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Commit | Line | Data |
---|---|---|
ba9703b0 | 1 | use rustc_data_structures::fx::FxHashSet; |
1b1a35ee | 2 | use rustc_errors::{Applicability, ErrorReported, StashKey}; |
74b04a01 XL |
3 | use rustc_hir as hir; |
4 | use rustc_hir::def::{DefKind, Res}; | |
f9f354fc | 5 | use rustc_hir::def_id::{DefId, LocalDefId}; |
74b04a01 XL |
6 | use rustc_hir::intravisit; |
7 | use rustc_hir::intravisit::Visitor; | |
5869c6ff | 8 | use rustc_hir::{HirId, Node}; |
ba9703b0 | 9 | use rustc_middle::hir::map::Map; |
94222f64 | 10 | use rustc_middle::ty::subst::{GenericArgKind, InternalSubsts, SubstsRef}; |
ba9703b0 | 11 | use rustc_middle::ty::util::IntTypeExt; |
136023e0 | 12 | use rustc_middle::ty::{self, DefIdTree, Ty, TyCtxt, TypeFoldable, TypeFolder}; |
f035d41b | 13 | use rustc_span::symbol::Ident; |
74b04a01 XL |
14 | use rustc_span::{Span, DUMMY_SP}; |
15 | ||
16 | use super::ItemCtxt; | |
17 | use super::{bad_placeholder_type, is_suggestable_infer_ty}; | |
18 | ||
3dfed10e XL |
19 | /// Computes the relevant generic parameter for a potential generic const argument. |
20 | /// | |
21 | /// This should be called using the query `tcx.opt_const_param_of`. | |
22 | pub(super) fn opt_const_param_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> Option<DefId> { | |
94222f64 XL |
23 | // FIXME(generic_arg_infer): allow for returning DefIds of inference of |
24 | // GenericArg::Infer below. This may require a change where GenericArg::Infer has some flag | |
25 | // for const or type. | |
3dfed10e | 26 | use hir::*; |
3dfed10e XL |
27 | let hir_id = tcx.hir().local_def_id_to_hir_id(def_id); |
28 | ||
29 | if let Node::AnonConst(_) = tcx.hir().get(hir_id) { | |
30 | let parent_node_id = tcx.hir().get_parent_node(hir_id); | |
31 | let parent_node = tcx.hir().get(parent_node_id); | |
32 | ||
33 | match parent_node { | |
6a06907d XL |
34 | // This match arm is for when the def_id appears in a GAT whose |
35 | // path can't be resolved without typechecking e.g. | |
36 | // | |
37 | // trait Foo { | |
38 | // type Assoc<const N: usize>; | |
39 | // fn foo() -> Self::Assoc<3>; | |
40 | // } | |
41 | // | |
42 | // In the above code we would call this query with the def_id of 3 and | |
43 | // the parent_node we match on would be the hir node for Self::Assoc<3> | |
44 | // | |
45 | // `Self::Assoc<3>` cant be resolved without typchecking here as we | |
46 | // didnt write <Self as Foo>::Assoc<3>. If we did then another match | |
47 | // arm would handle this. | |
48 | // | |
49 | // I believe this match arm is only needed for GAT but I am not 100% sure - BoxyUwU | |
50 | Node::Ty(hir_ty @ Ty { kind: TyKind::Path(QPath::TypeRelative(_, segment)), .. }) => { | |
51 | // Find the Item containing the associated type so we can create an ItemCtxt. | |
52 | // Using the ItemCtxt convert the HIR for the unresolved assoc type into a | |
53 | // ty which is a fully resolved projection. | |
54 | // For the code example above, this would mean converting Self::Assoc<3> | |
55 | // into a ty::Projection(<Self as Foo>::Assoc<3>) | |
56 | let item_hir_id = tcx | |
57 | .hir() | |
58 | .parent_iter(hir_id) | |
59 | .filter(|(_, node)| matches!(node, Node::Item(_))) | |
60 | .map(|(id, _)| id) | |
61 | .next() | |
62 | .unwrap(); | |
63 | let item_did = tcx.hir().local_def_id(item_hir_id).to_def_id(); | |
64 | let item_ctxt = &ItemCtxt::new(tcx, item_did) as &dyn crate::astconv::AstConv<'_>; | |
65 | let ty = item_ctxt.ast_ty_to_ty(hir_ty); | |
66 | ||
67 | // Iterate through the generics of the projection to find the one that corresponds to | |
68 | // the def_id that this query was called with. We filter to only const args here as a | |
69 | // precaution for if it's ever allowed to elide lifetimes in GAT's. It currently isn't | |
70 | // but it can't hurt to be safe ^^ | |
71 | if let ty::Projection(projection) = ty.kind() { | |
72 | let generics = tcx.generics_of(projection.item_def_id); | |
73 | ||
74 | let arg_index = segment | |
75 | .args | |
76 | .and_then(|args| { | |
77 | args.args | |
78 | .iter() | |
79 | .filter(|arg| arg.is_const()) | |
80 | .position(|arg| arg.id() == hir_id) | |
81 | }) | |
82 | .unwrap_or_else(|| { | |
83 | bug!("no arg matching AnonConst in segment"); | |
84 | }); | |
85 | ||
86 | return generics | |
87 | .params | |
