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Commit | Line | Data |
---|---|---|
064997fb | 1 | use crate::check::intrinsicck::InlineAsmCtxt; |
4b012472 | 2 | use crate::errors::LinkageType; |
923072b8 | 3 | |
9c376795 FG |
4 | use super::compare_impl_item::check_type_bounds; |
5 | use super::compare_impl_item::{compare_impl_method, compare_impl_ty}; | |
1b1a35ee | 6 | use super::*; |
1b1a35ee | 7 | use rustc_attr as attr; |
781aab86 | 8 | use rustc_errors::{ErrorGuaranteed, MultiSpan}; |
1b1a35ee | 9 | use rustc_hir as hir; |
781aab86 | 10 | use rustc_hir::def::{CtorKind, DefKind}; |
4b012472 | 11 | use rustc_hir::def_id::LocalModDefId; |
781aab86 | 12 | use rustc_hir::Node; |
49aad941 | 13 | use rustc_infer::infer::{RegionVariableOrigin, TyCtxtInferExt}; |
9ffffee4 | 14 | use rustc_infer::traits::{Obligation, TraitEngineExt as _}; |
49aad941 | 15 | use rustc_lint_defs::builtin::REPR_TRANSPARENT_EXTERNAL_PRIVATE_FIELDS; |
f2b60f7d | 16 | use rustc_middle::middle::stability::EvalResult; |
781aab86 | 17 | use rustc_middle::traits::{DefiningAnchor, ObligationCauseCode}; |
add651ee | 18 | use rustc_middle::ty::fold::BottomUpFolder; |
5e7ed085 | 19 | use rustc_middle::ty::layout::{LayoutError, MAX_SIMD_LANES}; |
cdc7bbd5 | 20 | use rustc_middle::ty::util::{Discr, IntTypeExt}; |
add651ee | 21 | use rustc_middle::ty::GenericArgKind; |
9ffffee4 | 22 | use rustc_middle::ty::{ |
4b012472 | 23 | AdtDef, ParamEnv, RegionKind, TypeSuperVisitable, TypeVisitable, TypeVisitableExt, |
9ffffee4 | 24 | }; |
136023e0 | 25 | use rustc_session::lint::builtin::{UNINHABITED_STATIC, UNSUPPORTED_CALLING_CONVENTIONS}; |
1b1a35ee | 26 | use rustc_span::symbol::sym; |
353b0b11 | 27 | use rustc_target::abi::FieldIdx; |
487cf647 | 28 | use rustc_trait_selection::traits::error_reporting::on_unimplemented::OnUnimplementedDirective; |
2b03887a | 29 | use rustc_trait_selection::traits::error_reporting::TypeErrCtxtExt as _; |
49aad941 | 30 | use rustc_trait_selection::traits::outlives_bounds::InferCtxtExt as _; |
4b012472 | 31 | use rustc_trait_selection::traits::{self, TraitEngine, TraitEngineExt as _}; |
add651ee | 32 | use rustc_type_ir::fold::TypeFoldable; |
1b1a35ee | 33 | |
29967ef6 XL |
34 | use std::ops::ControlFlow; |
35 | ||
2b03887a | 36 | pub fn check_abi(tcx: TyCtxt<'_>, hir_id: hir::HirId, span: Span, abi: Abi) { |
136023e0 XL |
37 | match tcx.sess.target.is_abi_supported(abi) { |
38 | Some(true) => (), | |
5e7ed085 FG |
39 | Some(false) => { |
40 | struct_span_err!( | |
41 | tcx.sess, | |
42 | span, | |
43 | E0570, | |
04454e1e | 44 | "`{abi}` is not a supported ABI for the current target", |
5e7ed085 FG |
45 | ) |
46 | .emit(); | |
47 | } | |
136023e0 | 48 | None => { |
2b03887a FG |
49 | tcx.struct_span_lint_hir( |
50 | UNSUPPORTED_CALLING_CONVENTIONS, | |
51 | hir_id, | |
52 | span, | |
53 | "use of calling convention not supported on this target", | |
4b012472 | 54 | |_| {}, |
2b03887a | 55 | ); |
136023e0 | 56 | } |
1b1a35ee | 57 | } |
5869c6ff XL |
58 | |
59 | // This ABI is only allowed on function pointers | |
60 | if abi == Abi::CCmseNonSecureCall { | |
61 | struct_span_err!( | |
62 | tcx.sess, | |
63 | span, | |
64 | E0781, | |
c295e0f8 | 65 | "the `\"C-cmse-nonsecure-call\"` ABI is only allowed on function pointers" |
5869c6ff | 66 | ) |
5e7ed085 | 67 | .emit(); |
5869c6ff | 68 | } |
1b1a35ee XL |
69 | } |
70 | ||
064997fb | 71 | fn check_struct(tcx: TyCtxt<'_>, def_id: LocalDefId) { |
1b1a35ee | 72 | let def = tcx.adt_def(def_id); |
064997fb | 73 | let span = tcx.def_span(def_id); |
1b1a35ee | 74 | def.destructor(tcx); // force the destructor to be evaluated |
1b1a35ee | 75 | |
5e7ed085 | 76 | if def.repr().simd() { |
1b1a35ee XL |
77 | check_simd(tcx, span, def_id); |
78 | } | |
79 | ||
487cf647 | 80 | check_transparent(tcx, def); |
1b1a35ee XL |
81 | check_packed(tcx, span, def); |
82 | } | |
83 | ||
064997fb | 84 | fn check_union(tcx: TyCtxt<'_>, def_id: LocalDefId) { |
1b1a35ee | 85 | let def = tcx.adt_def(def_id); |
064997fb | 86 | let span = tcx.def_span(def_id); |
1b1a35ee | 87 | def.destructor(tcx); // force the destructor to be evaluated |
487cf647 | 88 | check_transparent(tcx, def); |
1b1a35ee XL |
89 | check_union_fields(tcx, span, def_id); |
90 | check_packed(tcx, span, def); | |
91 | } | |
92 | ||
29967ef6 XL |
93 | /// Check that the fields of the `union` do not need dropping. |
94 | fn check_union_fields(tcx: TyCtxt<'_>, span: Span, item_def_id: LocalDefId) -> bool { | |
add651ee FG |
95 | let item_type = tcx.type_of(item_def_id).instantiate_identity(); |
96 | if let ty::Adt(def, args) = item_type.kind() { | |
1b1a35ee | 97 | assert!(def.is_union()); |
064997fb FG |
98 | |
99 | fn allowed_union_field<'tcx>( | |
100 | ty: Ty<'tcx>, | |
101 | tcx: TyCtxt<'tcx>, | |
102 | param_env: ty::ParamEnv<'tcx>, | |
064997fb FG |
103 | ) -> bool { |
104 | // We don't just accept all !needs_drop fields, due to semver concerns. | |
105 | match ty.kind() { | |
106 | ty::Ref(..) => true, // references never drop (even mutable refs, which are non-Copy and hence fail the later check) | |
107 | ty::Tuple(tys) => { | |
108 | // allow tuples of allowed types | |
9c376795 | 109 | tys.iter().all(|ty| allowed_union_field(ty, tcx, param_env)) |
064997fb FG |
110 | } |
111 | ty::Array(elem, _len) => { | |
112 | // Like `Copy`, we do *not* special-case length 0. | |
9c376795 | 113 | allowed_union_field(*elem, tcx, param_env) |
064997fb FG |
114 | } |
115 | _ => { | |
353b0b11 FG |
116 | // Fallback case: allow `ManuallyDrop` and things that are `Copy`, |
117 | // also no need to report an error if the type is unresolved. | |
064997fb | 118 | ty.ty_adt_def().is_some_and(|adt_def| adt_def.is_manually_drop()) |
2b03887a | 119 | || ty.is_copy_modulo_regions(tcx, param_env) |
353b0b11 | 120 | || ty.references_error() |
064997fb FG |
121 | } |
122 | } | |
123 | } | |
124 | ||
1b1a35ee | 125 | let param_env = tcx.param_env(item_def_id); |
064997fb | 126 | for field in &def.non_enum_variant().fields { |
ed00b5ec FG |
127 | let Ok(field_ty) = tcx.try_normalize_erasing_regions(param_env, field.ty(tcx, args)) |
128 | else { | |
4b012472 | 129 | tcx.sess.span_delayed_bug(span, "could not normalize field type"); |
ed00b5ec FG |
130 | continue; |
131 | }; | |
064997fb | 132 | |
9c376795 | 133 | if !allowed_union_field(field_ty, tcx, param_env) { |
3c0e092e XL |
134 | let (field_span, ty_span) = match tcx.hir().get_if_local(field.did) { |
135 | // We are currently checking the type this field came from, so it must be local. | |
136 | Some(Node::Field(field)) => (field.span, field.ty.span), | |
137 | _ => unreachable!("mir field has to correspond to hir field"), | |
138 | }; | |
353b0b11 | 139 | tcx.sess.emit_err(errors::InvalidUnionField { |
1b1a35ee | 140 | field_span, |
