", tcx.def_path_str(key) }
325 cache_on_disk_if { key.is_local() }
328 query mir_for_ctfe_of_const_arg(key: (LocalDefId, DefId)) -> &'tcx mir::Body<'tcx> {
330 |tcx| "MIR for CTFE of the const argument `{}`",
331 tcx.def_path_str(key.0.to_def_id())
335 query mir_promoted(key: ty::WithOptConstParam<LocalDefId>) ->
337 &'tcx Steal<mir::Body<'tcx>>,
338 &'tcx Steal<IndexVec<mir::Promoted, mir::Body<'tcx>>>
342 |tcx| "processing {}`{}`",
343 if key.const_param_did.is_some() { "the const argument " } else { "" },
344 tcx.def_path_str(key.did.to_def_id()),
348 query symbols_for_closure_captures(
349 key: (LocalDefId, DefId)
350 ) -> Vec<rustc_span::Symbol> {
352 |tcx| "symbols for captures of closure `{}` in `{}`",
353 tcx.def_path_str(key.1),
354 tcx.def_path_str(key.0.to_def_id())
358 /// MIR after our optimization passes have run. This is MIR that is ready
359 /// for codegen. This is also the only query that can fetch non-local MIR, at present.
360 query optimized_mir(key: DefId) -> &'tcx mir::Body<'tcx> {
361 desc { |tcx| "optimizing MIR for `{}`", tcx.def_path_str(key) }
362 cache_on_disk_if { key.is_local() }
365 /// Returns coverage summary info for a function, after executing the `InstrumentCoverage`
366 /// MIR pass (assuming the -Zinstrument-coverage option is enabled).
367 query coverageinfo(key: ty::InstanceDef<'tcx>) -> mir::CoverageInfo {
368 desc { |tcx| "retrieving coverage info from MIR for `{}`", tcx.def_path_str(key.def_id()) }
369 storage(ArenaCacheSelector<'tcx>)
372 /// Returns the name of the file that contains the function body, if instrumented for coverage.
373 query covered_file_name(key: DefId) -> Option<Symbol> {
375 |tcx| "retrieving the covered file name, if instrumented, for `{}`",
376 tcx.def_path_str(key)
378 storage(ArenaCacheSelector<'tcx>)
379 cache_on_disk_if { key.is_local() }
382 /// Returns the `CodeRegions` for a function that has instrumented coverage, in case the
383 /// function was optimized out before codegen, and before being added to the Coverage Map.
384 query covered_code_regions(key: DefId) -> Vec<&'tcx mir::coverage::CodeRegion> {
386 |tcx| "retrieving the covered `CodeRegion`s, if instrumented, for `{}`",
387 tcx.def_path_str(key)
389 storage(ArenaCacheSelector<'tcx>)
390 cache_on_disk_if { key.is_local() }
393 /// The `DefId` is the `DefId` of the containing MIR body. Promoteds do not have their own
394 /// `DefId`. This function returns all promoteds in the specified body. The body references
395 /// promoteds by the `DefId` and the `mir::Promoted` index. This is necessary, because
396 /// after inlining a body may refer to promoteds from other bodies. In that case you still
397 /// need to use the `DefId` of the original body.
398 query promoted_mir(key: DefId) -> &'tcx IndexVec<mir::Promoted, mir::Body<'tcx>> {
399 desc { |tcx| "optimizing promoted MIR for `{}`", tcx.def_path_str(key) }
400 cache_on_disk_if { key.is_local() }
402 query promoted_mir_of_const_arg(
403 key: (LocalDefId, DefId)
404 ) -> &'tcx IndexVec<mir::Promoted, mir::Body<'tcx>> {
406 |tcx| "optimizing promoted MIR for the const argument `{}`",
407 tcx.def_path_str(key.0.to_def_id()),
411 /// Erases regions from `ty` to yield a new type.
412 /// Normally you would just use `tcx.erase_regions(value)`,
413 /// however, which uses this query as a kind of cache.
414 query erase_regions_ty(ty: Ty<'tcx>) -> Ty<'tcx> {
415 // This query is not expected to have input -- as a result, it
416 // is not a good candidates for "replay" because it is essentially a
417 // pure function of its input (and hence the expectation is that
418 // no caller would be green **apart** from just these
419 // queries). Making it anonymous avoids hashing the result, which
420 // may save a bit of time.
422 desc { "erasing regions from `{:?}`", ty }
425 query wasm_import_module_map(_: CrateNum) -> FxHashMap<DefId, String> {
426 storage(ArenaCacheSelector<'tcx>)
427 desc { "wasm import module map" }
430 /// Maps from the `DefId` of an item (trait/struct/enum/fn) to the
431 /// predicates (where-clauses) directly defined on it. This is
432 /// equal to the `explicit_predicates_of` predicates plus the
433 /// `inferred_outlives_of` predicates.
434 query predicates_defined_on(key: DefId) -> ty::GenericPredicates<'tcx> {
435 desc { |tcx| "computing predicates of `{}`", tcx.def_path_str(key) }
438 /// Returns everything that looks like a predicate written explicitly
439 /// by the user on a trait item.
441 /// Traits are unusual, because predicates on associated types are
442 /// converted into bounds on that type for backwards compatibility:
444 /// trait X where Self::U: Copy { type U; }
448 /// trait X { type U: Copy; }
450 /// `explicit_predicates_of` and `explicit_item_bounds` will then take
451 /// the appropriate subsets of the predicates here.
452 query trait_explicit_predicates_and_bounds(key: LocalDefId) -> ty::GenericPredicates<'tcx> {
453 desc { |tcx| "computing explicit predicates of trait `{}`", tcx.def_path_str(key.to_def_id()) }
456 /// Returns the predicates written explicitly by the user.
457 query explicit_predicates_of(key: DefId) -> ty::GenericPredicates<'tcx> {
458 desc { |tcx| "computing explicit predicates of `{}`", tcx.def_path_str(key) }
461 /// Returns the inferred outlives predicates (e.g., for `struct
462 /// Foo<'a, T> { x: &'a T }`, this would return `T: 'a`).
463 query inferred_outlives_of(key: DefId) -> &'tcx [(ty::Predicate<'tcx>, Span)] {
464 desc { |tcx| "computing inferred outlives predicates of `{}`", tcx.def_path_str(key) }
467 /// Maps from the `DefId` of a trait to the list of
468 /// super-predicates. This is a subset of the full list of
469 /// predicates. We store these in a separate map because we must
470 /// evaluate them even during type conversion, often before the
471 /// full predicates are available (note that supertraits have
472 /// additional acyclicity requirements).
473 query super_predicates_of(key: DefId) -> ty::GenericPredicates<'tcx> {
474 desc { |tcx| "computing the super predicates of `{}`", tcx.def_path_str(key) }
477 /// The `Option<Ident>` is the name of an associated type. If it is `None`, then this query
478 /// returns the full set of predicates. If `Some<Ident>`, then the query returns only the
479 /// subset of super-predicates that reference traits that define the given associated type.
480 /// This is used to avoid cycles in resolving types like `T::Item`.
481 query super_predicates_that_define_assoc_type(key: (DefId, Option<rustc_span::symbol::Ident>)) -> ty::GenericPredicates<'tcx> {
482 desc { |tcx| "computing the super traits of `{}`{}",
483 tcx.def_path_str(key.0),
484 if let Some(assoc_name) = key.1 { format!(" with associated type name `{}`", assoc_name) } else { "".to_string() },
488 /// To avoid cycles within the predicates of a single item we compute
489 /// per-type-parameter predicates for resolving `T::AssocTy`.