88 | .iter() | |
cdc7bbd5 | 89 | .filter(|param| matches!(param.kind, ty::GenericParamDefKind::Const { .. })) |
6a06907d XL |
90 | .nth(arg_index) |
91 | .map(|param| param.def_id); | |
92 | } | |
93 | ||
94 | // I dont think it's possible to reach this but I'm not 100% sure - BoxyUwU | |
95 | tcx.sess.delay_span_bug( | |
96 | tcx.def_span(def_id), | |
97 | "unexpected non-GAT usage of an anon const", | |
98 | ); | |
99 | return None; | |
100 | } | |
3dfed10e XL |
101 | Node::Expr(&Expr { |
102 | kind: | |
103 | ExprKind::MethodCall(segment, ..) | ExprKind::Path(QPath::TypeRelative(_, segment)), | |
104 | .. | |
105 | }) => { | |
106 | let body_owner = tcx.hir().local_def_id(tcx.hir().enclosing_body_owner(hir_id)); | |
107 | let tables = tcx.typeck(body_owner); | |
108 | // This may fail in case the method/path does not actually exist. | |
109 | // As there is no relevant param for `def_id`, we simply return | |
110 | // `None` here. | |
111 | let type_dependent_def = tables.type_dependent_def_id(parent_node_id)?; | |
112 | let idx = segment | |
113 | .args | |
114 | .and_then(|args| { | |
115 | args.args | |
116 | .iter() | |
117 | .filter(|arg| arg.is_const()) | |
118 | .position(|arg| arg.id() == hir_id) | |
119 | }) | |
120 | .unwrap_or_else(|| { | |
121 | bug!("no arg matching AnonConst in segment"); | |
122 | }); | |
123 | ||
124 | tcx.generics_of(type_dependent_def) | |
125 | .params | |
126 | .iter() | |
cdc7bbd5 | 127 | .filter(|param| matches!(param.kind, ty::GenericParamDefKind::Const { .. })) |
3dfed10e XL |
128 | .nth(idx) |
129 | .map(|param| param.def_id) | |
130 | } | |
131 | ||
132 | Node::Ty(&Ty { kind: TyKind::Path(_), .. }) | |
5869c6ff XL |
133 | | Node::Expr(&Expr { kind: ExprKind::Path(_) | ExprKind::Struct(..), .. }) |
134 | | Node::TraitRef(..) | |
135 | | Node::Pat(_) => { | |
3dfed10e XL |
136 | let path = match parent_node { |
137 | Node::Ty(&Ty { kind: TyKind::Path(QPath::Resolved(_, path)), .. }) | |
138 | | Node::TraitRef(&TraitRef { path, .. }) => &*path, | |
139 | Node::Expr(&Expr { | |
140 | kind: | |
141 | ExprKind::Path(QPath::Resolved(_, path)) | |
142 | | ExprKind::Struct(&QPath::Resolved(_, path), ..), | |
143 | .. | |
144 | }) => { | |
145 | let body_owner = | |
146 | tcx.hir().local_def_id(tcx.hir().enclosing_body_owner(hir_id)); | |
147 | let _tables = tcx.typeck(body_owner); | |
148 | &*path | |
149 | } | |
5869c6ff XL |
150 | Node::Pat(pat) => { |
151 | if let Some(path) = get_path_containing_arg_in_pat(pat, hir_id) { | |
152 | path | |
153 | } else { | |
154 | tcx.sess.delay_span_bug( | |
155 | tcx.def_span(def_id), | |
156 | &format!( | |
157 | "unable to find const parent for {} in pat {:?}", | |
158 | hir_id, pat | |
159 | ), | |
160 | ); | |
161 | return None; | |
162 | } | |
163 | } | |
1b1a35ee XL |
164 | _ => { |
165 | tcx.sess.delay_span_bug( | |
166 | tcx.def_span(def_id), | |
167 | &format!("unexpected const parent path {:?}", parent_node), | |
168 | ); | |
169 | return None; | |
170 | } | |
3dfed10e XL |
171 | }; |
172 | ||
173 | // We've encountered an `AnonConst` in some path, so we need to | |
174 | // figure out which generic parameter it corresponds to and return | |
175 | // the relevant type. | |
3dfed10e XL |
176 | let (arg_index, segment) = path |
177 | .segments | |
178 | .iter() | |
179 | .filter_map(|seg| seg.args.map(|args| (args.args, seg))) | |
180 | .find_map(|(args, seg)| { | |
181 | args.iter() | |
182 | .filter(|arg| arg.is_const()) | |
183 | .position(|arg| arg.id() == hir_id) | |
184 | .map(|index| (index, seg)) | |
185 | }) | |
186 | .unwrap_or_else(|| { | |
187 | bug!("no arg matching AnonConst in path"); | |
188 | }); | |
189 | ||
190 | // Try to use the segment resolution if it is valid, otherwise we | |
191 | // default to the path resolution. | |
192 | let res = segment.res.filter(|&r| r != Res::Err).unwrap_or(path.res); | |
94222f64 | 193 | use def::CtorOf; |
3dfed10e | 194 | let generics = match res { |
94222f64 XL |
195 | Res::Def(DefKind::Ctor(CtorOf::Variant, _), def_id) => tcx.generics_of( |
196 | tcx.parent(def_id).and_then(|def_id| tcx.parent(def_id)).unwrap(), | |
197 | ), | |
198 | Res::Def(DefKind::Variant | DefKind::Ctor(CtorOf::Struct, _), def_id) => { | |
3dfed10e XL |
199 | tcx.generics_of(tcx.parent(def_id).unwrap()) |
200 | } | |
cdc7bbd5 XL |