353b0b11 FG |
141 | sugg: errors::InvalidUnionFieldSuggestion { |
142 | lo: ty_span.shrink_to_lo(), | |
143 | hi: ty_span.shrink_to_hi(), | |
144 | }, | |
145 | note: (), | |
146 | }); | |
1b1a35ee | 147 | return false; |
064997fb FG |
148 | } else if field_ty.needs_drop(tcx, param_env) { |
149 | // This should never happen. But we can get here e.g. in case of name resolution errors. | |
4b012472 FG |
150 | tcx.sess |
151 | .span_delayed_bug(span, "we should never accept maybe-dropping union fields"); | |
1b1a35ee XL |
152 | } |
153 | } | |
154 | } else { | |
155 | span_bug!(span, "unions must be ty::Adt, but got {:?}", item_type.kind()); | |
156 | } | |
157 | true | |
158 | } | |
159 | ||
29967ef6 | 160 | /// Check that a `static` is inhabited. |
9c376795 | 161 | fn check_static_inhabited(tcx: TyCtxt<'_>, def_id: LocalDefId) { |
29967ef6 XL |
162 | // Make sure statics are inhabited. |
163 | // Other parts of the compiler assume that there are no uninhabited places. In principle it | |
164 | // would be enough to check this for `extern` statics, as statics with an initializer will | |
165 | // have UB during initialization if they are uninhabited, but there also seems to be no good | |
166 | // reason to allow any statics to be uninhabited. | |
add651ee | 167 | let ty = tcx.type_of(def_id).instantiate_identity(); |
064997fb | 168 | let span = tcx.def_span(def_id); |
29967ef6 XL |
169 | let layout = match tcx.layout_of(ParamEnv::reveal_all().and(ty)) { |
170 | Ok(l) => l, | |
5e7ed085 FG |
171 | // Foreign statics that overflow their allowed size should emit an error |
172 | Err(LayoutError::SizeOverflow(_)) | |
9ffffee4 FG |
173 | if matches!(tcx.def_kind(def_id), DefKind::Static(_) |
174 | if tcx.def_kind(tcx.local_parent(def_id)) == DefKind::ForeignMod) => | |
5e7ed085 | 175 | { |
49aad941 | 176 | tcx.sess.emit_err(errors::TooLargeStatic { span }); |
5e7ed085 FG |
177 | return; |
178 | } | |
179 | // Generic statics are rejected, but we still reach this case. | |
180 | Err(e) => { | |
4b012472 | 181 | tcx.sess.span_delayed_bug(span, format!("{e:?}")); |
29967ef6 XL |
182 | return; |
183 | } | |
184 | }; | |
185 | if layout.abi.is_uninhabited() { | |
186 | tcx.struct_span_lint_hir( | |
187 | UNINHABITED_STATIC, | |
4b012472 | 188 | tcx.local_def_id_to_hir_id(def_id), |
29967ef6 | 189 | span, |
2b03887a | 190 | "static of uninhabited type", |
29967ef6 | 191 | |lint| { |
2b03887a | 192 | lint |
4b012472 | 193 | .note("uninhabited statics cannot be initialized, and any access would be an immediate error"); |
29967ef6 XL |
194 | }, |
195 | ); | |
196 | } | |
197 | } | |
198 | ||
1b1a35ee XL |
199 | /// Checks that an opaque type does not contain cycles and does not use `Self` or `T::Foo` |
200 | /// projections that would result in "inheriting lifetimes". | |
9c376795 | 201 | fn check_opaque(tcx: TyCtxt<'_>, id: hir::ItemId) { |
2b03887a FG |
202 | let item = tcx.hir().item(id); |
203 | let hir::ItemKind::OpaqueTy(hir::OpaqueTy { origin, .. }) = item.kind else { | |
4b012472 | 204 | tcx.sess.span_delayed_bug(item.span, "expected opaque item"); |
2b03887a FG |
205 | return; |
206 | }; | |
207 | ||
208 | // HACK(jynelson): trying to infer the type of `impl trait` breaks documenting | |
209 | // `async-std` (and `pub async fn` in general). | |
210 | // Since rustdoc doesn't care about the concrete type behind `impl Trait`, just don't look at it! | |
211 | // See https://github.com/rust-lang/rust/issues/75100 | |
212 | if tcx.sess.opts.actually_rustdoc { | |
213 | return; | |
214 | } | |
215 | ||
add651ee | 216 | let args = GenericArgs::identity_for_item(tcx, item.owner_id); |
2b03887a FG |
217 | let span = tcx.def_span(item.owner_id.def_id); |
218 | ||
add651ee | 219 | if tcx.type_of(item.owner_id.def_id).instantiate_identity().references_error() { |
29967ef6 XL |
220 | return; |
221 | } | |
4b012472 | 222 | if check_opaque_for_cycles(tcx, item.owner_id.def_id, args, span, origin).is_err() { |
29967ef6 XL |
223 | return; |
224 | } | |
fe692bf9 | 225 | |
4b012472 | 226 | let _ = check_opaque_meets_bounds(tcx, item.owner_id.def_id, span, origin); |
1b1a35ee | 227 | } |
487cf647 | 228 | |
1b1a35ee XL |
229 | /// Checks that an opaque type does not contain cycles. |
230 | pub(super) fn check_opaque_for_cycles<'tcx>( | |
231 | tcx: TyCtxt<'tcx>, | |
232 | def_id: LocalDefId, | |
add651ee | 233 | args: GenericArgsRef<'tcx>, |
1b1a35ee XL |
234 | span: Span, |
235 | origin: &hir::OpaqueTyOrigin, | |
5e7ed085 | 236 | ) -> Result<(), ErrorGuaranteed> { |
add651ee | 237 | if tcx.try_expand_impl_trait_type(def_id.to_def_id(), args).is_err() { |
5e7ed085 | 238 | let reported = match origin { |
a2a8927a | 239 | hir::OpaqueTyOrigin::AsyncFn(..) => async_opaque_type_cycle_error(tcx, span), |
1b1a35ee | 240 | _ => opaque_type_cycle_error(tcx, def_id, span), |
5e7ed085 FG |
241 | }; |
242 | Err(reported) | |
29967ef6 XL |
243 | } else { |
244 | Ok(()) | |
1b1a35ee XL |
245 | } |
246 | } | |
247 | ||
29967ef6 XL |
248 | /// Check that the concrete type behind `impl Trait` actually implements `Trait`. |
249 | /// | |
250 | /// This is mostly checked at the places that specify the opaque type, but we | |
251 | /// check those cases in the `param_env` of that function, which may have | |
252 | /// bounds not on this opaque type: | |
253 | /// | |
2b03887a FG |
254 | /// ```ignore (illustrative) |
255 | /// type X<T> = impl Clone; | |
29967ef6 XL |
256 | /// fn f<T: Clone>(t: T) -> X<T> { |
257 | /// t | |
258 | /// } | |
2b03887a | 259 | /// ``` |
29967ef6 XL |
260 | /// |
261 | /// Without this check the above code is incorrectly accepted: we would ICE if | |
262 | /// some tried, for example, to clone an `Option<X<&mut ()>>`. | |
5099ac24 | 263 | #[instrument(level = "debug", skip(tcx))] |
29967ef6 XL |
264 | fn check_opaque_meets_bounds<'tcx>( |
265 | tcx: TyCtxt<'tcx>, | |
266 | def_id: LocalDefId, | |
29967ef6 XL |
267 | span: Span, |
268 | origin: &hir::OpaqueTyOrigin, | |
fe692bf9 | 269 | ) -> Result<(), ErrorGuaranteed> { |
5099ac24 FG |
270 | let defining_use_anchor = match *origin { |
271 | hir::OpaqueTyOrigin::FnReturn(did) | hir::OpaqueTyOrigin::AsyncFn(did) => did, | |
49aad941 | 272 | hir::OpaqueTyOrigin::TyAlias { .. } => tcx.impl_trait_parent(def_id), |
5099ac24 FG |
273 | }; |
274 | let param_env = tcx.param_env(defining_use_anchor); | |
29967ef6 | 275 | |
2b03887a FG |
276 | let infcx = tcx |
277 | .infer_ctxt() | |
278 | .with_opaque_type_inference(DefiningAnchor::Bind(defining_use_anchor)) | |
279 | .build(); | |
280 | let ocx = ObligationCtxt::new(&infcx); | |
49aad941 | 281 | |
add651ee FG |
282 | let args = match *origin { |
283 | hir::OpaqueTyOrigin::FnReturn(parent) | hir::OpaqueTyOrigin::AsyncFn(parent) => { | |
284 | GenericArgs::identity_for_item(tcx, parent).extend_to( | |