490 query type_param_predicates(key: (DefId, LocalDefId, rustc_span::symbol::Ident)) -> ty::GenericPredicates<'tcx> {
491 desc { |tcx| "computing the bounds for type parameter `{}`", {
492 let id = tcx.hir().local_def_id_to_hir_id(key.1);
493 tcx.hir().ty_param_name(id)
497 query trait_def(key: DefId) -> ty::TraitDef {
498 desc { |tcx| "computing trait definition for `{}`", tcx.def_path_str(key) }
499 storage(ArenaCacheSelector<'tcx>)
501 query adt_def(key: DefId) -> &'tcx ty::AdtDef {
502 desc { |tcx| "computing ADT definition for `{}`", tcx.def_path_str(key) }
504 query adt_destructor(key: DefId) -> Option<ty::Destructor> {
505 desc { |tcx| "computing `Drop` impl for `{}`", tcx.def_path_str(key) }
508 // The cycle error here should be reported as an error by `check_representable`.
509 // We consider the type as Sized in the meanwhile to avoid
510 // further errors (done in impl Value for AdtSizedConstraint).
511 // Use `cycle_delay_bug` to delay the cycle error here to be emitted later
512 // in case we accidentally otherwise don't emit an error.
513 query adt_sized_constraint(
515 ) -> AdtSizedConstraint<'tcx> {
516 desc { |tcx| "computing `Sized` constraints for `{}`", tcx.def_path_str(key) }
520 query adt_dtorck_constraint(
522 ) -> Result<DtorckConstraint<'tcx>, NoSolution> {
523 desc { |tcx| "computing drop-check constraints for `{}`", tcx.def_path_str(key) }
526 /// Returns `true` if this is a const fn, use the `is_const_fn` to know whether your crate
527 /// actually sees it as const fn (e.g., the const-fn-ness might be unstable and you might
528 /// not have the feature gate active).
530 /// **Do not call this function manually.** It is only meant to cache the base data for the
531 /// `is_const_fn` function.
532 query is_const_fn_raw(key: DefId) -> bool {
533 desc { |tcx| "checking if item is const fn: `{}`", tcx.def_path_str(key) }
536 /// Returns `true` if this is a const `impl`. **Do not call this function manually.**
538 /// This query caches the base data for the `is_const_impl` helper function, which also
539 /// takes into account stability attributes (e.g., `#[rustc_const_unstable]`).
540 query is_const_impl_raw(key: DefId) -> bool {
541 desc { |tcx| "checking if item is const impl: `{}`", tcx.def_path_str(key) }
544 query asyncness(key: DefId) -> hir::IsAsync {
545 desc { |tcx| "checking if the function is async: `{}`", tcx.def_path_str(key) }
548 /// Returns `true` if calls to the function may be promoted.
550 /// This is either because the function is e.g., a tuple-struct or tuple-variant
551 /// constructor, or because it has the `#[rustc_promotable]` attribute. The attribute should
552 /// be removed in the future in favour of some form of check which figures out whether the
553 /// function does not inspect the bits of any of its arguments (so is essentially just a
554 /// constructor function).
555 query is_promotable_const_fn(key: DefId) -> bool {
556 desc { |tcx| "checking if item is promotable: `{}`", tcx.def_path_str(key) }
559 /// Returns `true` if this is a foreign item (i.e., linked via `extern { ... }`).
560 query is_foreign_item(key: DefId) -> bool {
561 desc { |tcx| "checking if `{}` is a foreign item", tcx.def_path_str(key) }
564 /// Returns `Some(mutability)` if the node pointed to by `def_id` is a static item.
565 query static_mutability(def_id: DefId) -> Option<hir::Mutability> {
566 desc { |tcx| "looking up static mutability of `{}`", tcx.def_path_str(def_id) }
569 /// Returns `Some(generator_kind)` if the node pointed to by `def_id` is a generator.
570 query generator_kind(def_id: DefId) -> Option<hir::GeneratorKind> {
571 desc { |tcx| "looking up generator kind of `{}`", tcx.def_path_str(def_id) }
574 /// Gets a map with the variance of every item; use `item_variance` instead.
575 query crate_variances(_: ()) -> ty::CrateVariancesMap<'tcx> {
576 storage(ArenaCacheSelector<'tcx>)
577 desc { "computing the variances for items in this crate" }
580 /// Maps from the `DefId` of a type or region parameter to its (inferred) variance.
581 query variances_of(def_id: DefId) -> &'tcx [ty::Variance] {
582 desc { |tcx| "computing the variances of `{}`", tcx.def_path_str(def_id) }
585 /// Maps from thee `DefId` of a type to its (inferred) outlives.
586 query inferred_outlives_crate(_: ()) -> ty::CratePredicatesMap<'tcx> {
587 storage(ArenaCacheSelector<'tcx>)
588 desc { "computing the inferred outlives predicates for items in this crate" }
591 /// Maps from an impl/trait `DefId to a list of the `DefId`s of its items.
592 query associated_item_def_ids(key: DefId) -> &'tcx [DefId] {
593 desc { |tcx| "collecting associated items of `{}`", tcx.def_path_str(key) }
596 /// Maps from a trait item to the trait item "descriptor".
597 query associated_item(key: DefId) -> ty::AssocItem {
598 desc { |tcx| "computing associated item data for `{}`", tcx.def_path_str(key) }
599 storage(ArenaCacheSelector<'tcx>)
602 /// Collects the associated items defined on a trait or impl.
603 query associated_items(key: DefId) -> ty::AssocItems<'tcx> {
604 storage(ArenaCacheSelector<'tcx>)
605 desc { |tcx| "collecting associated items of {}", tcx.def_path_str(key) }
608 /// Given an `impl_id`, return the trait it implements.
609 /// Return `None` if this is an inherent impl.
610 query impl_trait_ref(impl_id: DefId) -> Option<ty::TraitRef<'tcx>> {
611 desc { |tcx| "computing trait implemented by `{}`", tcx.def_path_str(impl_id) }
613 query impl_polarity(impl_id: DefId) -> ty::ImplPolarity {
614 desc { |tcx| "computing implementation polarity of `{}`", tcx.def_path_str(impl_id) }
617 query issue33140_self_ty(key: DefId) -> Option<ty::Ty<'tcx>> {
618 desc { |tcx| "computing Self type wrt issue #33140 `{}`", tcx.def_path_str(key) }
621 /// Maps a `DefId` of a type to a list of its inherent impls.
622 /// Contains implementations of methods that are inherent to a type.
623 /// Methods in these implementations don't need to be exported.
624 query inherent_impls(key: DefId) -> &'tcx [DefId] {
625 desc { |tcx| "collecting inherent impls for `{}`", tcx.def_path_str(key) }
629 /// The result of unsafety-checking this `LocalDefId`.
630 query unsafety_check_result(key: LocalDefId) -> &'tcx mir::UnsafetyCheckResult {
631 desc { |tcx| "unsafety-checking `{}`", tcx.def_path_str(key.to_def_id()) }
632 cache_on_disk_if { true }
634 query unsafety_check_result_for_const_arg(key: (LocalDefId, DefId)) -> &'tcx mir::UnsafetyCheckResult {
636 |tcx| "unsafety-checking the const argument `{}`",
637 tcx.def_path_str(key.0.to_def_id())
641 /// Unsafety-check this `LocalDefId` with THIR unsafeck. This should be
642 /// used with `-Zthir-unsafeck`.
643 query thir_check_unsafety(key: LocalDefId) {
644 desc { |tcx| "unsafety-checking `{}`", tcx.def_path_str(key.to_def_id()) }
645 cache_on_disk_if { true }
647 query thir_check_unsafety_for_const_arg(key: (LocalDefId, DefId)) {
649 |tcx| "unsafety-checking the const argument `{}`",
650 tcx.def_path_str(key.0.to_def_id())
654 /// HACK: when evaluated, this reports an "unsafe derive on repr(packed)" error.
656 /// Unsafety checking is executed for each method separately, but we only want
657 /// to emit this error once per derive. As there are some impls with multiple
658 /// methods, we use a query for deduplication.
659 query unsafe_derive_on_repr_packed(key: LocalDefId) -> () {
660 desc { |tcx| "processing `{}`", tcx.def_path_str(key.to_def_id()) }
663 /// The signature of functions.