201 | // Other `DefKind`s don't have generics and would ICE when calling |
202 | // `generics_of`. | |
203 | Res::Def( | |
204 | DefKind::Struct | |
205 | | DefKind::Union | |
206 | | DefKind::Enum | |
cdc7bbd5 XL |
207 | | DefKind::Trait |
208 | | DefKind::OpaqueTy | |
209 | | DefKind::TyAlias | |
210 | | DefKind::ForeignTy | |
211 | | DefKind::TraitAlias | |
212 | | DefKind::AssocTy | |
213 | | DefKind::Fn | |
214 | | DefKind::AssocFn | |
215 | | DefKind::AssocConst | |
216 | | DefKind::Impl, | |
217 | def_id, | |
218 | ) => tcx.generics_of(def_id), | |
3dfed10e XL |
219 | Res::Err => { |
220 | tcx.sess.delay_span_bug(tcx.def_span(def_id), "anon const with Res::Err"); | |
221 | return None; | |
222 | } | |
29967ef6 XL |
223 | _ => { |
224 | // If the user tries to specify generics on a type that does not take them, | |
225 | // e.g. `usize<T>`, we may hit this branch, in which case we treat it as if | |
226 | // no arguments have been passed. An error should already have been emitted. | |
227 | tcx.sess.delay_span_bug( | |
228 | tcx.def_span(def_id), | |
229 | &format!("unexpected anon const res {:?} in path: {:?}", res, path), | |
230 | ); | |
231 | return None; | |
232 | } | |
3dfed10e XL |
233 | }; |
234 | ||
235 | generics | |
236 | .params | |
237 | .iter() | |
cdc7bbd5 | 238 | .filter(|param| matches!(param.kind, ty::GenericParamDefKind::Const { .. })) |
3dfed10e XL |
239 | .nth(arg_index) |
240 | .map(|param| param.def_id) | |
241 | } | |
242 | _ => None, | |
243 | } | |
244 | } else { | |
245 | None | |
246 | } | |
247 | } | |
248 | ||
5869c6ff XL |
249 | fn get_path_containing_arg_in_pat<'hir>( |
250 | pat: &'hir hir::Pat<'hir>, | |
251 | arg_id: HirId, | |
252 | ) -> Option<&'hir hir::Path<'hir>> { | |
253 | use hir::*; | |
254 | ||
255 | let is_arg_in_path = |p: &hir::Path<'_>| { | |
256 | p.segments | |
257 | .iter() | |
258 | .filter_map(|seg| seg.args) | |
259 | .flat_map(|args| args.args) | |
260 | .any(|arg| arg.id() == arg_id) | |
261 | }; | |
262 | let mut arg_path = None; | |
263 | pat.walk(|pat| match pat.kind { | |
264 | PatKind::Struct(QPath::Resolved(_, path), _, _) | |
265 | | PatKind::TupleStruct(QPath::Resolved(_, path), _, _) | |
266 | | PatKind::Path(QPath::Resolved(_, path)) | |
267 | if is_arg_in_path(path) => | |
268 | { | |
269 | arg_path = Some(path); | |
270 | false | |
271 | } | |
272 | _ => true, | |
273 | }); | |
274 | arg_path | |
275 | } | |
276 | ||
94222f64 XL |
277 | pub(super) fn default_anon_const_substs(tcx: TyCtxt<'_>, def_id: DefId) -> SubstsRef<'_> { |
278 | let generics = tcx.generics_of(def_id); | |
279 | if let Some(parent) = generics.parent { | |
280 | // This is the reason we bother with having optional anon const substs. | |
281 | // | |
282 | // In the future the substs of an anon const will depend on its parents predicates | |
283 | // at which point eagerly looking at them will cause a query cycle. | |
284 | // | |
285 | // So for now this is only an assurance that this approach won't cause cycle errors in | |
286 | // the future. | |
287 | let _cycle_check = tcx.predicates_of(parent); | |
288 | } | |
289 | ||
290 | let substs = InternalSubsts::identity_for_item(tcx, def_id); | |
291 | // We only expect substs with the following type flags as default substs. | |
292 | // | |
293 | // Getting this wrong can lead to ICE and unsoundness, so we assert it here. | |
294 | for arg in substs.iter() { | |
295 | let allowed_flags = ty::TypeFlags::MAY_NEED_DEFAULT_CONST_SUBSTS | |
296 | | ty::TypeFlags::STILL_FURTHER_SPECIALIZABLE; | |
297 | assert!(!arg.has_type_flags(!allowed_flags)); | |
298 | } | |
299 | substs | |
300 | } | |
301 | ||
74b04a01 | 302 | pub(super) fn type_of(tcx: TyCtxt<'_>, def_id: DefId) -> Ty<'_> { |
3dfed10e | 303 | let def_id = def_id.expect_local(); |
74b04a01 XL |
304 | use rustc_hir::*; |
305 | ||
3dfed10e | 306 | let hir_id = tcx.hir().local_def_id_to_hir_id(def_id); |
74b04a01 | 307 | |
3dfed10e | 308 | let icx = ItemCtxt::new(tcx, def_id.to_def_id()); |
74b04a01 XL |
309 | |
310 | match tcx.hir().get(hir_id) { | |
311 | Node::TraitItem(item) => match item.kind { | |
ba9703b0 | 312 | TraitItemKind::Fn(..) => { |
3dfed10e XL |
313 | let substs = InternalSubsts::identity_for_item(tcx, def_id.to_def_id()); |
314 | tcx.mk_fn_def(def_id.to_def_id(), substs) | |
74b04a01 XL |
315 | } |