285 | tcx, | |
286 | def_id.to_def_id(), | |
287 | |param, _| tcx.map_rpit_lifetime_to_fn_lifetime(param.def_id.expect_local()).into(), | |
288 | ) | |
289 | } | |
290 | hir::OpaqueTyOrigin::TyAlias { .. } => GenericArgs::identity_for_item(tcx, def_id), | |
291 | }; | |
292 | ||
293 | let opaque_ty = Ty::new_opaque(tcx, def_id.to_def_id(), args); | |
2b03887a | 294 | |
ed00b5ec | 295 | // `ReErased` regions appear in the "parent_args" of closures/coroutines. |
2b03887a | 296 | // We're ignoring them here and replacing them with fresh region variables. |
add651ee | 297 | // See tests in ui/type-alias-impl-trait/closure_{parent_args,wf_outlives}.rs. |
2b03887a FG |
298 | // |
299 | // FIXME: Consider wrapping the hidden type in an existential `Binder` and instantiating it | |
300 | // here rather than using ReErased. | |
add651ee | 301 | let hidden_ty = tcx.type_of(def_id.to_def_id()).instantiate(tcx, args); |
2b03887a FG |
302 | let hidden_ty = tcx.fold_regions(hidden_ty, |re, _dbi| match re.kind() { |
303 | ty::ReErased => infcx.next_region_var(RegionVariableOrigin::MiscVariable(span)), | |
304 | _ => re, | |
305 | }); | |
29967ef6 | 306 | |
9ffffee4 | 307 | let misc_cause = traits::ObligationCause::misc(span, def_id); |
29967ef6 | 308 | |
487cf647 FG |
309 | match ocx.eq(&misc_cause, param_env, opaque_ty, hidden_ty) { |
310 | Ok(()) => {} | |
2b03887a | 311 | Err(ty_err) => { |
9ffffee4 | 312 | let ty_err = ty_err.to_string(tcx); |
4b012472 | 313 | return Err(tcx.sess.span_delayed_bug( |
2b03887a | 314 | span, |
49aad941 | 315 | format!("could not unify `{hidden_ty}` with revealed type:\n{ty_err}"), |
fe692bf9 | 316 | )); |
2b03887a FG |
317 | } |
318 | } | |
29967ef6 | 319 | |
2b03887a FG |
320 | // Additionally require the hidden type to be well-formed with only the generics of the opaque type. |
321 | // Defining use functions may have more bounds than the opaque type, which is ok, as long as the | |
322 | // hidden type is well formed even without those bounds. | |
fe692bf9 FG |
323 | let predicate = |
324 | ty::Binder::dummy(ty::PredicateKind::Clause(ty::ClauseKind::WellFormed(hidden_ty.into()))); | |
add651ee | 325 | ocx.register_obligation(Obligation::new(tcx, misc_cause.clone(), param_env, predicate)); |
2b03887a FG |
326 | |
327 | // Check that all obligations are satisfied by the implementation's | |
328 | // version. | |
329 | let errors = ocx.select_all_or_error(); | |
330 | if !errors.is_empty() { | |
ed00b5ec | 331 | let guar = infcx.err_ctxt().report_fulfillment_errors(errors); |
fe692bf9 | 332 | return Err(guar); |
2b03887a FG |
333 | } |
334 | match origin { | |
335 | // Checked when type checking the function containing them. | |
add651ee FG |
336 | hir::OpaqueTyOrigin::FnReturn(..) | hir::OpaqueTyOrigin::AsyncFn(..) => { |
337 | // HACK: this should also fall through to the hidden type check below, but the original | |
338 | // implementation had a bug where equivalent lifetimes are not identical. This caused us | |
339 | // to reject existing stable code that is otherwise completely fine. The real fix is to | |
340 | // compare the hidden types via our type equivalence/relation infra instead of doing an | |
341 | // identity check. | |
342 | let _ = infcx.take_opaque_types(); | |
343 | return Ok(()); | |
344 | } | |
49aad941 FG |
345 | // Nested opaque types occur only in associated types: |
346 | // ` type Opaque<T> = impl Trait<&'static T, AssocTy = impl Nested>; ` | |
347 | // They can only be referenced as `<Opaque<T> as Trait<&'static T>>::AssocTy`. | |
348 | // We don't have to check them here because their well-formedness follows from the WF of | |
349 | // the projection input types in the defining- and use-sites. | |
350 | hir::OpaqueTyOrigin::TyAlias { .. } | |
351 | if tcx.def_kind(tcx.parent(def_id.to_def_id())) == DefKind::OpaqueTy => {} | |
2b03887a | 352 | // Can have different predicates to their defining use |
49aad941 | 353 | hir::OpaqueTyOrigin::TyAlias { .. } => { |
fe692bf9 | 354 | let wf_tys = ocx.assumed_wf_types_and_report_errors(param_env, def_id)?; |
49aad941 FG |
355 | let implied_bounds = infcx.implied_bounds_tys(param_env, def_id, wf_tys); |
356 | let outlives_env = OutlivesEnvironment::with_bounds(param_env, implied_bounds); | |
fe692bf9 | 357 | ocx.resolve_regions_and_report_errors(defining_use_anchor, &outlives_env)?; |
2b03887a FG |
358 | } |
359 | } | |
add651ee FG |
360 | // Check that any hidden types found during wf checking match the hidden types that `type_of` sees. |
361 | for (mut key, mut ty) in infcx.take_opaque_types() { | |
362 | ty.hidden_type.ty = infcx.resolve_vars_if_possible(ty.hidden_type.ty); | |
363 | key = infcx.resolve_vars_if_possible(key); | |
364 | sanity_check_found_hidden_type(tcx, key, ty.hidden_type)?; | |
365 | } | |
fe692bf9 | 366 | Ok(()) |
29967ef6 XL |
367 | } |
368 | ||
add651ee FG |
369 | fn sanity_check_found_hidden_type<'tcx>( |
370 | tcx: TyCtxt<'tcx>, | |
371 | key: ty::OpaqueTypeKey<'tcx>, | |
372 | mut ty: ty::OpaqueHiddenType<'tcx>, | |
373 | ) -> Result<(), ErrorGuaranteed> { | |
374 | if ty.ty.is_ty_var() { | |
375 | // Nothing was actually constrained. | |
376 | return Ok(()); | |
377 | } | |
378 | if let ty::Alias(ty::Opaque, alias) = ty.ty.kind() { | |
379 | if alias.def_id == key.def_id.to_def_id() && alias.args == key.args { | |
380 | // Nothing was actually constrained, this is an opaque usage that was | |
381 | // only discovered to be opaque after inference vars resolved. | |
382 | return Ok(()); | |
383 | } | |
384 | } | |
385 | let strip_vars = |ty: Ty<'tcx>| { | |
386 | ty.fold_with(&mut BottomUpFolder { | |
387 | tcx, | |
388 | ty_op: |t| t, | |
389 | ct_op: |c| c, | |
390 | lt_op: |l| match l.kind() { | |
391 | RegionKind::ReVar(_) => tcx.lifetimes.re_erased, | |
392 | _ => l, | |
393 | }, | |
394 | }) | |
395 | }; | |
396 | // Closures frequently end up containing erased lifetimes in their final representation. | |
397 | // These correspond to lifetime variables that never got resolved, so we patch this up here. | |
398 | ty.ty = strip_vars(ty.ty); | |
399 | // Get the hidden type. | |
400 | let hidden_ty = tcx.type_of(key.def_id).instantiate(tcx, key.args); | |
401 | let hidden_ty = strip_vars(hidden_ty); | |
402 | ||
403 | // If the hidden types differ, emit a type mismatch diagnostic. | |
404 | if hidden_ty == ty.ty { | |
405 | Ok(()) | |
406 | } else { | |
407 | let span = tcx.def_span(key.def_id); | |
408 | let other = ty::OpaqueHiddenType { ty: hidden_ty, span }; | |
409 | Err(ty.report_mismatch(&other, key.def_id, tcx).emit()) | |
410 | } | |
411 | } | |
412 | ||
487cf647 FG |
413 | fn is_enum_of_nonnullable_ptr<'tcx>( |
414 | tcx: TyCtxt<'tcx>, | |
415 | adt_def: AdtDef<'tcx>, | |
add651ee | 416 | args: GenericArgsRef<'tcx>, |