664 query fn_sig(key: DefId) -> ty::PolyFnSig<'tcx> {
665 desc { |tcx| "computing function signature of `{}`", tcx.def_path_str(key) }
668 query lint_mod(key: LocalDefId) -> () {
669 desc { |tcx| "linting {}", describe_as_module(key, tcx) }
672 /// Checks the attributes in the module.
673 query check_mod_attrs(key: LocalDefId) -> () {
674 desc { |tcx| "checking attributes in {}", describe_as_module(key, tcx) }
677 query check_mod_unstable_api_usage(key: LocalDefId) -> () {
678 desc { |tcx| "checking for unstable API usage in {}", describe_as_module(key, tcx) }
681 /// Checks the const bodies in the module for illegal operations (e.g. `if` or `loop`).
682 query check_mod_const_bodies(key: LocalDefId) -> () {
683 desc { |tcx| "checking consts in {}", describe_as_module(key, tcx) }
686 /// Checks the loops in the module.
687 query check_mod_loops(key: LocalDefId) -> () {
688 desc { |tcx| "checking loops in {}", describe_as_module(key, tcx) }
691 query check_mod_naked_functions(key: LocalDefId) -> () {
692 desc { |tcx| "checking naked functions in {}", describe_as_module(key, tcx) }
695 query check_mod_item_types(key: LocalDefId) -> () {
696 desc { |tcx| "checking item types in {}", describe_as_module(key, tcx) }
699 query check_mod_privacy(key: LocalDefId) -> () {
700 desc { |tcx| "checking privacy in {}", describe_as_module(key, tcx) }
703 query check_mod_intrinsics(key: LocalDefId) -> () {
704 desc { |tcx| "checking intrinsics in {}", describe_as_module(key, tcx) }
707 query check_mod_liveness(key: LocalDefId) -> () {
708 desc { |tcx| "checking liveness of variables in {}", describe_as_module(key, tcx) }
711 query check_mod_impl_wf(key: LocalDefId) -> () {
712 desc { |tcx| "checking that impls are well-formed in {}", describe_as_module(key, tcx) }
715 query collect_mod_item_types(key: LocalDefId) -> () {
716 desc { |tcx| "collecting item types in {}", describe_as_module(key, tcx) }
719 /// Caches `CoerceUnsized` kinds for impls on custom types.
720 query coerce_unsized_info(key: DefId)
721 -> ty::adjustment::CoerceUnsizedInfo {
722 desc { |tcx| "computing CoerceUnsized info for `{}`", tcx.def_path_str(key) }
725 query typeck_item_bodies(_: ()) -> () {
726 desc { "type-checking all item bodies" }
729 query typeck(key: LocalDefId) -> &'tcx ty::TypeckResults<'tcx> {
730 desc { |tcx| "type-checking `{}`", tcx.def_path_str(key.to_def_id()) }
731 cache_on_disk_if { true }
733 query typeck_const_arg(
734 key: (LocalDefId, DefId)
735 ) -> &'tcx ty::TypeckResults<'tcx> {
737 |tcx| "type-checking the const argument `{}`",
738 tcx.def_path_str(key.0.to_def_id()),
741 query diagnostic_only_typeck(key: LocalDefId) -> &'tcx ty::TypeckResults<'tcx> {
742 desc { |tcx| "type-checking `{}`", tcx.def_path_str(key.to_def_id()) }
743 cache_on_disk_if { true }
744 load_cached(tcx, id) {
745 let typeck_results: Option<ty::TypeckResults<'tcx>> = tcx
746 .on_disk_cache().as_ref()
747 .and_then(|c| c.try_load_query_result(*tcx, id));
749 typeck_results.map(|x| &*tcx.arena.alloc(x))
753 query used_trait_imports(key: LocalDefId) -> &'tcx FxHashSet<LocalDefId> {
754 desc { |tcx| "used_trait_imports `{}`", tcx.def_path_str(key.to_def_id()) }
755 cache_on_disk_if { true }
758 query has_typeck_results(def_id: DefId) -> bool {
759 desc { |tcx| "checking whether `{}` has a body", tcx.def_path_str(def_id) }
762 query coherent_trait(def_id: DefId) -> () {
763 desc { |tcx| "coherence checking all impls of trait `{}`", tcx.def_path_str(def_id) }
766 /// Borrow-checks the function body. If this is a closure, returns
767 /// additional requirements that the closure's creator must verify.
768 query mir_borrowck(key: LocalDefId) -> &'tcx mir::BorrowCheckResult<'tcx> {
769 desc { |tcx| "borrow-checking `{}`", tcx.def_path_str(key.to_def_id()) }
770 cache_on_disk_if(tcx, opt_result) {
771 tcx.is_closure(key.to_def_id())
772 || opt_result.map_or(false, |r| !r.concrete_opaque_types.is_empty())
775 query mir_borrowck_const_arg(key: (LocalDefId, DefId)) -> &'tcx mir::BorrowCheckResult<'tcx> {
777 |tcx| "borrow-checking the const argument`{}`",
778 tcx.def_path_str(key.0.to_def_id())
782 /// Gets a complete map from all types to their inherent impls.
783 /// Not meant to be used directly outside of coherence.
784 query crate_inherent_impls(k: ()) -> CrateInherentImpls {
785 storage(ArenaCacheSelector<'tcx>)
787 desc { "all inherent impls defined in crate" }
790 /// Checks all types in the crate for overlap in their inherent impls. Reports errors.
791 /// Not meant to be used directly outside of coherence.
792 query crate_inherent_impls_overlap_check(_: ())
795 desc { "check for overlap between inherent impls defined in this crate" }
798 /// Check whether the function has any recursion that could cause the inliner to trigger
799 /// a cycle. Returns the call stack causing the cycle. The call stack does not contain the
800 /// current function, just all intermediate functions.
801 query mir_callgraph_reachable(key: (ty::Instance<'tcx>, LocalDefId)) -> bool {
804 "computing if `{}` (transitively) calls `{}`",
806 tcx.def_path_str(key.1.to_def_id()),
810 /// Obtain all the calls into other local functions
811 query mir_inliner_callees(key: ty::InstanceDef<'tcx>) -> &'tcx [(DefId, SubstsRef<'tcx>)] {
814 "computing all local function calls in `{}`",
815 tcx.def_path_str(key.def_id()),
819 /// Evaluates a constant and returns the computed allocation.
821 /// **Do not use this** directly, use the `tcx.eval_static_initializer` wrapper.
822 query eval_to_allocation_raw(key: ty::ParamEnvAnd<'tcx, GlobalId<'tcx>>)
823 -> EvalToAllocationRawResult<'tcx> {
825 "const-evaluating + checking `{}`",
826 key.value.display(tcx)
828 cache_on_disk_if { true }
831 /// Evaluates const items or anonymous constants
832 /// (such as enum variant explicit discriminants or array lengths)
833 /// into a representation suitable for the type system and const generics.
835 /// **Do not use this** directly, use one of the following wrappers: `tcx.const_eval_poly`,
836 /// `tcx.const_eval_resolve`, `tcx.const_eval_instance`, or `tcx.const_eval_global_id`.
837 query eval_to_const_value_raw(key: ty::ParamEnvAnd<'tcx, GlobalId<'tcx>>)
838 -> EvalToConstValueResult<'tcx> {
840 "simplifying constant for the type system `{}`",
841 key.value.display(tcx)
843 cache_on_disk_if { true }
846 /// Convert an evaluated constant to a type level constant or
847 /// return `None` if that is not possible.