316 | TraitItemKind::Const(ref ty, body_id) => body_id | |
317 | .and_then(|body_id| { | |
318 | if is_suggestable_infer_ty(ty) { | |
136023e0 XL |
319 | Some(infer_placeholder_type( |
320 | tcx, def_id, body_id, ty.span, item.ident, "constant", | |
321 | )) | |
74b04a01 XL |
322 | } else { |
323 | None | |
324 | } | |
325 | }) | |
326 | .unwrap_or_else(|| icx.to_ty(ty)), | |
327 | TraitItemKind::Type(_, Some(ref ty)) => icx.to_ty(ty), | |
328 | TraitItemKind::Type(_, None) => { | |
329 | span_bug!(item.span, "associated type missing default"); | |
330 | } | |
331 | }, | |
332 | ||
333 | Node::ImplItem(item) => match item.kind { | |
ba9703b0 | 334 | ImplItemKind::Fn(..) => { |
3dfed10e XL |
335 | let substs = InternalSubsts::identity_for_item(tcx, def_id.to_def_id()); |
336 | tcx.mk_fn_def(def_id.to_def_id(), substs) | |
74b04a01 XL |
337 | } |
338 | ImplItemKind::Const(ref ty, body_id) => { | |
339 | if is_suggestable_infer_ty(ty) { | |
136023e0 | 340 | infer_placeholder_type(tcx, def_id, body_id, ty.span, item.ident, "constant") |
74b04a01 XL |
341 | } else { |
342 | icx.to_ty(ty) | |
343 | } | |
344 | } | |
74b04a01 | 345 | ImplItemKind::TyAlias(ref ty) => { |
ba9703b0 | 346 | if tcx.impl_trait_ref(tcx.hir().get_parent_did(hir_id).to_def_id()).is_none() { |
6a06907d | 347 | check_feature_inherent_assoc_ty(tcx, item.span); |
74b04a01 XL |
348 | } |
349 | ||
350 | icx.to_ty(ty) | |
351 | } | |
352 | }, | |
353 | ||
354 | Node::Item(item) => { | |
355 | match item.kind { | |
136023e0 | 356 | ItemKind::Static(ref ty, .., body_id) => { |
74b04a01 | 357 | if is_suggestable_infer_ty(ty) { |
136023e0 XL |
358 | infer_placeholder_type( |
359 | tcx, | |
360 | def_id, | |
361 | body_id, | |
362 | ty.span, | |
363 | item.ident, | |
364 | "static variable", | |
365 | ) | |
366 | } else { | |
367 | icx.to_ty(ty) | |
368 | } | |
369 | } | |
370 | ItemKind::Const(ref ty, body_id) => { | |
371 | if is_suggestable_infer_ty(ty) { | |
372 | infer_placeholder_type( | |
373 | tcx, def_id, body_id, ty.span, item.ident, "constant", | |
374 | ) | |
74b04a01 XL |
375 | } else { |
376 | icx.to_ty(ty) | |
377 | } | |
378 | } | |
5869c6ff XL |
379 | ItemKind::TyAlias(ref self_ty, _) |
380 | | ItemKind::Impl(hir::Impl { ref self_ty, .. }) => icx.to_ty(self_ty), | |
74b04a01 | 381 | ItemKind::Fn(..) => { |
3dfed10e XL |
382 | let substs = InternalSubsts::identity_for_item(tcx, def_id.to_def_id()); |
383 | tcx.mk_fn_def(def_id.to_def_id(), substs) | |
74b04a01 XL |
384 | } |
385 | ItemKind::Enum(..) | ItemKind::Struct(..) | ItemKind::Union(..) => { | |
386 | let def = tcx.adt_def(def_id); | |
3dfed10e | 387 | let substs = InternalSubsts::identity_for_item(tcx, def_id.to_def_id()); |
74b04a01 XL |
388 | tcx.mk_adt(def, substs) |
389 | } | |
390 | ItemKind::OpaqueTy(OpaqueTy { impl_trait_fn: None, .. }) => { | |
3dfed10e | 391 | find_opaque_ty_constraints(tcx, def_id) |
74b04a01 XL |
392 | } |
393 | // Opaque types desugared from `impl Trait`. | |
f035d41b XL |
394 | ItemKind::OpaqueTy(OpaqueTy { impl_trait_fn: Some(owner), .. }) => { |
395 | let concrete_ty = tcx | |
396 | .mir_borrowck(owner.expect_local()) | |
397 | .concrete_opaque_types | |
136023e0 | 398 | .get_value_matching(|(key, _)| key.def_id == def_id.to_def_id()) |
17df50a5 | 399 | .map(|concrete_ty| *concrete_ty) |
74b04a01 XL |
400 | .unwrap_or_else(|| { |
401 | tcx.sess.delay_span_bug( | |
402 | DUMMY_SP, | |
403 | &format!( | |
3dfed10e | 404 | "owner {:?} has no opaque type for {:?} in its typeck results", |
74b04a01 XL |
405 | owner, def_id, |
406 | ), | |
407 | ); | |
ba9703b0 | 408 | if let Some(ErrorReported) = |
3dfed10e | 409 | tcx.typeck(owner.expect_local()).tainted_by_errors |
ba9703b0 | 410 | { |
74b04a01 XL |
411 | // Some error in the |
412 | // owner fn prevented us from populating | |
413 | // the `concrete_opaque_types` table. | |
f035d41b | 414 | tcx.ty_error() |
74b04a01 XL |
415 | } else { |
416 | // We failed to resolve the opaque type or it | |
417 | // resolves to itself. Return the non-revealed | |
418 | // type, which should result in E0720. | |
419 | tcx.mk_opaque( | |
3dfed10e XL |
420 | def_id.to_def_id(), |
421 | InternalSubsts::identity_for_item(tcx, def_id.to_def_id()), | |
74b04a01 XL |
422 | ) |
423 | } | |
424 | }); | |
425 | debug!("concrete_ty = {:?}", concrete_ty); | |
74b04a01 XL |
426 | concrete_ty |