487cf647 FG |
417 | ) -> bool { |
418 | if adt_def.repr().inhibit_enum_layout_opt() { | |
419 | return false; | |
420 | } | |
421 | ||
422 | let [var_one, var_two] = &adt_def.variants().raw[..] else { | |
423 | return false; | |
424 | }; | |
353b0b11 | 425 | let (([], [field]) | ([field], [])) = (&var_one.fields.raw[..], &var_two.fields.raw[..]) else { |
487cf647 FG |
426 | return false; |
427 | }; | |
add651ee | 428 | matches!(field.ty(tcx, args).kind(), ty::FnPtr(..) | ty::Ref(..)) |
487cf647 FG |
429 | } |
430 | ||
9c376795 | 431 | fn check_static_linkage(tcx: TyCtxt<'_>, def_id: LocalDefId) { |
487cf647 | 432 | if tcx.codegen_fn_attrs(def_id).import_linkage.is_some() { |
add651ee | 433 | if match tcx.type_of(def_id).instantiate_identity().kind() { |
487cf647 | 434 | ty::RawPtr(_) => false, |
add651ee | 435 | ty::Adt(adt_def, args) => !is_enum_of_nonnullable_ptr(tcx, *adt_def, *args), |
487cf647 FG |
436 | _ => true, |
437 | } { | |
438 | tcx.sess.emit_err(LinkageType { span: tcx.def_span(def_id) }); | |
439 | } | |
440 | } | |
441 | } | |
442 | ||
9c376795 | 443 | fn check_item_type(tcx: TyCtxt<'_>, id: hir::ItemId) { |
1b1a35ee | 444 | debug!( |
6a06907d | 445 | "check_item_type(it.def_id={:?}, it.name={})", |
2b03887a | 446 | id.owner_id, |
49aad941 | 447 | tcx.def_path_str(id.owner_id) |
1b1a35ee XL |
448 | ); |
449 | let _indenter = indenter(); | |
2b03887a | 450 | match tcx.def_kind(id.owner_id) { |
04454e1e | 451 | DefKind::Static(..) => { |
2b03887a FG |
452 | tcx.ensure().typeck(id.owner_id.def_id); |
453 | maybe_check_static_with_link_section(tcx, id.owner_id.def_id); | |
454 | check_static_inhabited(tcx, id.owner_id.def_id); | |
487cf647 | 455 | check_static_linkage(tcx, id.owner_id.def_id); |
1b1a35ee | 456 | } |
04454e1e | 457 | DefKind::Const => { |
2b03887a | 458 | tcx.ensure().typeck(id.owner_id.def_id); |
1b1a35ee | 459 | } |
04454e1e | 460 | DefKind::Enum => { |
487cf647 | 461 | check_enum(tcx, id.owner_id.def_id); |
1b1a35ee | 462 | } |
04454e1e | 463 | DefKind::Fn => {} // entirely within check_item_body |
9ffffee4 FG |
464 | DefKind::Impl { of_trait } => { |
465 | if of_trait && let Some(impl_trait_ref) = tcx.impl_trait_ref(id.owner_id) { | |
5869c6ff XL |
466 | check_impl_items_against_trait( |
467 | tcx, | |
9ffffee4 | 468 | id.owner_id.def_id, |
add651ee | 469 | impl_trait_ref.instantiate_identity(), |
5869c6ff | 470 | ); |
9ffffee4 | 471 | check_on_unimplemented(tcx, id); |
1b1a35ee XL |
472 | } |
473 | } | |
04454e1e | 474 | DefKind::Trait => { |
9ffffee4 FG |
475 | let assoc_items = tcx.associated_items(id.owner_id); |
476 | check_on_unimplemented(tcx, id); | |
477 | ||
478 | for &assoc_item in assoc_items.in_definition_order() { | |
479 | match assoc_item.kind { | |
480 | ty::AssocKind::Fn => { | |
481 | let abi = tcx.fn_sig(assoc_item.def_id).skip_binder().abi(); | |
4b012472 | 482 | forbid_intrinsic_abi(tcx, assoc_item.ident(tcx).span, abi); |
29967ef6 | 483 | } |
9ffffee4 | 484 | ty::AssocKind::Type if assoc_item.defaultness(tcx).has_value() => { |
ed00b5ec | 485 | let trait_args = GenericArgs::identity_for_item(tcx, id.owner_id); |
5e7ed085 | 486 | let _: Result<_, rustc_errors::ErrorGuaranteed> = check_type_bounds( |
29967ef6 XL |
487 | tcx, |
488 | assoc_item, | |
489 | assoc_item, | |
add651ee | 490 | ty::TraitRef::new(tcx, id.owner_id.to_def_id(), trait_args), |
29967ef6 XL |
491 | ); |
492 | } | |
493 | _ => {} | |
1b1a35ee XL |
494 | } |
495 | } | |
496 | } | |
04454e1e | 497 | DefKind::Struct => { |
2b03887a | 498 | check_struct(tcx, id.owner_id.def_id); |
1b1a35ee | 499 | } |
04454e1e | 500 | DefKind::Union => { |
2b03887a | 501 | check_union(tcx, id.owner_id.def_id); |
1b1a35ee | 502 | } |
04454e1e | 503 | DefKind::OpaqueTy => { |
fe692bf9 | 504 | let origin = tcx.opaque_type_origin(id.owner_id.def_id); |
ed00b5ec FG |
505 | if let hir::OpaqueTyOrigin::FnReturn(fn_def_id) |
506 | | hir::OpaqueTyOrigin::AsyncFn(fn_def_id) = origin | |
4b012472 | 507 | && let hir::Node::TraitItem(trait_item) = tcx.hir_node_by_def_id(fn_def_id) |
353b0b11 FG |
508 | && let (_, hir::TraitFn::Required(..)) = trait_item.expect_fn() |
509 | { | |
510 | // Skip opaques from RPIT in traits with no default body. | |
511 | } else { | |
512 | check_opaque(tcx, id); | |
513 | } | |
2b03887a | 514 | } |
781aab86 | 515 | DefKind::TyAlias => { |
add651ee | 516 | let pty_ty = tcx.type_of(id.owner_id).instantiate_identity(); |
2b03887a | 517 | let generics = tcx.generics_of(id.owner_id); |
4b012472 | 518 | check_type_params_are_used(tcx, generics, pty_ty); |
1b1a35ee | 519 | } |
04454e1e FG |
520 | DefKind::ForeignMod => { |
521 | let it = tcx.hir().item(id); | |
522 | let hir::ItemKind::ForeignMod { abi, items } = it.kind else { | |
523 | return; | |
524 | }; | |
136023e0 | 525 | check_abi(tcx, it.hir_id(), it.span, abi); |
1b1a35ee | 526 | |
9ffffee4 FG |
527 | match abi { |
528 | Abi::RustIntrinsic => { | |
529 | for item in items { | |
530 | let item = tcx.hir().foreign_item(item.id); | |
531 | intrinsic::check_intrinsic_type(tcx, item); | |
532 | } | |
1b1a35ee | 533 | } |
9ffffee4 FG |
534 | |
535 | Abi::PlatformIntrinsic => { | |
536 | for item in items { | |
537 | let item = tcx.hir().foreign_item(item.id); | |
538 | intrinsic::check_platform_intrinsic_type(tcx, item); | |
1b1a35ee | 539 | } |
9ffffee4 | 540 | } |
1b1a35ee | 541 | |
9ffffee4 FG |
542 | _ => { |
543 | for item in items { | |
544 | let def_id = item.id.owner_id.def_id; | |
545 | let generics = tcx.generics_of(def_id); | |
546 | let own_counts = generics.own_counts(); | |
547 | if generics.params.len() - own_counts.lifetimes != 0 { | |
548 | let (kinds, kinds_pl, egs) = match (own_counts.types, own_counts.consts) | |
549 | { | |
550 | (_, 0) => ("type", "types", Some("u32")), | |
551 | // We don't specify an example value, because we can't generate | |
552 | // a valid value for any type. | |
553 | (0, _) => ("const", "consts", None), | |
554 | _ => ("type or const", "types or consts", None), | |
555 | }; | |
556 | struct_span_err!( | |
557 | tcx.sess, | |
558 | item.span, | |
559 | E0044, | |
560 | "foreign items may not have {kinds} parameters", | |
561 | ) | |
49aad941 | 562 | .span_label(item.span, format!("can't have {kinds} parameters")) |
9ffffee4 FG |
563 | .help( |
564 | // FIXME: once we start storing spans for type arguments, turn this | |
565 | // into a suggestion. | |
49aad941 | 566 | format!( |
9ffffee4 FG |
567 | "replace the {} parameters with concrete {}{}", |
568 | kinds, | |
569 | kinds_pl, | |
add651ee | 570 | egs.map(|egs| format!(" like `{egs}`")).unwrap_or_default(), |
9ffffee4 FG |
571 | ), |
572 | ) | |
573 | .emit(); | |
29967ef6 | 574 | } |
9ffffee4 FG |
575 | |
576 | let item = tcx.hir().foreign_item(item.id); | |
577 | match &item.kind { | |