848 query const_to_valtree(
849 key: ty::ParamEnvAnd<'tcx, ConstAlloc<'tcx>>
850 ) -> Option<ty::ValTree<'tcx>> {
851 desc { "destructure constant" }
854 /// Destructure a constant ADT or array into its variant index and its
856 query destructure_const(
857 key: ty::ParamEnvAnd<'tcx, &'tcx ty::Const<'tcx>>
858 ) -> mir::DestructuredConst<'tcx> {
859 desc { "destructure constant" }
862 /// Dereference a constant reference or raw pointer and turn the result into a constant
865 key: ty::ParamEnvAnd<'tcx, &'tcx ty::Const<'tcx>>
866 ) -> &'tcx ty::Const<'tcx> {
867 desc { "deref constant" }
870 query const_caller_location(key: (rustc_span::Symbol, u32, u32)) -> ConstValue<'tcx> {
871 desc { "get a &core::panic::Location referring to a span" }
875 key: LitToConstInput<'tcx>
876 ) -> Result<&'tcx ty::Const<'tcx>, LitToConstError> {
877 desc { "converting literal to const" }
880 query check_match(key: DefId) {
881 desc { |tcx| "match-checking `{}`", tcx.def_path_str(key) }
882 cache_on_disk_if { key.is_local() }
885 /// Performs part of the privacy check and computes "access levels".
886 query privacy_access_levels(_: ()) -> &'tcx AccessLevels {
888 desc { "privacy access levels" }
890 query check_private_in_public(_: ()) -> () {
892 desc { "checking for private elements in public interfaces" }
895 query reachable_set(_: ()) -> FxHashSet<LocalDefId> {
896 storage(ArenaCacheSelector<'tcx>)
897 desc { "reachability" }
900 /// Per-body `region::ScopeTree`. The `DefId` should be the owner `DefId` for the body;
901 /// in the case of closures, this will be redirected to the enclosing function.
902 query region_scope_tree(def_id: DefId) -> &'tcx region::ScopeTree {
903 desc { |tcx| "computing drop scopes for `{}`", tcx.def_path_str(def_id) }
906 query mir_shims(key: ty::InstanceDef<'tcx>) -> mir::Body<'tcx> {
907 storage(ArenaCacheSelector<'tcx>)
908 desc { |tcx| "generating MIR shim for `{}`", tcx.def_path_str(key.def_id()) }
911 /// The `symbol_name` query provides the symbol name for calling a
912 /// given instance from the local crate. In particular, it will also
913 /// look up the correct symbol name of instances from upstream crates.
914 query symbol_name(key: ty::Instance<'tcx>) -> ty::SymbolName<'tcx> {
915 desc { "computing the symbol for `{}`", key }
916 cache_on_disk_if { true }
919 query opt_def_kind(def_id: DefId) -> Option<DefKind> {
920 desc { |tcx| "looking up definition kind of `{}`", tcx.def_path_str(def_id) }
923 query def_span(def_id: DefId) -> Span {
924 desc { |tcx| "looking up span for `{}`", tcx.def_path_str(def_id) }
925 // FIXME(mw): DefSpans are not really inputs since they are derived from
926 // HIR. But at the moment HIR hashing still contains some hacks that allow
927 // to make type debuginfo to be source location independent. Declaring
928 // DefSpan an input makes sure that changes to these are always detected
929 // regardless of HIR hashing.
933 query def_ident_span(def_id: DefId) -> Option<Span> {
934 desc { |tcx| "looking up span for `{}`'s identifier", tcx.def_path_str(def_id) }
937 query lookup_stability(def_id: DefId) -> Option<&'tcx attr::Stability> {
938 desc { |tcx| "looking up stability of `{}`", tcx.def_path_str(def_id) }
941 query lookup_const_stability(def_id: DefId) -> Option<&'tcx attr::ConstStability> {
942 desc { |tcx| "looking up const stability of `{}`", tcx.def_path_str(def_id) }
945 query should_inherit_track_caller(def_id: DefId) -> bool {
946 desc { |tcx| "computing should_inherit_track_caller of `{}`", tcx.def_path_str(def_id) }
949 query lookup_deprecation_entry(def_id: DefId) -> Option<DeprecationEntry> {
950 desc { |tcx| "checking whether `{}` is deprecated", tcx.def_path_str(def_id) }
953 query item_attrs(def_id: DefId) -> &'tcx [ast::Attribute] {
954 desc { |tcx| "collecting attributes of `{}`", tcx.def_path_str(def_id) }
957 query codegen_fn_attrs(def_id: DefId) -> CodegenFnAttrs {
958 desc { |tcx| "computing codegen attributes of `{}`", tcx.def_path_str(def_id) }
959 storage(ArenaCacheSelector<'tcx>)
960 cache_on_disk_if { true }
963 query fn_arg_names(def_id: DefId) -> &'tcx [rustc_span::symbol::Ident] {
964 desc { |tcx| "looking up function parameter names for `{}`", tcx.def_path_str(def_id) }
966 /// Gets the rendered value of the specified constant or associated constant.
968 query rendered_const(def_id: DefId) -> String {
969 desc { |tcx| "rendering constant intializer of `{}`", tcx.def_path_str(def_id) }
971 query impl_parent(def_id: DefId) -> Option<DefId> {
972 desc { |tcx| "computing specialization parent impl of `{}`", tcx.def_path_str(def_id) }
975 /// Given an `associated_item`, find the trait it belongs to.
976 /// Return `None` if the `DefId` is not an associated item.
977 query trait_of_item(associated_item: DefId) -> Option<DefId> {
978 desc { |tcx| "finding trait defining `{}`", tcx.def_path_str(associated_item) }
981 query is_ctfe_mir_available(key: DefId) -> bool {
982 desc { |tcx| "checking if item has ctfe mir available: `{}`", tcx.def_path_str(key) }
984 query is_mir_available(key: DefId) -> bool {
985 desc { |tcx| "checking if item has mir available: `{}`", tcx.def_path_str(key) }
988 query vtable_entries(key: ty::PolyTraitRef<'tcx>)
989 -> &'tcx [ty::VtblEntry<'tcx>] {
990 desc { |tcx| "finding all vtable entries for trait {}", tcx.def_path_str(key.def_id()) }
993 query vtable_trait_upcasting_coercion_new_vptr_slot(key: (ty::Ty<'tcx>, ty::Ty<'tcx>)) -> Option<usize> {
994 desc { |tcx| "finding the slot within vtable for trait object {} vtable ptr during trait upcasting coercion from {} vtable",
998 query codegen_fulfill_obligation(
999 key: (ty::ParamEnv<'tcx>, ty::PolyTraitRef<'tcx>)
1000 ) -> Result<ImplSource<'tcx, ()>, ErrorReported> {
1001 cache_on_disk_if { true }
1003 "checking if `{}` fulfills its obligations",
1004 tcx.def_path_str(key.1.def_id())
1008 /// Return all `impl` blocks in the current crate.
1010 /// To allow caching this between crates, you must pass in [`LOCAL_CRATE`] as the crate number.
1011 /// Passing in any other crate will cause an ICE.
1013 /// [`LOCAL_CRATE`]: rustc_hir::def_id::LOCAL_CRATE
1014 query all_local_trait_impls(_: ()) -> &'tcx BTreeMap<DefId, Vec<LocalDefId>> {
1015 desc { "local trait impls" }
1018 /// Given a trait `trait_id`, return all known `impl` blocks.
1019 query trait_impls_of(trait_id: DefId) -> ty::trait_def::TraitImpls {
1020 storage(ArenaCacheSelector<'tcx>)
1021 desc { |tcx| "trait impls of `{}`", tcx.def_path_str(trait_id) }
1024 query specialization_graph_of(trait_id: DefId) -> specialization_graph::Graph {
1025 storage(ArenaCacheSelector<'tcx>)
1026 desc { |tcx| "building specialization graph of trait `{}`", tcx.def_path_str(trait_id) }
1027 cache_on_disk_if { true }
1029 query object_safety_violations(trait_id: DefId) -> &'tcx [traits::ObjectSafetyViolation] {
1030 desc { |tcx| "determine object safety of trait `{}`", tcx.def_path_str(trait_id) }
1033 /// Gets the ParameterEnvironment for a given item; this environment
1034 /// will be in "user-facing" mode, meaning that it is suitable for
1035 /// type-checking etc, and it does not normalize specializable
1036 /// associated types. This is almost always what you want,
1037 /// unless you are doing MIR optimizations, in which case you
1038 /// might want to use `reveal_all()` method to change modes.