427 | } | |
428 | ItemKind::Trait(..) | |
429 | | ItemKind::TraitAlias(..) | |
94222f64 | 430 | | ItemKind::Macro(..) |
74b04a01 | 431 | | ItemKind::Mod(..) |
fc512014 | 432 | | ItemKind::ForeignMod { .. } |
74b04a01 XL |
433 | | ItemKind::GlobalAsm(..) |
434 | | ItemKind::ExternCrate(..) | |
435 | | ItemKind::Use(..) => { | |
436 | span_bug!( | |
437 | item.span, | |
438 | "compute_type_of_item: unexpected item type: {:?}", | |
439 | item.kind | |
440 | ); | |
441 | } | |
442 | } | |
443 | } | |
444 | ||
445 | Node::ForeignItem(foreign_item) => match foreign_item.kind { | |
446 | ForeignItemKind::Fn(..) => { | |
3dfed10e XL |
447 | let substs = InternalSubsts::identity_for_item(tcx, def_id.to_def_id()); |
448 | tcx.mk_fn_def(def_id.to_def_id(), substs) | |
74b04a01 XL |
449 | } |
450 | ForeignItemKind::Static(ref t, _) => icx.to_ty(t), | |
3dfed10e | 451 | ForeignItemKind::Type => tcx.mk_foreign(def_id.to_def_id()), |
74b04a01 XL |
452 | }, |
453 | ||
454 | Node::Ctor(&ref def) | Node::Variant(Variant { data: ref def, .. }) => match *def { | |
455 | VariantData::Unit(..) | VariantData::Struct(..) => { | |
ba9703b0 | 456 | tcx.type_of(tcx.hir().get_parent_did(hir_id).to_def_id()) |
74b04a01 XL |
457 | } |
458 | VariantData::Tuple(..) => { | |
3dfed10e XL |
459 | let substs = InternalSubsts::identity_for_item(tcx, def_id.to_def_id()); |
460 | tcx.mk_fn_def(def_id.to_def_id(), substs) | |
74b04a01 XL |
461 | } |
462 | }, | |
463 | ||
464 | Node::Field(field) => icx.to_ty(&field.ty), | |
465 | ||
466 | Node::Expr(&Expr { kind: ExprKind::Closure(.., gen), .. }) => { | |
3dfed10e | 467 | let substs = InternalSubsts::identity_for_item(tcx, def_id.to_def_id()); |
ba9703b0 | 468 | if let Some(movability) = gen { |
3dfed10e | 469 | tcx.mk_generator(def_id.to_def_id(), substs, movability) |
ba9703b0 | 470 | } else { |
3dfed10e | 471 | tcx.mk_closure(def_id.to_def_id(), substs) |
ba9703b0 | 472 | } |
74b04a01 XL |
473 | } |
474 | ||
94222f64 XL |
475 | Node::AnonConst(_) if let Some(param) = tcx.opt_const_param_of(def_id) => { |
476 | // We defer to `type_of` of the corresponding parameter | |
477 | // for generic arguments. | |
478 | tcx.type_of(param) | |
479 | } | |
3dfed10e | 480 | |
94222f64 | 481 | Node::AnonConst(_) => { |
74b04a01 XL |
482 | let parent_node = tcx.hir().get(tcx.hir().get_parent_node(hir_id)); |
483 | match parent_node { | |
484 | Node::Ty(&Ty { kind: TyKind::Array(_, ref constant), .. }) | |
74b04a01 XL |
485 | | Node::Expr(&Expr { kind: ExprKind::Repeat(_, ref constant), .. }) |
486 | if constant.hir_id == hir_id => | |
487 | { | |
488 | tcx.types.usize | |
489 | } | |
cdc7bbd5 XL |
490 | Node::Ty(&Ty { kind: TyKind::Typeof(ref e), .. }) if e.hir_id == hir_id => { |
491 | tcx.typeck(def_id).node_type(e.hir_id) | |
492 | } | |
74b04a01 | 493 | |
29967ef6 XL |
494 | Node::Expr(&Expr { kind: ExprKind::ConstBlock(ref anon_const), .. }) |
495 | if anon_const.hir_id == hir_id => | |
496 | { | |
497 | tcx.typeck(def_id).node_type(anon_const.hir_id) | |
498 | } | |
499 | ||
17df50a5 XL |
500 | Node::Expr(&Expr { kind: ExprKind::InlineAsm(asm), .. }) |
501 | | Node::Item(&Item { kind: ItemKind::GlobalAsm(asm), .. }) | |
502 | if asm.operands.iter().any(|(op, _op_sp)| match op { | |
cdc7bbd5 XL |
503 | hir::InlineAsmOperand::Const { anon_const } => anon_const.hir_id == hir_id, |
504 | _ => false, | |
505 | }) => | |
506 | { | |
507 | tcx.typeck(def_id).node_type(hir_id) | |
508 | } | |
509 | ||
ba9703b0 XL |
510 | Node::Variant(Variant { disr_expr: Some(ref e), .. }) if e.hir_id == hir_id => tcx |
511 | .adt_def(tcx.hir().get_parent_did(hir_id).to_def_id()) | |
512 | .repr | |
513 | .discr_type() | |
514 | .to_ty(tcx), | |
74b04a01 | 515 | |
cdc7bbd5 XL |
516 | Node::GenericParam(&GenericParam { |
517 | hir_id: param_hir_id, | |
518 | kind: GenericParamKind::Const { default: Some(ct), .. }, | |
519 | .. | |
520 | }) if ct.hir_id == hir_id => tcx.type_of(tcx.hir().local_def_id(param_hir_id)), | |
521 | ||
f035d41b XL |
522 | x => tcx.ty_error_with_message( |
523 | DUMMY_SP, | |
136023e0 | 524 | &format!("unexpected const parent in type_of(): {:?}", x), |
f035d41b | 525 | ), |
74b04a01 XL |
526 | } |
527 | } | |
528 | ||
529 | Node::GenericParam(param) => match ¶m.kind { | |
3dfed10e XL |
530 | GenericParamKind::Type { default: Some(ty), .. } |