578 | hir::ForeignItemKind::Fn(fn_decl, _, _) => { | |
579 | require_c_abi_if_c_variadic(tcx, fn_decl, abi, item.span); | |
580 | } | |
581 | hir::ForeignItemKind::Static(..) => { | |
582 | check_static_inhabited(tcx, def_id); | |
583 | check_static_linkage(tcx, def_id); | |
584 | } | |
585 | _ => {} | |
29967ef6 | 586 | } |
1b1a35ee XL |
587 | } |
588 | } | |
589 | } | |
590 | } | |
923072b8 FG |
591 | DefKind::GlobalAsm => { |
592 | let it = tcx.hir().item(id); | |
ed00b5ec FG |
593 | let hir::ItemKind::GlobalAsm(asm) = it.kind else { |
594 | span_bug!(it.span, "DefKind::GlobalAsm but got {:#?}", it) | |
595 | }; | |
9ffffee4 | 596 | InlineAsmCtxt::new_global_asm(tcx).check_asm(asm, id.owner_id.def_id); |
923072b8 | 597 | } |
04454e1e | 598 | _ => {} |
1b1a35ee XL |
599 | } |
600 | } | |
601 | ||
9ffffee4 | 602 | pub(super) fn check_on_unimplemented(tcx: TyCtxt<'_>, item: hir::ItemId) { |
1b1a35ee | 603 | // an error would be reported if this fails. |
487cf647 | 604 | let _ = OnUnimplementedDirective::of_item(tcx, item.owner_id.to_def_id()); |
1b1a35ee XL |
605 | } |
606 | ||
607 | pub(super) fn check_specialization_validity<'tcx>( | |
608 | tcx: TyCtxt<'tcx>, | |
609 | trait_def: &ty::TraitDef, | |
9ffffee4 | 610 | trait_item: ty::AssocItem, |
1b1a35ee | 611 | impl_id: DefId, |
9ffffee4 | 612 | impl_item: DefId, |
1b1a35ee | 613 | ) { |
5e7ed085 | 614 | let Ok(ancestors) = trait_def.ancestors(tcx, impl_id) else { return }; |
5869c6ff XL |
615 | let mut ancestor_impls = ancestors.skip(1).filter_map(|parent| { |
616 | if parent.is_from_trait() { | |
617 | None | |
618 | } else { | |
5099ac24 | 619 | Some((parent, parent.item(tcx, trait_item.def_id))) |
5869c6ff XL |
620 | } |
621 | }); | |
1b1a35ee XL |
622 | |
623 | let opt_result = ancestor_impls.find_map(|(parent_impl, parent_item)| { | |
624 | match parent_item { | |
625 | // Parent impl exists, and contains the parent item we're trying to specialize, but | |
626 | // doesn't mark it `default`. | |
627 | Some(parent_item) if traits::impl_item_is_final(tcx, &parent_item) => { | |
628 | Some(Err(parent_impl.def_id())) | |
629 | } | |
630 | ||
631 | // Parent impl contains item and makes it specializable. | |
632 | Some(_) => Some(Ok(())), | |
633 | ||
634 | // Parent impl doesn't mention the item. This means it's inherited from the | |
635 | // grandparent. In that case, if parent is a `default impl`, inherited items use the | |
636 | // "defaultness" from the grandparent, else they are final. | |
637 | None => { | |
fe692bf9 | 638 | if tcx.defaultness(parent_impl.def_id()).is_default() { |
1b1a35ee XL |
639 | None |
640 | } else { | |
641 | Some(Err(parent_impl.def_id())) | |
642 | } | |
643 | } | |
644 | } | |
645 | }); | |
646 | ||
647 | // If `opt_result` is `None`, we have only encountered `default impl`s that don't contain the | |
648 | // item. This is allowed, the item isn't actually getting specialized here. | |
649 | let result = opt_result.unwrap_or(Ok(())); | |
650 | ||
651 | if let Err(parent_impl) = result { | |
fe692bf9 FG |
652 | if !tcx.is_impl_trait_in_trait(impl_item) { |
653 | report_forbidden_specialization(tcx, impl_item, parent_impl); | |
654 | } else { | |
4b012472 | 655 | tcx.sess.span_delayed_bug( |
fe692bf9 | 656 | DUMMY_SP, |
add651ee | 657 | format!("parent item: {parent_impl:?} not marked as default"), |
fe692bf9 FG |
658 | ); |
659 | } | |
1b1a35ee XL |
660 | } |
661 | } | |
662 | ||
5099ac24 | 663 | fn check_impl_items_against_trait<'tcx>( |
1b1a35ee | 664 | tcx: TyCtxt<'tcx>, |
1b1a35ee XL |
665 | impl_id: LocalDefId, |
666 | impl_trait_ref: ty::TraitRef<'tcx>, | |
1b1a35ee | 667 | ) { |
1b1a35ee XL |
668 | // If the trait reference itself is erroneous (so the compilation is going |
669 | // to fail), skip checking the items here -- the `impl_item` table in `tcx` | |
670 | // isn't populated for such impls. | |
671 | if impl_trait_ref.references_error() { | |
672 | return; | |
673 | } | |
674 | ||
9ffffee4 FG |
675 | let impl_item_refs = tcx.associated_item_def_ids(impl_id); |
676 | ||
1b1a35ee XL |
677 | // Negative impls are not expected to have any items |
678 | match tcx.impl_polarity(impl_id) { | |
679 | ty::ImplPolarity::Reservation | ty::ImplPolarity::Positive => {} | |
680 | ty::ImplPolarity::Negative => { | |
681 | if let [first_item_ref, ..] = impl_item_refs { | |
9ffffee4 | 682 | let first_item_span = tcx.def_span(first_item_ref); |
1b1a35ee XL |
683 | struct_span_err!( |
684 | tcx.sess, | |
685 | first_item_span, | |
686 | E0749, | |
687 | "negative impls cannot have any items" | |
688 | ) | |
689 | .emit(); | |
690 | } | |
691 | return; | |
692 | } | |
693 | } | |
694 | ||
1b1a35ee | 695 | let trait_def = tcx.trait_def(impl_trait_ref.def_id); |
5869c6ff | 696 | |
9ffffee4 FG |
697 | for &impl_item in impl_item_refs { |
698 | let ty_impl_item = tcx.associated_item(impl_item); | |
5099ac24 FG |
699 | let ty_trait_item = if let Some(trait_item_id) = ty_impl_item.trait_item_def_id { |
700 | tcx.associated_item(trait_item_id) | |
5869c6ff | 701 | } else { |
5099ac24 | 702 | // Checked in `associated_item`. |
4b012472 | 703 | tcx.sess.span_delayed_bug(tcx.def_span(impl_item), "missing associated item in trait"); |
5869c6ff XL |
704 | continue; |
705 | }; | |
9ffffee4 FG |
706 | match ty_impl_item.kind { |
707 | ty::AssocKind::Const => { | |
781aab86 | 708 | tcx.ensure().compare_impl_const(( |
9ffffee4 | 709 | impl_item.expect_local(), |
2b03887a FG |
710 | ty_impl_item.trait_item_def_id.unwrap(), |
711 | )); | |
5099ac24 | 712 | } |
9ffffee4 FG |
713 | ty::AssocKind::Fn => { |
714 | compare_impl_method(tcx, ty_impl_item, ty_trait_item, impl_trait_ref); | |
5099ac24 | 715 | } |
9ffffee4 FG |
716 | ty::AssocKind::Type => { |
717 | compare_impl_ty(tcx, ty_impl_item, ty_trait_item, impl_trait_ref); | |
1b1a35ee | 718 | } |
1b1a35ee | 719 | } |
5099ac24 FG |
720 | |
721 | check_specialization_validity( | |
722 | tcx, | |
723 | trait_def, | |
9ffffee4 | 724 | ty_trait_item, |
5099ac24 FG |
725 | impl_id.to_def_id(), |
726 | impl_item, | |
727 | ); | |
1b1a35ee XL |
728 | } |
729 | ||
1b1a35ee | 730 | if let Ok(ancestors) = trait_def.ancestors(tcx, impl_id.to_def_id()) { |
5869c6ff XL |
731 | // Check for missing items from trait |
732 | let mut missing_items = Vec::new(); | |
5099ac24 FG |
733 | |
734 | let mut must_implement_one_of: Option<&[Ident]> = | |
735 | trait_def.must_implement_one_of.as_deref(); | |
736 | ||
737 | for &trait_item_id in tcx.associated_item_def_ids(impl_trait_ref.def_id) { | |
9ffffee4 FG |
738 | let leaf_def = ancestors.leaf_def(tcx, trait_item_id); |
739 | ||
740 | let is_implemented = leaf_def | |
741 | .as_ref() | |
49aad941 | 742 | .is_some_and(|node_item| node_item.item.defaultness(tcx).has_value()); |
1b1a35ee | 743 | |