1039 query param_env(def_id: DefId) -> ty::ParamEnv<'tcx> {
1040 desc { |tcx| "computing normalized predicates of `{}`", tcx.def_path_str(def_id) }
1043 /// Like `param_env`, but returns the `ParamEnv` in `Reveal::All` mode.
1044 /// Prefer this over `tcx.param_env(def_id).with_reveal_all_normalized(tcx)`,
1045 /// as this method is more efficient.
1046 query param_env_reveal_all_normalized(def_id: DefId) -> ty::ParamEnv<'tcx> {
1047 desc { |tcx| "computing revealed normalized predicates of `{}`", tcx.def_path_str(def_id) }
1050 /// Trait selection queries. These are best used by invoking `ty.is_copy_modulo_regions()`,
1051 /// `ty.is_copy()`, etc, since that will prune the environment where possible.
1052 query is_copy_raw(env: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool {
1053 desc { "computing whether `{}` is `Copy`", env.value }
1055 /// Query backing `TyS::is_sized`.
1056 query is_sized_raw(env: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool {
1057 desc { "computing whether `{}` is `Sized`", env.value }
1059 /// Query backing `TyS::is_freeze`.
1060 query is_freeze_raw(env: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool {
1061 desc { "computing whether `{}` is freeze", env.value }
1063 /// Query backing `TyS::is_unpin`.
1064 query is_unpin_raw(env: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool {
1065 desc { "computing whether `{}` is `Unpin`", env.value }
1067 /// Query backing `TyS::needs_drop`.
1068 query needs_drop_raw(env: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool {
1069 desc { "computing whether `{}` needs drop", env.value }
1071 /// Query backing `TyS::has_significant_drop_raw`.
1072 query has_significant_drop_raw(env: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool {
1073 desc { "computing whether `{}` has a significant drop", env.value }
1076 /// Query backing `TyS::is_structural_eq_shallow`.
1078 /// This is only correct for ADTs. Call `is_structural_eq_shallow` to handle all types
1080 query has_structural_eq_impls(ty: Ty<'tcx>) -> bool {
1082 "computing whether `{:?}` implements `PartialStructuralEq` and `StructuralEq`",
1087 /// A list of types where the ADT requires drop if and only if any of
1088 /// those types require drop. If the ADT is known to always need drop
1089 /// then `Err(AlwaysRequiresDrop)` is returned.
1090 query adt_drop_tys(def_id: DefId) -> Result<&'tcx ty::List<Ty<'tcx>>, AlwaysRequiresDrop> {
1091 desc { |tcx| "computing when `{}` needs drop", tcx.def_path_str(def_id) }
1092 cache_on_disk_if { true }
1095 /// A list of types where the ADT requires drop if and only if any of those types
1096 /// has significant drop. A type marked with the attribute `rustc_insignificant_dtor`
1097 /// is considered to not be significant. A drop is significant if it is implemented
1098 /// by the user or does anything that will have any observable behavior (other than
1099 /// freeing up memory). If the ADT is known to have a significant destructor then
1100 /// `Err(AlwaysRequiresDrop)` is returned.
1101 query adt_significant_drop_tys(def_id: DefId) -> Result<&'tcx ty::List<Ty<'tcx>>, AlwaysRequiresDrop> {
1102 desc { |tcx| "computing when `{}` has a significant destructor", tcx.def_path_str(def_id) }
1103 cache_on_disk_if { false }
1106 /// Computes the layout of a type. Note that this implicitly
1107 /// executes in "reveal all" mode, and will normalize the input type.
1109 key: ty::ParamEnvAnd<'tcx, Ty<'tcx>>
1110 ) -> Result<ty::layout::TyAndLayout<'tcx>, ty::layout::LayoutError<'tcx>> {
1111 desc { "computing layout of `{}`", key.value }
1114 query dylib_dependency_formats(_: CrateNum)
1115 -> &'tcx [(CrateNum, LinkagePreference)] {
1116 desc { "dylib dependency formats of crate" }
1119 query dependency_formats(_: ()) -> Lrc<crate::middle::dependency_format::Dependencies> {
1120 desc { "get the linkage format of all dependencies" }
1123 query is_compiler_builtins(_: CrateNum) -> bool {
1125 desc { "checking if the crate is_compiler_builtins" }
1127 query has_global_allocator(_: CrateNum) -> bool {
1128 // This query depends on untracked global state in CStore
1131 desc { "checking if the crate has_global_allocator" }
1133 query has_panic_handler(_: CrateNum) -> bool {
1135 desc { "checking if the crate has_panic_handler" }
1137 query is_profiler_runtime(_: CrateNum) -> bool {
1139 desc { "query a crate is `#![profiler_runtime]`" }
1141 query panic_strategy(_: CrateNum) -> PanicStrategy {
1143 desc { "query a crate's configured panic strategy" }
1145 query is_no_builtins(_: CrateNum) -> bool {
1147 desc { "test whether a crate has `#![no_builtins]`" }
1149 query symbol_mangling_version(_: CrateNum) -> SymbolManglingVersion {
1151 desc { "query a crate's symbol mangling version" }
1154 query extern_crate(def_id: DefId) -> Option<&'tcx ExternCrate> {
1156 desc { "getting crate's ExternCrateData" }
1159 query specializes(_: (DefId, DefId)) -> bool {
1160 desc { "computing whether impls specialize one another" }
1162 query in_scope_traits_map(_: LocalDefId)
1163 -> Option<&'tcx FxHashMap<ItemLocalId, Box<[TraitCandidate]>>> {
1164 desc { "traits in scope at a block" }
1167 query module_exports(def_id: LocalDefId) -> Option<&'tcx [Export<LocalDefId>]> {
1168 desc { |tcx| "looking up items exported by `{}`", tcx.def_path_str(def_id.to_def_id()) }
1171 query impl_defaultness(def_id: DefId) -> hir::Defaultness {
1172 desc { |tcx| "looking up whether `{}` is a default impl", tcx.def_path_str(def_id) }
1175 query impl_constness(def_id: DefId) -> hir::Constness {
1176 desc { |tcx| "looking up whether `{}` is a const impl", tcx.def_path_str(def_id) }
1179 query check_item_well_formed(key: LocalDefId) -> () {
1180 desc { |tcx| "checking that `{}` is well-formed", tcx.def_path_str(key.to_def_id()) }
1182 query check_trait_item_well_formed(key: LocalDefId) -> () {
1183 desc { |tcx| "checking that `{}` is well-formed", tcx.def_path_str(key.to_def_id()) }
1185 query check_impl_item_well_formed(key: LocalDefId) -> () {
1186 desc { |tcx| "checking that `{}` is well-formed", tcx.def_path_str(key.to_def_id()) }
1189 // The `DefId`s of all non-generic functions and statics in the given crate
1190 // that can be reached from outside the crate.
1192 // We expect this items to be available for being linked to.
1194 // This query can also be called for `LOCAL_CRATE`. In this case it will
1195 // compute which items will be reachable to other crates, taking into account
1196 // the kind of crate that is currently compiled. Crates with only a
1197 // C interface have fewer reachable things.
1199 // Does not include external symbols that don't have a corresponding DefId,
1200 // like the compiler-generated `main` function and so on.