531 | | GenericParamKind::Const { ty, .. } => icx.to_ty(ty), | |
74b04a01 XL |
532 | x => bug!("unexpected non-type Node::GenericParam: {:?}", x), |
533 | }, | |
534 | ||
535 | x => { | |
136023e0 | 536 | bug!("unexpected sort of node in type_of(): {:?}", x); |
74b04a01 XL |
537 | } |
538 | } | |
539 | } | |
540 | ||
136023e0 | 541 | #[instrument(skip(tcx), level = "debug")] |
f9f354fc | 542 | fn find_opaque_ty_constraints(tcx: TyCtxt<'_>, def_id: LocalDefId) -> Ty<'_> { |
74b04a01 XL |
543 | use rustc_hir::{Expr, ImplItem, Item, TraitItem}; |
544 | ||
74b04a01 XL |
545 | struct ConstraintLocator<'tcx> { |
546 | tcx: TyCtxt<'tcx>, | |
136023e0 XL |
547 | |
548 | /// def_id of the opaque type whose defining uses are being checked | |
74b04a01 | 549 | def_id: DefId, |
136023e0 XL |
550 | |
551 | /// as we walk the defining uses, we are checking that all of them | |
552 | /// define the same hidden type. This variable is set to `Some` | |
553 | /// with the first type that we find, and then later types are | |
554 | /// checked against it (we also carry the span of that first | |
555 | /// type). | |
ba9703b0 | 556 | found: Option<(Span, Ty<'tcx>)>, |
74b04a01 XL |
557 | } |
558 | ||
559 | impl ConstraintLocator<'_> { | |
136023e0 | 560 | #[instrument(skip(self), level = "debug")] |
f9f354fc | 561 | fn check(&mut self, def_id: LocalDefId) { |
74b04a01 | 562 | // Don't try to check items that cannot possibly constrain the type. |
3dfed10e | 563 | if !self.tcx.has_typeck_results(def_id) { |
136023e0 | 564 | debug!("no constraint: no typeck results"); |
74b04a01 XL |
565 | return; |
566 | } | |
567 | // Calling `mir_borrowck` can lead to cycle errors through | |
568 | // const-checking, avoid calling it if we don't have to. | |
94222f64 | 569 | if !self.tcx.typeck(def_id).concrete_opaque_types.contains(&self.def_id) { |
136023e0 | 570 | debug!("no constraints in typeck results"); |
74b04a01 XL |
571 | return; |
572 | } | |
573 | // Use borrowck to get the type with unerased regions. | |
17df50a5 | 574 | let concrete_opaque_types = &self.tcx.mir_borrowck(def_id).concrete_opaque_types; |
136023e0 XL |
575 | debug!(?concrete_opaque_types); |
576 | for (opaque_type_key, concrete_type) in concrete_opaque_types { | |
577 | if opaque_type_key.def_id != self.def_id { | |
578 | // Ignore constraints for other opaque types. | |
579 | continue; | |
580 | } | |
581 | ||
582 | debug!(?concrete_type, ?opaque_type_key.substs, "found constraint"); | |
74b04a01 XL |
583 | |
584 | // FIXME(oli-obk): trace the actual span from inference to improve errors. | |
585 | let span = self.tcx.def_span(def_id); | |
ba9703b0 XL |
586 | |
587 | // HACK(eddyb) this check shouldn't be needed, as `wfcheck` | |
588 | // performs the same checks, in theory, but I've kept it here | |
589 | // using `delay_span_bug`, just in case `wfcheck` slips up. | |
590 | let opaque_generics = self.tcx.generics_of(self.def_id); | |
591 | let mut used_params: FxHashSet<_> = FxHashSet::default(); | |
17df50a5 | 592 | for (i, arg) in opaque_type_key.substs.iter().enumerate() { |
ba9703b0 | 593 | let arg_is_param = match arg.unpack() { |
1b1a35ee | 594 | GenericArgKind::Type(ty) => matches!(ty.kind(), ty::Param(_)), |
ba9703b0 XL |
595 | GenericArgKind::Lifetime(lt) => { |
596 | matches!(lt, ty::ReEarlyBound(_) | ty::ReFree(_)) | |
597 | } | |
598 | GenericArgKind::Const(ct) => matches!(ct.val, ty::ConstKind::Param(_)), | |
599 | }; | |
600 | ||
601 | if arg_is_param { | |
602 | if !used_params.insert(arg) { | |
603 | // There was already an entry for `arg`, meaning a generic parameter | |
604 | // was used twice. | |
74b04a01 XL |
605 | self.tcx.sess.delay_span_bug( |
606 | span, | |
607 | &format!( | |
ba9703b0 XL |
608 | "defining opaque type use restricts opaque \ |
609 | type by using the generic parameter `{}` twice", | |
610 | arg, | |
74b04a01 XL |
611 | ), |
612 | ); | |
613 | } | |
ba9703b0 XL |
614 | } else { |
615 | let param = opaque_generics.param_at(i, self.tcx); | |
616 | self.tcx.sess.delay_span_bug( | |
74b04a01 XL |
617 | span, |
618 | &format!( | |
619 | "defining opaque type use does not fully define opaque type: \ | |
ba9703b0 XL |
620 | generic parameter `{}` is specified as concrete {} `{}`", |
621 | param.name, | |
622 | param.kind.descr(), | |
623 | arg, | |
74b04a01 XL |
624 | ), |
625 | ); | |
626 | } | |