fe692bf9 | 744 | if !is_implemented && tcx.defaultness(impl_id).is_final() { |
5099ac24 FG |
745 | missing_items.push(tcx.associated_item(trait_item_id)); |
746 | } | |
747 | ||
f2b60f7d | 748 | // true if this item is specifically implemented in this impl |
49aad941 FG |
749 | let is_implemented_here = |
750 | leaf_def.as_ref().is_some_and(|node_item| !node_item.defining_node.is_from_trait()); | |
f2b60f7d FG |
751 | |
752 | if !is_implemented_here { | |
4b012472 | 753 | let full_impl_span = tcx.hir().span_with_body(tcx.local_def_id_to_hir_id(impl_id)); |
f2b60f7d FG |
754 | match tcx.eval_default_body_stability(trait_item_id, full_impl_span) { |
755 | EvalResult::Deny { feature, reason, issue, .. } => default_body_is_unstable( | |
756 | tcx, | |
757 | full_impl_span, | |
758 | trait_item_id, | |
759 | feature, | |
760 | reason, | |
761 | issue, | |
762 | ), | |
5099ac24 | 763 | |
f2b60f7d FG |
764 | // Unmarked default bodies are considered stable (at least for now). |
765 | EvalResult::Allow | EvalResult::Unmarked => {} | |
766 | } | |
767 | } | |
768 | ||
769 | if let Some(required_items) = &must_implement_one_of { | |
5099ac24 FG |
770 | if is_implemented_here { |
771 | let trait_item = tcx.associated_item(trait_item_id); | |
772 | if required_items.contains(&trait_item.ident(tcx)) { | |
773 | must_implement_one_of = None; | |
774 | } | |
1b1a35ee XL |
775 | } |
776 | } | |
9ffffee4 FG |
777 | |
778 | if let Some(leaf_def) = &leaf_def | |
779 | && !leaf_def.is_final() | |
780 | && let def_id = leaf_def.item.def_id | |
781 | && tcx.impl_method_has_trait_impl_trait_tys(def_id) | |
782 | { | |
783 | let def_kind = tcx.def_kind(def_id); | |
784 | let descr = tcx.def_kind_descr(def_kind, def_id); | |
785 | let (msg, feature) = if tcx.asyncness(def_id).is_async() { | |
786 | ( | |
787 | format!("async {descr} in trait cannot be specialized"), | |
ed00b5ec | 788 | "async functions in traits", |
9ffffee4 FG |
789 | ) |
790 | } else { | |
791 | ( | |
792 | format!( | |
793 | "{descr} with return-position `impl Trait` in trait cannot be specialized" | |
794 | ), | |
ed00b5ec | 795 | "return position `impl Trait` in traits", |
9ffffee4 FG |
796 | ) |
797 | }; | |
798 | tcx.sess | |
799 | .struct_span_err(tcx.def_span(def_id), msg) | |
800 | .note(format!( | |
801 | "specialization behaves in inconsistent and \ | |
ed00b5ec | 802 | surprising ways with {feature}, \ |
9ffffee4 FG |
803 | and for now is disallowed" |
804 | )) | |
805 | .emit(); | |
806 | } | |
1b1a35ee | 807 | } |
5869c6ff XL |
808 | |
809 | if !missing_items.is_empty() { | |
4b012472 | 810 | let full_impl_span = tcx.hir().span_with_body(tcx.local_def_id_to_hir_id(impl_id)); |
49aad941 | 811 | missing_items_err(tcx, impl_id, &missing_items, full_impl_span); |
5869c6ff | 812 | } |
5869c6ff | 813 | |
5099ac24 | 814 | if let Some(missing_items) = must_implement_one_of { |
5099ac24 | 815 | let attr_span = tcx |
04454e1e | 816 | .get_attr(impl_trait_ref.def_id, sym::rustc_must_implement_one_of) |
5099ac24 | 817 | .map(|attr| attr.span); |
5869c6ff | 818 | |
064997fb FG |
819 | missing_items_must_implement_one_of_err( |
820 | tcx, | |
821 | tcx.def_span(impl_id), | |
822 | missing_items, | |
823 | attr_span, | |
824 | ); | |
5869c6ff | 825 | } |
1b1a35ee XL |
826 | } |
827 | } | |
828 | ||
1b1a35ee | 829 | pub fn check_simd(tcx: TyCtxt<'_>, sp: Span, def_id: LocalDefId) { |
add651ee FG |
830 | let t = tcx.type_of(def_id).instantiate_identity(); |
831 | if let ty::Adt(def, args) = t.kind() | |
04454e1e FG |
832 | && def.is_struct() |
833 | { | |
834 | let fields = &def.non_enum_variant().fields; | |
835 | if fields.is_empty() { | |
836 | struct_span_err!(tcx.sess, sp, E0075, "SIMD vector cannot be empty").emit(); | |
837 | return; | |
838 | } | |
add651ee FG |
839 | let e = fields[FieldIdx::from_u32(0)].ty(tcx, args); |
840 | if !fields.iter().all(|f| f.ty(tcx, args) == e) { | |
04454e1e FG |
841 | struct_span_err!(tcx.sess, sp, E0076, "SIMD vector should be homogeneous") |
842 | .span_label(sp, "SIMD elements must have the same type") | |
843 | .emit(); | |
844 | return; | |
845 | } | |
846 | ||
847 | let len = if let ty::Array(_ty, c) = e.kind() { | |
9ffffee4 | 848 | c.try_eval_target_usize(tcx, tcx.param_env(def.did())) |
04454e1e FG |
849 | } else { |
850 | Some(fields.len() as u64) | |
851 | }; | |
852 | if let Some(len) = len { | |
853 | if len == 0 { | |
1b1a35ee XL |
854 | struct_span_err!(tcx.sess, sp, E0075, "SIMD vector cannot be empty").emit(); |
855 | return; | |
04454e1e FG |
856 | } else if len > MAX_SIMD_LANES { |
857 | struct_span_err!( | |
858 | tcx.sess, | |
859 | sp, | |
860 | E0075, | |
861 | "SIMD vector cannot have more than {MAX_SIMD_LANES} elements", | |
862 | ) | |
863 | .emit(); | |
1b1a35ee XL |
864 | return; |
865 | } | |
04454e1e | 866 | } |
6a06907d | 867 | |
04454e1e FG |
868 | // Check that we use types valid for use in the lanes of a SIMD "vector register" |
869 | // These are scalar types which directly match a "machine" type | |
870 | // Yes: Integers, floats, "thin" pointers | |
871 | // No: char, "fat" pointers, compound types | |
872 | match e.kind() { | |
873 | ty::Param(_) => (), // pass struct<T>(T, T, T, T) through, let monomorphization catch errors | |
874 | ty::Int(_) | ty::Uint(_) | ty::Float(_) | ty::RawPtr(_) => (), // struct(u8, u8, u8, u8) is ok | |
875 | ty::Array(t, _) if matches!(t.kind(), ty::Param(_)) => (), // pass struct<T>([T; N]) through, let monomorphization catch errors | |
876 | ty::Array(t, _clen) | |
ed00b5ec | 877 | if matches!(t.kind(), ty::Int(_) | ty::Uint(_) | ty::Float(_) | ty::RawPtr(_)) => |
04454e1e FG |
878 | { /* struct([f32; 4]) is ok */ } |
879 | _ => { | |
880 | struct_span_err!( | |
881 | tcx.sess, | |
882 | sp, | |
883 | E0077, | |
884 | "SIMD vector element type should be a \ | |
885 | primitive scalar (integer/float/pointer) type" | |
886 | ) | |
887 | .emit(); | |
888 | return; | |
1b1a35ee XL |
889 | } |
890 | } | |
891 | } | |
892 | } | |
893 | ||
5e7ed085 FG |
894 | pub(super) fn check_packed(tcx: TyCtxt<'_>, sp: Span, def: ty::AdtDef<'_>) { |
895 | let repr = def.repr(); | |
1b1a35ee | 896 | if repr.packed() { |
04454e1e | 897 | for attr in tcx.get_attrs(def.did(), sym::repr) { |
4b012472 | 898 | for r in attr::parse_repr_attr(tcx.sess, attr) { |
5e7ed085 | 899 | if let attr::ReprPacked(pack) = r |
ed00b5ec FG |
900 | && let Some(repr_pack) = repr.pack |
901 | && pack as u64 != repr_pack.bytes() | |
902 | { | |
903 | struct_span_err!( | |
904 | tcx.sess, | |
905 | sp, | |
906 | E0634, | |
907 | "type has conflicting packed representation hints" | |
908 | ) | |
909 | .emit(); | |
910 | } | |
1b1a35ee XL |
911 | } |
912 | } | |
913 | if repr.align.is_some() { | |
914 | struct_span_err!( | |
915 | tcx.sess, | |