1201 query reachable_non_generics(_: CrateNum)
1202 -> DefIdMap<SymbolExportLevel> {
1203 storage(ArenaCacheSelector<'tcx>)
1204 desc { "looking up the exported symbols of a crate" }
1206 query is_reachable_non_generic(def_id: DefId) -> bool {
1207 desc { |tcx| "checking whether `{}` is an exported symbol", tcx.def_path_str(def_id) }
1209 query is_unreachable_local_definition(def_id: LocalDefId) -> bool {
1211 "checking whether `{}` is reachable from outside the crate",
1212 tcx.def_path_str(def_id.to_def_id()),
1216 /// The entire set of monomorphizations the local crate can safely link
1217 /// to because they are exported from upstream crates. Do not depend on
1218 /// this directly, as its value changes anytime a monomorphization gets
1219 /// added or removed in any upstream crate. Instead use the narrower
1220 /// `upstream_monomorphizations_for`, `upstream_drop_glue_for`, or, even
1221 /// better, `Instance::upstream_monomorphization()`.
1222 query upstream_monomorphizations(_: ()) -> DefIdMap<FxHashMap<SubstsRef<'tcx>, CrateNum>> {
1223 storage(ArenaCacheSelector<'tcx>)
1224 desc { "collecting available upstream monomorphizations" }
1227 /// Returns the set of upstream monomorphizations available for the
1228 /// generic function identified by the given `def_id`. The query makes
1229 /// sure to make a stable selection if the same monomorphization is
1230 /// available in multiple upstream crates.
1232 /// You likely want to call `Instance::upstream_monomorphization()`
1233 /// instead of invoking this query directly.
1234 query upstream_monomorphizations_for(def_id: DefId)
1235 -> Option<&'tcx FxHashMap<SubstsRef<'tcx>, CrateNum>> {
1237 "collecting available upstream monomorphizations for `{}`",
1238 tcx.def_path_str(def_id),
1242 /// Returns the upstream crate that exports drop-glue for the given
1243 /// type (`substs` is expected to be a single-item list containing the
1244 /// type one wants drop-glue for).
1246 /// This is a subset of `upstream_monomorphizations_for` in order to
1247 /// increase dep-tracking granularity. Otherwise adding or removing any
1248 /// type with drop-glue in any upstream crate would invalidate all
1249 /// functions calling drop-glue of an upstream type.
1251 /// You likely want to call `Instance::upstream_monomorphization()`
1252 /// instead of invoking this query directly.
1254 /// NOTE: This query could easily be extended to also support other
1255 /// common functions that have are large set of monomorphizations
1256 /// (like `Clone::clone` for example).
1257 query upstream_drop_glue_for(substs: SubstsRef<'tcx>) -> Option<CrateNum> {
1258 desc { "available upstream drop-glue for `{:?}`", substs }
1261 query foreign_modules(_: CrateNum) -> Lrc<FxHashMap<DefId, ForeignModule>> {
1262 desc { "looking up the foreign modules of a linked crate" }
1265 /// Identifies the entry-point (e.g., the `main` function) for a given
1266 /// crate, returning `None` if there is no entry point (such as for library crates).
1267 query entry_fn(_: ()) -> Option<(DefId, EntryFnType)> {
1268 desc { "looking up the entry function of a crate" }
1270 query proc_macro_decls_static(_: ()) -> Option<LocalDefId> {
1271 desc { "looking up the derive registrar for a crate" }
1273 // The macro which defines `rustc_metadata::provide_extern` depends on this query's name.
1274 // Changing the name should cause a compiler error, but in case that changes, be aware.
1275 query crate_hash(_: CrateNum) -> Svh {
1277 desc { "looking up the hash a crate" }
1279 query crate_host_hash(_: CrateNum) -> Option<Svh> {
1281 desc { "looking up the hash of a host version of a crate" }
1283 query extra_filename(_: CrateNum) -> String {
1285 desc { "looking up the extra filename for a crate" }
1287 query crate_extern_paths(_: CrateNum) -> Vec<PathBuf> {
1289 desc { "looking up the paths for extern crates" }
1292 /// Given a crate and a trait, look up all impls of that trait in the crate.
1293 /// Return `(impl_id, self_ty)`.
1294 query implementations_of_trait(_: (CrateNum, DefId))
1295 -> &'tcx [(DefId, Option<ty::fast_reject::SimplifiedType>)] {
1296 desc { "looking up implementations of a trait in a crate" }
1299 /// Given a crate, look up all trait impls in that crate.
1300 /// Return `(impl_id, self_ty)`.
1301 query all_trait_implementations(_: CrateNum)
1302 -> &'tcx [(DefId, Option<ty::fast_reject::SimplifiedType>)] {
1303 desc { "looking up all (?) trait implementations" }
1306 query is_dllimport_foreign_item(def_id: DefId) -> bool {
1307 desc { |tcx| "is_dllimport_foreign_item({})", tcx.def_path_str(def_id) }
1309 query is_statically_included_foreign_item(def_id: DefId) -> bool {
1310 desc { |tcx| "is_statically_included_foreign_item({})", tcx.def_path_str(def_id) }
1312 query native_library_kind(def_id: DefId)
1313 -> Option<NativeLibKind> {
1314 desc { |tcx| "native_library_kind({})", tcx.def_path_str(def_id) }
1317 /// Does lifetime resolution, but does not descend into trait items. This
1318 /// should only be used for resolving lifetimes of on trait definitions,
1319 /// and is used to avoid cycles. Importantly, `resolve_lifetimes` still visits
1320 /// the same lifetimes and is responsible for diagnostics.
1321 /// See `rustc_resolve::late::lifetimes for details.
1322 query resolve_lifetimes_trait_definition(_: LocalDefId) -> ResolveLifetimes {
1323 storage(ArenaCacheSelector<'tcx>)
1324 desc { "resolving lifetimes for a trait definition" }
1326 /// Does lifetime resolution on items. Importantly, we can't resolve
1327 /// lifetimes directly on things like trait methods, because of trait params.
1328 /// See `rustc_resolve::late::lifetimes for details.
1329 query resolve_lifetimes(_: LocalDefId) -> ResolveLifetimes {
1330 storage(ArenaCacheSelector<'tcx>)
1331 desc { "resolving lifetimes" }
1333 query named_region_map(_: LocalDefId) ->
1334 Option<&'tcx FxHashMap<ItemLocalId, Region>> {
1335 desc { "looking up a named region" }
1337 query is_late_bound_map(_: LocalDefId) ->
1338 Option<(LocalDefId, &'tcx FxHashSet<ItemLocalId>)> {
1339 desc { "testing if a region is late bound" }
1341 /// For a given item (like a struct), gets the default lifetimes to be used
1342 /// for each parameter if a trait object were to be passed for that parameter.
1343 /// For example, for `struct Foo<'a, T, U>`, this would be `['static, 'static]`.
1344 /// For `struct Foo<'a, T: 'a, U>`, this would instead be `['a, 'static]`.
1345 query object_lifetime_defaults_map(_: LocalDefId)
1346 -> Option<Vec<ObjectLifetimeDefault>> {
1347 desc { "looking up lifetime defaults for a region on an item" }
1349 query late_bound_vars_map(_: LocalDefId)
1350 -> Option<&'tcx FxHashMap<ItemLocalId, Vec<ty::BoundVariableKind>>> {
1351 desc { "looking up late bound vars" }
1354 query lifetime_scope_map(_: LocalDefId) -> Option<FxHashMap<ItemLocalId, LifetimeScopeForPath>> {
1355 desc { "finds the lifetime scope for an HirId of a PathSegment" }
1358 query visibility(def_id: DefId) -> ty::Visibility {
1359 desc { |tcx| "computing visibility of `{}`", tcx.def_path_str(def_id) }
1362 /// Computes the set of modules from which this type is visibly uninhabited.
1363 /// To check whether a type is uninhabited at all (not just from a given module), you could
1364 /// check whether the forest is empty.