ba9703b0 XL |
627 | } |
628 | ||
629 | if let Some((prev_span, prev_ty)) = self.found { | |
630 | if *concrete_type != prev_ty { | |
136023e0 | 631 | debug!(?span); |
74b04a01 XL |
632 | // Found different concrete types for the opaque type. |
633 | let mut err = self.tcx.sess.struct_span_err( | |
634 | span, | |
635 | "concrete type differs from previous defining opaque type use", | |
636 | ); | |
637 | err.span_label( | |
638 | span, | |
639 | format!("expected `{}`, got `{}`", prev_ty, concrete_type), | |
640 | ); | |
641 | err.span_note(prev_span, "previous use here"); | |
642 | err.emit(); | |
74b04a01 XL |
643 | } |
644 | } else { | |
ba9703b0 | 645 | self.found = Some((span, concrete_type)); |
74b04a01 | 646 | } |
74b04a01 XL |
647 | } |
648 | } | |
649 | } | |
650 | ||
651 | impl<'tcx> intravisit::Visitor<'tcx> for ConstraintLocator<'tcx> { | |
652 | type Map = Map<'tcx>; | |
653 | ||
ba9703b0 XL |
654 | fn nested_visit_map(&mut self) -> intravisit::NestedVisitorMap<Self::Map> { |
655 | intravisit::NestedVisitorMap::All(self.tcx.hir()) | |
74b04a01 XL |
656 | } |
657 | fn visit_expr(&mut self, ex: &'tcx Expr<'tcx>) { | |
658 | if let hir::ExprKind::Closure(..) = ex.kind { | |
659 | let def_id = self.tcx.hir().local_def_id(ex.hir_id); | |
660 | self.check(def_id); | |
661 | } | |
662 | intravisit::walk_expr(self, ex); | |
663 | } | |
664 | fn visit_item(&mut self, it: &'tcx Item<'tcx>) { | |
665 | debug!("find_existential_constraints: visiting {:?}", it); | |
74b04a01 | 666 | // The opaque type itself or its children are not within its reveal scope. |
6a06907d XL |
667 | if it.def_id.to_def_id() != self.def_id { |
668 | self.check(it.def_id); | |
74b04a01 XL |
669 | intravisit::walk_item(self, it); |
670 | } | |
671 | } | |
672 | fn visit_impl_item(&mut self, it: &'tcx ImplItem<'tcx>) { | |
673 | debug!("find_existential_constraints: visiting {:?}", it); | |
74b04a01 | 674 | // The opaque type itself or its children are not within its reveal scope. |
6a06907d XL |
675 | if it.def_id.to_def_id() != self.def_id { |
676 | self.check(it.def_id); | |
74b04a01 XL |
677 | intravisit::walk_impl_item(self, it); |
678 | } | |
679 | } | |
680 | fn visit_trait_item(&mut self, it: &'tcx TraitItem<'tcx>) { | |
681 | debug!("find_existential_constraints: visiting {:?}", it); | |
6a06907d | 682 | self.check(it.def_id); |
74b04a01 XL |
683 | intravisit::walk_trait_item(self, it); |
684 | } | |
685 | } | |
686 | ||
3dfed10e | 687 | let hir_id = tcx.hir().local_def_id_to_hir_id(def_id); |
74b04a01 | 688 | let scope = tcx.hir().get_defining_scope(hir_id); |
f9f354fc | 689 | let mut locator = ConstraintLocator { def_id: def_id.to_def_id(), tcx, found: None }; |
74b04a01 XL |
690 | |
691 | debug!("find_opaque_ty_constraints: scope={:?}", scope); | |
692 | ||
693 | if scope == hir::CRATE_HIR_ID { | |
694 | intravisit::walk_crate(&mut locator, tcx.hir().krate()); | |
695 | } else { | |
696 | debug!("find_opaque_ty_constraints: scope={:?}", tcx.hir().get(scope)); | |
697 | match tcx.hir().get(scope) { | |
698 | // We explicitly call `visit_*` methods, instead of using `intravisit::walk_*` methods | |
699 | // This allows our visitor to process the defining item itself, causing | |
700 | // it to pick up any 'sibling' defining uses. | |
701 | // | |
702 | // For example, this code: | |
703 | // ``` | |
704 | // fn foo() { | |
705 | // type Blah = impl Debug; | |
706 | // let my_closure = || -> Blah { true }; | |
707 | // } | |
708 | // ``` | |
709 | // | |
710 | // requires us to explicitly process `foo()` in order | |
711 | // to notice the defining usage of `Blah`. | |
712 | Node::Item(ref it) => locator.visit_item(it), | |
713 | Node::ImplItem(ref it) => locator.visit_impl_item(it), | |
714 | Node::TraitItem(ref it) => locator.visit_trait_item(it), | |
715 | other => bug!("{:?} is not a valid scope for an opaque type item", other), | |
716 | } | |
717 | } | |
718 | ||
719 | match locator.found { | |
ba9703b0 | 720 | Some((_, ty)) => ty, |
74b04a01 XL |
721 | None => { |
722 | let span = tcx.def_span(def_id); | |
723 | tcx.sess.span_err(span, "could not find defining uses"); | |
f035d41b | 724 | tcx.ty_error() |
74b04a01 XL |
725 | } |
726 | } | |
727 | } | |
728 | ||
136023e0 XL |
729 | fn infer_placeholder_type<'a>( |
730 | tcx: TyCtxt<'a>, | |
f9f354fc | 731 | def_id: LocalDefId, |