916 | sp, | |
917 | E0587, | |
918 | "type has conflicting packed and align representation hints" | |
919 | ) | |
920 | .emit(); | |
921 | } else { | |
5e7ed085 | 922 | if let Some(def_spans) = check_packed_inner(tcx, def.did(), &mut vec![]) { |
1b1a35ee XL |
923 | let mut err = struct_span_err!( |
924 | tcx.sess, | |
925 | sp, | |
926 | E0588, | |
927 | "packed type cannot transitively contain a `#[repr(align)]` type" | |
928 | ); | |
929 | ||
930 | err.span_note( | |
931 | tcx.def_span(def_spans[0].0), | |
49aad941 | 932 | format!("`{}` has a `#[repr(align)]` attribute", tcx.item_name(def_spans[0].0)), |
1b1a35ee XL |
933 | ); |
934 | ||
935 | if def_spans.len() > 2 { | |
936 | let mut first = true; | |
937 | for (adt_def, span) in def_spans.iter().skip(1).rev() { | |
938 | let ident = tcx.item_name(*adt_def); | |
939 | err.span_note( | |
940 | *span, | |
49aad941 | 941 | if first { |
1b1a35ee XL |
942 | format!( |
943 | "`{}` contains a field of type `{}`", | |
add651ee | 944 | tcx.type_of(def.did()).instantiate_identity(), |
1b1a35ee XL |
945 | ident |
946 | ) | |
947 | } else { | |
04454e1e | 948 | format!("...which contains a field of type `{ident}`") |
1b1a35ee XL |
949 | }, |
950 | ); | |
951 | first = false; | |
952 | } | |
953 | } | |
954 | ||
955 | err.emit(); | |
956 | } | |
957 | } | |
958 | } | |
959 | } | |
960 | ||
961 | pub(super) fn check_packed_inner( | |
962 | tcx: TyCtxt<'_>, | |
963 | def_id: DefId, | |
964 | stack: &mut Vec<DefId>, | |
965 | ) -> Option<Vec<(DefId, Span)>> { | |
add651ee | 966 | if let ty::Adt(def, args) = tcx.type_of(def_id).instantiate_identity().kind() { |
1b1a35ee | 967 | if def.is_struct() || def.is_union() { |
5e7ed085 FG |
968 | if def.repr().align.is_some() { |
969 | return Some(vec![(def.did(), DUMMY_SP)]); | |
1b1a35ee XL |
970 | } |
971 | ||
972 | stack.push(def_id); | |
973 | for field in &def.non_enum_variant().fields { | |
add651ee | 974 | if let ty::Adt(def, _) = field.ty(tcx, args).kind() |
04454e1e FG |
975 | && !stack.contains(&def.did()) |
976 | && let Some(mut defs) = check_packed_inner(tcx, def.did(), stack) | |
977 | { | |
978 | defs.push((def.did(), field.ident(tcx).span)); | |
979 | return Some(defs); | |
1b1a35ee XL |
980 | } |
981 | } | |
982 | stack.pop(); | |
983 | } | |
984 | } | |
985 | ||
986 | None | |
987 | } | |
988 | ||
487cf647 | 989 | pub(super) fn check_transparent<'tcx>(tcx: TyCtxt<'tcx>, adt: ty::AdtDef<'tcx>) { |
5e7ed085 | 990 | if !adt.repr().transparent() { |
1b1a35ee XL |
991 | return; |
992 | } | |
1b1a35ee XL |
993 | |
994 | if adt.is_union() && !tcx.features().transparent_unions { | |
995 | feature_err( | |
996 | &tcx.sess.parse_sess, | |
997 | sym::transparent_unions, | |
487cf647 | 998 | tcx.def_span(adt.did()), |
1b1a35ee XL |
999 | "transparent unions are unstable", |
1000 | ) | |
1001 | .emit(); | |
1002 | } | |
1003 | ||
5e7ed085 | 1004 | if adt.variants().len() != 1 { |
487cf647 | 1005 | bad_variant_count(tcx, adt, tcx.def_span(adt.did()), adt.did()); |
9c376795 FG |
1006 | // Don't bother checking the fields. |
1007 | return; | |
1b1a35ee XL |
1008 | } |
1009 | ||
781aab86 FG |
1010 | // For each field, figure out if it's known to have "trivial" layout (i.e., is a 1-ZST), with |
1011 | // "known" respecting #[non_exhaustive] attributes. | |
1b1a35ee | 1012 | let field_infos = adt.all_fields().map(|field| { |
add651ee | 1013 | let ty = field.ty(tcx, GenericArgs::identity_for_item(tcx, field.did)); |
1b1a35ee XL |
1014 | let param_env = tcx.param_env(field.did); |
1015 | let layout = tcx.layout_of(param_env.and(ty)); | |
1016 | // We are currently checking the type this field came from, so it must be local | |
1017 | let span = tcx.hir().span_if_local(field.did).unwrap(); | |
781aab86 FG |
1018 | let trivial = layout.is_ok_and(|layout| layout.is_1zst()); |
1019 | if !trivial { | |
1020 | return (span, trivial, None); | |
064997fb | 1021 | } |
781aab86 | 1022 | // Even some 1-ZST fields are not allowed though, if they have `non_exhaustive`. |
064997fb FG |
1023 | |
1024 | fn check_non_exhaustive<'tcx>( | |
1025 | tcx: TyCtxt<'tcx>, | |
1026 | t: Ty<'tcx>, | |
add651ee | 1027 | ) -> ControlFlow<(&'static str, DefId, GenericArgsRef<'tcx>, bool)> { |
064997fb FG |
1028 | match t.kind() { |
1029 | ty::Tuple(list) => list.iter().try_for_each(|t| check_non_exhaustive(tcx, t)), | |
1030 | ty::Array(ty, _) => check_non_exhaustive(tcx, *ty), | |
1031 | ty::Adt(def, subst) => { | |
1032 | if !def.did().is_local() { | |
1033 | let non_exhaustive = def.is_variant_list_non_exhaustive() | |
1034 | || def | |
1035 | .variants() | |
1036 | .iter() | |
1037 | .any(ty::VariantDef::is_field_list_non_exhaustive); | |
1038 | let has_priv = def.all_fields().any(|f| !f.vis.is_public()); | |
1039 | if non_exhaustive || has_priv { | |
1040 | return ControlFlow::Break(( | |
1041 | def.descr(), | |
1042 | def.did(), | |
1043 | subst, | |
1044 | non_exhaustive, | |
1045 | )); | |
1046 | } | |
1047 | } | |
1048 | def.all_fields() | |
1049 | .map(|field| field.ty(tcx, subst)) | |
1050 | .try_for_each(|t| check_non_exhaustive(tcx, t)) | |
1051 | } | |
1052 | _ => ControlFlow::Continue(()), | |
1053 | } | |
1054 | } | |
1055 | ||
781aab86 | 1056 | (span, trivial, check_non_exhaustive(tcx, ty).break_value()) |
1b1a35ee XL |
1057 | }); |
1058 | ||
781aab86 | 1059 | let non_trivial_fields = field_infos |
064997fb | 1060 | .clone() |
781aab86 FG |
1061 | .filter_map(|(span, trivial, _non_exhaustive)| if !trivial { Some(span) } else { None }); |
1062 | let non_trivial_count = non_trivial_fields.clone().count(); | |
1063 | if non_trivial_count >= 2 { | |
1064 | bad_non_zero_sized_fields( | |
1065 | tcx, | |
1066 | adt, | |
1067 | non_trivial_count, | |
1068 | non_trivial_fields, | |
1069 | tcx.def_span(adt.did()), | |
1070 | ); | |
1071 | return; | |
1b1a35ee | 1072 | } |
781aab86 FG |
1073 | let mut prev_non_exhaustive_1zst = false; |
1074 | for (span, _trivial, non_exhaustive_1zst) in field_infos { | |
1075 | if let Some((descr, def_id, args, non_exhaustive)) = non_exhaustive_1zst { | |
1076 | // If there are any non-trivial fields, then there can be no non-exhaustive 1-zsts. | |
1077 | // Otherwise, it's only an issue if there's >1 non-exhaustive 1-zst. | |
1078 | if non_trivial_count > 0 || prev_non_exhaustive_1zst { | |
1079 | tcx.struct_span_lint_hir( | |
1080 | REPR_TRANSPARENT_EXTERNAL_PRIVATE_FIELDS, | |
4b012472 | 1081 | tcx.local_def_id_to_hir_id(adt.did().expect_local()), |
add651ee | 1082 | span, |
781aab86 FG |
1083 | "zero-sized fields in `repr(transparent)` cannot \ |
1084 | contain external non-exhaustive types", | |
1085 | |lint| { | |
1086 | let note = if non_exhaustive { | |
1087 | "is marked with `#[non_exhaustive]`" | |
1088 | } else { | |
1089 | "contains private fields" | |