1365 query type_uninhabited_from(
1366 key: ty::ParamEnvAnd<'tcx, Ty<'tcx>>
1367 ) -> ty::inhabitedness::DefIdForest {
1368 desc { "computing the inhabitedness of `{:?}`", key }
1371 query dep_kind(_: CrateNum) -> CrateDepKind {
1373 desc { "fetching what a dependency looks like" }
1375 query crate_name(_: CrateNum) -> Symbol {
1377 desc { "fetching what a crate is named" }
1379 query item_children(def_id: DefId) -> &'tcx [Export<hir::HirId>] {
1380 desc { |tcx| "collecting child items of `{}`", tcx.def_path_str(def_id) }
1382 query extern_mod_stmt_cnum(def_id: LocalDefId) -> Option<CrateNum> {
1383 desc { |tcx| "computing crate imported by `{}`", tcx.def_path_str(def_id.to_def_id()) }
1386 query get_lib_features(_: ()) -> LibFeatures {
1387 storage(ArenaCacheSelector<'tcx>)
1389 desc { "calculating the lib features map" }
1391 query defined_lib_features(_: CrateNum)
1392 -> &'tcx [(Symbol, Option<Symbol>)] {
1393 desc { "calculating the lib features defined in a crate" }
1395 /// Returns the lang items defined in another crate by loading it from metadata.
1396 query get_lang_items(_: ()) -> LanguageItems {
1397 storage(ArenaCacheSelector<'tcx>)
1399 desc { "calculating the lang items map" }
1402 /// Returns all diagnostic items defined in all crates.
1403 query all_diagnostic_items(_: ()) -> FxHashMap<Symbol, DefId> {
1404 storage(ArenaCacheSelector<'tcx>)
1406 desc { "calculating the diagnostic items map" }
1409 /// Returns the lang items defined in another crate by loading it from metadata.
1410 query defined_lang_items(_: CrateNum) -> &'tcx [(DefId, usize)] {
1411 desc { "calculating the lang items defined in a crate" }
1414 /// Returns the diagnostic items defined in a crate.
1415 query diagnostic_items(_: CrateNum) -> FxHashMap<Symbol, DefId> {
1416 storage(ArenaCacheSelector<'tcx>)
1417 desc { "calculating the diagnostic items map in a crate" }
1420 query missing_lang_items(_: CrateNum) -> &'tcx [LangItem] {
1421 desc { "calculating the missing lang items in a crate" }
1423 query visible_parent_map(_: ()) -> DefIdMap<DefId> {
1424 storage(ArenaCacheSelector<'tcx>)
1425 desc { "calculating the visible parent map" }
1427 query trimmed_def_paths(_: ()) -> FxHashMap<DefId, Symbol> {
1428 storage(ArenaCacheSelector<'tcx>)
1429 desc { "calculating trimmed def paths" }
1431 query missing_extern_crate_item(_: CrateNum) -> bool {
1433 desc { "seeing if we're missing an `extern crate` item for this crate" }
1435 query used_crate_source(_: CrateNum) -> Lrc<CrateSource> {
1437 desc { "looking at the source for a crate" }
1439 query postorder_cnums(_: ()) -> &'tcx [CrateNum] {
1441 desc { "generating a postorder list of CrateNums" }
1443 /// Returns whether or not the crate with CrateNum 'cnum'
1444 /// is marked as a private dependency
1445 query is_private_dep(c: CrateNum) -> bool {
1447 desc { "check whether crate {} is a private dependency", c }
1449 query allocator_kind(_: ()) -> Option<AllocatorKind> {
1451 desc { "allocator kind for the current crate" }
1454 query upvars_mentioned(def_id: DefId) -> Option<&'tcx FxIndexMap<hir::HirId, hir::Upvar>> {
1455 desc { |tcx| "collecting upvars mentioned in `{}`", tcx.def_path_str(def_id) }
1458 query maybe_unused_trait_import(def_id: LocalDefId) -> bool {
1459 desc { |tcx| "maybe_unused_trait_import for `{}`", tcx.def_path_str(def_id.to_def_id()) }
1461 query maybe_unused_extern_crates(_: ()) -> &'tcx [(LocalDefId, Span)] {
1462 desc { "looking up all possibly unused extern crates" }
1464 query names_imported_by_glob_use(def_id: LocalDefId) -> &'tcx FxHashSet<Symbol> {
1465 desc { |tcx| "names_imported_by_glob_use for `{}`", tcx.def_path_str(def_id.to_def_id()) }
1468 query stability_index(_: ()) -> stability::Index<'tcx> {
1469 storage(ArenaCacheSelector<'tcx>)
1471 desc { "calculating the stability index for the local crate" }
1473 query crates(_: ()) -> &'tcx [CrateNum] {
1475 desc { "fetching all foreign CrateNum instances" }
1478 /// A vector of every trait accessible in the whole crate
1479 /// (i.e., including those from subcrates). This is used only for
1480 /// error reporting.
1481 query all_traits(_: ()) -> &'tcx [DefId] {
1482 desc { "fetching all foreign and local traits" }
1485 /// The list of symbols exported from the given crate.
1487 /// - All names contained in `exported_symbols(cnum)` are guaranteed to
1488 /// correspond to a publicly visible symbol in `cnum` machine code.
1489 /// - The `exported_symbols` sets of different crates do not intersect.
1490 query exported_symbols(_: CrateNum)
1491 -> &'tcx [(ExportedSymbol<'tcx>, SymbolExportLevel)] {
1492 desc { "exported_symbols" }
1495 query collect_and_partition_mono_items(_: ()) -> (&'tcx DefIdSet, &'tcx [CodegenUnit<'tcx>]) {
1497 desc { "collect_and_partition_mono_items" }
1499 query is_codegened_item(def_id: DefId) -> bool {
1500 desc { |tcx| "determining whether `{}` needs codegen", tcx.def_path_str(def_id) }
1503 /// All items participating in code generation together with items inlined into them.
1504 query codegened_and_inlined_items(_: ()) -> &'tcx DefIdSet {
1506 desc { "codegened_and_inlined_items" }
1509 query codegen_unit(_: Symbol) -> &'tcx CodegenUnit<'tcx> {
1510 desc { "codegen_unit" }
1512 query unused_generic_params(key: DefId) -> FiniteBitSet<u32> {
1513 cache_on_disk_if { key.is_local() }
1515 |tcx| "determining which generic parameters are unused by `{}`",
1516 tcx.def_path_str(key)
1519 query backend_optimization_level(_: ()) -> OptLevel {
1520 desc { "optimization level used by backend" }
1523 query output_filenames(_: ()) -> Arc<OutputFilenames> {
1525 desc { "output_filenames" }
1528 /// Do not call this query directly: invoke `normalize` instead.
1529 query normalize_projection_ty(
1530 goal: CanonicalProjectionGoal<'tcx>
1532 &'tcx Canonical<'tcx, canonical::QueryResponse<'tcx, NormalizationResult<'tcx>>>,
1535 desc { "normalizing `{:?}`", goal }
1538 /// Do not call this query directly: invoke `normalize_erasing_regions` instead.
1539 query normalize_generic_arg_after_erasing_regions(
1540 goal: ParamEnvAnd<'tcx, GenericArg<'tcx>>
1541 ) -> GenericArg<'tcx> {
1542 desc { "normalizing `{}`", goal.value }
1545 /// Do not call this query directly: invoke `normalize_erasing_regions` instead.
1546 query normalize_mir_const_after_erasing_regions(
1547 goal: ParamEnvAnd<'tcx, mir::ConstantKind<'tcx>>
1548 ) -> mir::ConstantKind<'tcx> {
1549 desc { "normalizing `{}`", goal.value }
1552 query implied_outlives_bounds(
1553 goal: CanonicalTyGoal<'tcx>
1555 &'tcx Canonical<'tcx, canonical::QueryResponse<'tcx, Vec<OutlivesBound<'tcx>>>>,
1558 desc { "computing implied outlives bounds for `{:?}`", goal }
1561 /// Do not call this query directly: invoke `infcx.at().dropck_outlives()` instead.