74b04a01 XL |
732 | body_id: hir::BodyId, |
733 | span: Span, | |
734 | item_ident: Ident, | |
136023e0 XL |
735 | kind: &'static str, |
736 | ) -> Ty<'a> { | |
737 | // Attempts to make the type nameable by turning FnDefs into FnPtrs. | |
738 | struct MakeNameable<'tcx> { | |
739 | success: bool, | |
740 | tcx: TyCtxt<'tcx>, | |
741 | } | |
742 | ||
743 | impl<'tcx> MakeNameable<'tcx> { | |
744 | fn new(tcx: TyCtxt<'tcx>) -> Self { | |
745 | MakeNameable { success: true, tcx } | |
746 | } | |
747 | } | |
748 | ||
749 | impl TypeFolder<'tcx> for MakeNameable<'tcx> { | |
750 | fn tcx(&self) -> TyCtxt<'tcx> { | |
751 | self.tcx | |
752 | } | |
753 | ||
754 | fn fold_ty(&mut self, ty: Ty<'tcx>) -> Ty<'tcx> { | |
755 | if !self.success { | |
756 | return ty; | |
757 | } | |
758 | ||
759 | match ty.kind() { | |
760 | ty::FnDef(def_id, _) => self.tcx.mk_fn_ptr(self.tcx.fn_sig(*def_id)), | |
761 | // FIXME: non-capturing closures should also suggest a function pointer | |
762 | ty::Closure(..) | ty::Generator(..) => { | |
763 | self.success = false; | |
764 | ty | |
765 | } | |
766 | _ => ty.super_fold_with(self), | |
767 | } | |
768 | } | |
769 | } | |
770 | ||
3dfed10e | 771 | let ty = tcx.diagnostic_only_typeck(def_id).node_type(body_id.hir_id); |
74b04a01 XL |
772 | |
773 | // If this came from a free `const` or `static mut?` item, | |
774 | // then the user may have written e.g. `const A = 42;`. | |
775 | // In this case, the parser has stashed a diagnostic for | |
776 | // us to improve in typeck so we do that now. | |
777 | match tcx.sess.diagnostic().steal_diagnostic(span, StashKey::ItemNoType) { | |
778 | Some(mut err) => { | |
dc3f5686 XL |
779 | if !ty.references_error() { |
780 | // The parser provided a sub-optimal `HasPlaceholders` suggestion for the type. | |
781 | // We are typeck and have the real type, so remove that and suggest the actual type. | |
782 | err.suggestions.clear(); | |
783 | ||
784 | // Suggesting unnameable types won't help. | |
785 | let mut mk_nameable = MakeNameable::new(tcx); | |
786 | let ty = mk_nameable.fold_ty(ty); | |
787 | let sugg_ty = if mk_nameable.success { Some(ty) } else { None }; | |
788 | if let Some(sugg_ty) = sugg_ty { | |
789 | err.span_suggestion( | |
790 | span, | |
791 | &format!("provide a type for the {item}", item = kind), | |
792 | format!("{}: {}", item_ident, sugg_ty), | |
793 | Applicability::MachineApplicable, | |
794 | ); | |
795 | } else { | |
796 | err.span_note( | |
797 | tcx.hir().body(body_id).value.span, | |
798 | &format!("however, the inferred type `{}` cannot be named", ty.to_string()), | |
799 | ); | |
800 | } | |
136023e0 XL |
801 | } |
802 | ||
dc3f5686 | 803 | err.emit(); |
74b04a01 XL |
804 | } |
805 | None => { | |
136023e0 | 806 | let mut diag = bad_placeholder_type(tcx, vec![span], kind); |
6a06907d XL |
807 | |
808 | if !ty.references_error() { | |
136023e0 XL |
809 | let mut mk_nameable = MakeNameable::new(tcx); |
810 | let ty = mk_nameable.fold_ty(ty); | |
811 | let sugg_ty = if mk_nameable.success { Some(ty) } else { None }; | |
812 | if let Some(sugg_ty) = sugg_ty { | |
813 | diag.span_suggestion( | |
814 | span, | |
815 | "replace with the correct type", | |
816 | sugg_ty.to_string(), | |
817 | Applicability::MaybeIncorrect, | |
818 | ); | |
819 | } else { | |
820 | diag.span_note( | |
821 | tcx.hir().body(body_id).value.span, | |
822 | &format!("however, the inferred type `{}` cannot be named", ty.to_string()), | |
823 | ); | |
824 | } | |
74b04a01 | 825 | } |
6a06907d | 826 | |
74b04a01 XL |
827 | diag.emit(); |
828 | } | |
829 | } | |
830 | ||
ba9703b0 | 831 | // Typeck doesn't expect erased regions to be returned from `type_of`. |
fc512014 | 832 | tcx.fold_regions(ty, &mut false, |r, _| match r { |
ba9703b0 XL |
833 | ty::ReErased => tcx.lifetimes.re_static, |
834 | _ => r, | |
835 | }) | |
74b04a01 XL |
836 | } |
837 | ||
6a06907d XL |
838 | fn check_feature_inherent_assoc_ty(tcx: TyCtxt<'_>, span: Span) { |
839 | if !tcx.features().inherent_associated_types { | |
840 | use rustc_session::parse::feature_err; | |
841 | use rustc_span::symbol::sym; | |
842 | feature_err( | |
843 | &tcx.sess.parse_sess, | |
844 | sym::inherent_associated_types, | |
845 | span, | |
846 | "inherent associated types are unstable", | |
847 | ) | |
848 | .emit(); | |
849 | } | |
74b04a01 | 850 | } |