1562 query dropck_outlives(
1563 goal: CanonicalTyGoal<'tcx>
1565 &'tcx Canonical<'tcx, canonical::QueryResponse<'tcx, DropckOutlivesResult<'tcx>>>,
1568 desc { "computing dropck types for `{:?}`", goal }
1571 /// Do not call this query directly: invoke `infcx.predicate_may_hold()` or
1572 /// `infcx.predicate_must_hold()` instead.
1573 query evaluate_obligation(
1574 goal: CanonicalPredicateGoal<'tcx>
1575 ) -> Result<traits::EvaluationResult, traits::OverflowError> {
1576 desc { "evaluating trait selection obligation `{}`", goal.value.value }
1579 query evaluate_goal(
1580 goal: traits::CanonicalChalkEnvironmentAndGoal<'tcx>
1582 &'tcx Canonical<'tcx, canonical::QueryResponse<'tcx, ()>>,
1585 desc { "evaluating trait selection obligation `{}`", goal.value }
1588 /// Do not call this query directly: part of the `Eq` type-op
1589 query type_op_ascribe_user_type(
1590 goal: CanonicalTypeOpAscribeUserTypeGoal<'tcx>
1592 &'tcx Canonical<'tcx, canonical::QueryResponse<'tcx, ()>>,
1595 desc { "evaluating `type_op_ascribe_user_type` `{:?}`", goal }
1598 /// Do not call this query directly: part of the `Eq` type-op
1600 goal: CanonicalTypeOpEqGoal<'tcx>
1602 &'tcx Canonical<'tcx, canonical::QueryResponse<'tcx, ()>>,
1605 desc { "evaluating `type_op_eq` `{:?}`", goal }
1608 /// Do not call this query directly: part of the `Subtype` type-op
1609 query type_op_subtype(
1610 goal: CanonicalTypeOpSubtypeGoal<'tcx>
1612 &'tcx Canonical<'tcx, canonical::QueryResponse<'tcx, ()>>,
1615 desc { "evaluating `type_op_subtype` `{:?}`", goal }
1618 /// Do not call this query directly: part of the `ProvePredicate` type-op
1619 query type_op_prove_predicate(
1620 goal: CanonicalTypeOpProvePredicateGoal<'tcx>
1622 &'tcx Canonical<'tcx, canonical::QueryResponse<'tcx, ()>>,
1625 desc { "evaluating `type_op_prove_predicate` `{:?}`", goal }
1628 /// Do not call this query directly: part of the `Normalize` type-op
1629 query type_op_normalize_ty(
1630 goal: CanonicalTypeOpNormalizeGoal<'tcx, Ty<'tcx>>
1632 &'tcx Canonical<'tcx, canonical::QueryResponse<'tcx, Ty<'tcx>>>,
1635 desc { "normalizing `{:?}`", goal }
1638 /// Do not call this query directly: part of the `Normalize` type-op
1639 query type_op_normalize_predicate(
1640 goal: CanonicalTypeOpNormalizeGoal<'tcx, ty::Predicate<'tcx>>
1642 &'tcx Canonical<'tcx, canonical::QueryResponse<'tcx, ty::Predicate<'tcx>>>,
1645 desc { "normalizing `{:?}`", goal }
1648 /// Do not call this query directly: part of the `Normalize` type-op
1649 query type_op_normalize_poly_fn_sig(
1650 goal: CanonicalTypeOpNormalizeGoal<'tcx, ty::PolyFnSig<'tcx>>
1652 &'tcx Canonical<'tcx, canonical::QueryResponse<'tcx, ty::PolyFnSig<'tcx>>>,
1655 desc { "normalizing `{:?}`", goal }
1658 /// Do not call this query directly: part of the `Normalize` type-op
1659 query type_op_normalize_fn_sig(
1660 goal: CanonicalTypeOpNormalizeGoal<'tcx, ty::FnSig<'tcx>>
1662 &'tcx Canonical<'tcx, canonical::QueryResponse<'tcx, ty::FnSig<'tcx>>>,
1665 desc { "normalizing `{:?}`", goal }
1668 query subst_and_check_impossible_predicates(key: (DefId, SubstsRef<'tcx>)) -> bool {
1670 "impossible substituted predicates:`{}`",
1671 tcx.def_path_str(key.0)
1675 query method_autoderef_steps(
1676 goal: CanonicalTyGoal<'tcx>
1677 ) -> MethodAutoderefStepsResult<'tcx> {
1678 desc { "computing autoderef types for `{:?}`", goal }
1681 query supported_target_features(_: CrateNum) -> FxHashMap<String, Option<Symbol>> {
1682 storage(ArenaCacheSelector<'tcx>)
1684 desc { "looking up supported target features" }
1687 /// Get an estimate of the size of an InstanceDef based on its MIR for CGU partitioning.
1688 query instance_def_size_estimate(def: ty::InstanceDef<'tcx>)
1690 desc { |tcx| "estimating size for `{}`", tcx.def_path_str(def.def_id()) }
1693 query features_query(_: ()) -> &'tcx rustc_feature::Features {
1695 desc { "looking up enabled feature gates" }
1698 /// Attempt to resolve the given `DefId` to an `Instance`, for the
1699 /// given generics args (`SubstsRef`), returning one of:
1700 /// * `Ok(Some(instance))` on success
1701 /// * `Ok(None)` when the `SubstsRef` are still too generic,
1702 /// and therefore don't allow finding the final `Instance`
1703 /// * `Err(ErrorReported)` when the `Instance` resolution process
1704 /// couldn't complete due to errors elsewhere - this is distinct
1705 /// from `Ok(None)` to avoid misleading diagnostics when an error
1706 /// has already been/will be emitted, for the original cause
1707 query resolve_instance(
1708 key: ty::ParamEnvAnd<'tcx, (DefId, SubstsRef<'tcx>)>
1709 ) -> Result<Option<ty::Instance<'tcx>>, ErrorReported> {
1710 desc { "resolving instance `{}`", ty::Instance::new(key.value.0, key.value.1) }
1713 query resolve_instance_of_const_arg(
1714 key: ty::ParamEnvAnd<'tcx, (LocalDefId, DefId, SubstsRef<'tcx>)>
1715 ) -> Result<Option<ty::Instance<'tcx>>, ErrorReported> {
1717 "resolving instance of the const argument `{}`",
1718 ty::Instance::new(key.value.0.to_def_id(), key.value.2),
1722 query normalize_opaque_types(key: &'tcx ty::List<ty::Predicate<'tcx>>) -> &'tcx ty::List<ty::Predicate<'tcx>> {
1723 desc { "normalizing opaque types in {:?}", key }
1726 /// Checks whether a type is definitely uninhabited. This is
1727 /// conservative: for some types that are uninhabited we return `false`,
1728 /// but we only return `true` for types that are definitely uninhabited.
1729 /// `ty.conservative_is_privately_uninhabited` implies that any value of type `ty`
1730 /// will be `Abi::Uninhabited`. (Note that uninhabited types may have nonzero
1731 /// size, to account for partial initialisation. See #49298 for details.)
1732 query conservative_is_privately_uninhabited(key: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool {
1733 desc { "conservatively checking if {:?} is privately uninhabited", key }
1736 query limits(key: ()) -> Limits {
1737 desc { "looking up limits" }
1740 /// Performs an HIR-based well-formed check on the item with the given `HirId`. If
1741 /// we get an `Unimplemented` error that matches the provided `Predicate`, return
1742 /// the cause of the newly created obligation.
1744 /// This is only used by error-reporting code to get a better cause (in particular, a better
1745 /// span) for an *existing* error. Therefore, it is best-effort, and may never handle
1746 /// all of the cases that the normal `ty::Ty`-based wfcheck does. This is fine,
1747 /// because the `ty::Ty`-based wfcheck is always run.
1748 query diagnostic_hir_wf_check(key: (ty::Predicate<'tcx>, traits::WellFormedLoc)) -> Option<traits::ObligationCause<'tcx>> {
1751 desc { "performing HIR wf-checking for predicate {:?} at item {:?}", key.0, key.1 }