1090 | }; | |
1091 | let field_ty = tcx.def_path_str_with_args(def_id, args); | |
1092 | lint.note(format!( | |
1093 | "this {descr} contains `{field_ty}`, which {note}, \ | |
1094 | and makes it not a breaking change to become \ | |
1095 | non-zero-sized in the future." | |
4b012472 | 1096 | )); |
781aab86 FG |
1097 | }, |
1098 | ) | |
add651ee | 1099 | } else { |
781aab86 | 1100 | prev_non_exhaustive_1zst = true; |
add651ee | 1101 | } |
064997fb | 1102 | } |
1b1a35ee XL |
1103 | } |
1104 | } | |
1105 | ||
1106 | #[allow(trivial_numeric_casts)] | |
9c376795 | 1107 | fn check_enum(tcx: TyCtxt<'_>, def_id: LocalDefId) { |
1b1a35ee XL |
1108 | let def = tcx.adt_def(def_id); |
1109 | def.destructor(tcx); // force the destructor to be evaluated | |
1110 | ||
487cf647 | 1111 | if def.variants().is_empty() { |
353b0b11 | 1112 | if let Some(attr) = tcx.get_attrs(def_id, sym::repr).next() { |
1b1a35ee XL |
1113 | struct_span_err!( |
1114 | tcx.sess, | |
1115 | attr.span, | |
1116 | E0084, | |
1117 | "unsupported representation for zero-variant enum" | |
1118 | ) | |
487cf647 | 1119 | .span_label(tcx.def_span(def_id), "zero-variant enum") |
1b1a35ee XL |
1120 | .emit(); |
1121 | } | |
1122 | } | |
1123 | ||
5e7ed085 | 1124 | let repr_type_ty = def.repr().discr_type().to_ty(tcx); |
1b1a35ee XL |
1125 | if repr_type_ty == tcx.types.i128 || repr_type_ty == tcx.types.u128 { |
1126 | if !tcx.features().repr128 { | |
1127 | feature_err( | |
1128 | &tcx.sess.parse_sess, | |
1129 | sym::repr128, | |
487cf647 | 1130 | tcx.def_span(def_id), |
1b1a35ee XL |
1131 | "repr with 128-bit type is unstable", |
1132 | ) | |
1133 | .emit(); | |
1134 | } | |
1135 | } | |
1136 | ||
487cf647 FG |
1137 | for v in def.variants() { |
1138 | if let ty::VariantDiscr::Explicit(discr_def_id) = v.discr { | |
1139 | tcx.ensure().typeck(discr_def_id.expect_local()); | |
1b1a35ee XL |
1140 | } |
1141 | } | |
1142 | ||
487cf647 FG |
1143 | if def.repr().int.is_none() { |
1144 | let is_unit = |var: &ty::VariantDef| matches!(var.ctor_kind(), Some(CtorKind::Const)); | |
1145 | let has_disr = |var: &ty::VariantDef| matches!(var.discr, ty::VariantDiscr::Explicit(_)); | |
1b1a35ee | 1146 | |
487cf647 | 1147 | let has_non_units = def.variants().iter().any(|var| !is_unit(var)); |
4b012472 FG |
1148 | let disr_units = def.variants().iter().any(|var| is_unit(var) && has_disr(var)); |
1149 | let disr_non_unit = def.variants().iter().any(|var| !is_unit(var) && has_disr(var)); | |
1b1a35ee XL |
1150 | |
1151 | if disr_non_unit || (disr_units && has_non_units) { | |
487cf647 FG |
1152 | let mut err = struct_span_err!( |
1153 | tcx.sess, | |
1154 | tcx.def_span(def_id), | |
1155 | E0732, | |
1156 | "`#[repr(inttype)]` must be specified" | |
1157 | ); | |
1b1a35ee XL |
1158 | err.emit(); |
1159 | } | |
1160 | } | |
1161 | ||
487cf647 FG |
1162 | detect_discriminant_duplicate(tcx, def); |
1163 | check_transparent(tcx, def); | |
1b1a35ee XL |
1164 | } |
1165 | ||
f2b60f7d | 1166 | /// Part of enum check. Given the discriminants of an enum, errors if two or more discriminants are equal |
487cf647 | 1167 | fn detect_discriminant_duplicate<'tcx>(tcx: TyCtxt<'tcx>, adt: ty::AdtDef<'tcx>) { |
f2b60f7d FG |
1168 | // Helper closure to reduce duplicate code. This gets called everytime we detect a duplicate. |
1169 | // Here `idx` refers to the order of which the discriminant appears, and its index in `vs` | |
487cf647 FG |
1170 | let report = |dis: Discr<'tcx>, idx, err: &mut Diagnostic| { |
1171 | let var = adt.variant(idx); // HIR for the duplicate discriminant | |
1172 | let (span, display_discr) = match var.discr { | |
1173 | ty::VariantDiscr::Explicit(discr_def_id) => { | |
f2b60f7d | 1174 | // In the case the discriminant is both a duplicate and overflowed, let the user know |
ed00b5ec | 1175 | if let hir::Node::AnonConst(expr) = |
4b012472 | 1176 | tcx.hir_node_by_def_id(discr_def_id.expect_local()) |
487cf647 | 1177 | && let hir::ExprKind::Lit(lit) = &tcx.hir().body(expr.body).value.kind |
f2b60f7d FG |
1178 | && let rustc_ast::LitKind::Int(lit_value, _int_kind) = &lit.node |
1179 | && *lit_value != dis.val | |
1180 | { | |
487cf647 | 1181 | (tcx.def_span(discr_def_id), format!("`{dis}` (overflowed from `{lit_value}`)")) |
f2b60f7d | 1182 | } else { |
487cf647 FG |
1183 | // Otherwise, format the value as-is |
1184 | (tcx.def_span(discr_def_id), format!("`{dis}`")) | |
f2b60f7d FG |
1185 | } |
1186 | } | |
487cf647 FG |
1187 | // This should not happen. |
1188 | ty::VariantDiscr::Relative(0) => (tcx.def_span(var.def_id), format!("`{dis}`")), | |
1189 | ty::VariantDiscr::Relative(distance_to_explicit) => { | |
f2b60f7d FG |
1190 | // At this point we know this discriminant is a duplicate, and was not explicitly |
1191 | // assigned by the user. Here we iterate backwards to fetch the HIR for the last | |
1192 | // explicitly assigned discriminant, and letting the user know that this was the | |
1193 | // increment startpoint, and how many steps from there leading to the duplicate | |
487cf647 FG |
1194 | if let Some(explicit_idx) = |
1195 | idx.as_u32().checked_sub(distance_to_explicit).map(VariantIdx::from_u32) | |
f2b60f7d | 1196 | { |
487cf647 FG |
1197 | let explicit_variant = adt.variant(explicit_idx); |
1198 | let ve_ident = var.name; | |
1199 | let ex_ident = explicit_variant.name; | |
1200 | let sp = if distance_to_explicit > 1 { "variants" } else { "variant" }; | |
f2b60f7d FG |
1201 | |
1202 | err.span_label( | |
487cf647 FG |
1203 | tcx.def_span(explicit_variant.def_id), |
1204 | format!( | |
1205 | "discriminant for `{ve_ident}` incremented from this startpoint \ | |
1206 | (`{ex_ident}` + {distance_to_explicit} {sp} later \ | |
1207 | => `{ve_ident}` = {dis})" | |
1208 | ), | |
f2b60f7d FG |
1209 | ); |
1210 | } | |
1211 | ||
487cf647 | 1212 | (tcx.def_span(var.def_id), format!("`{dis}`")) |
f2b60f7d FG |
1213 | } |
1214 | }; | |
1215 | ||
1216 | err.span_label(span, format!("{display_discr} assigned here")); | |
1217 | }; | |
1218 | ||
487cf647 FG |
1219 | let mut discrs = adt.discriminants(tcx).collect::<Vec<_>>(); |
1220 | ||
f2b60f7d FG |
1221 | // Here we loop through the discriminants, comparing each discriminant to another. |
1222 | // When a duplicate is detected, we instantiate an error and point to both | |
1223 | // initial and duplicate value. The duplicate discriminant is then discarded by swapping | |
1224 | // it with the last element and decrementing the `vec.len` (which is why we have to evaluate | |
1225 | // `discrs.len()` anew every iteration, and why this could be tricky to do in a functional | |
1226 | // style as we are mutating `discrs` on the fly). | |
1227 | let mut i = 0; | |
1228 | while i < discrs.len() { | |
487cf647 | 1229 | let var_i_idx = discrs[i].0; |
f2b60f7d FG |
1230 | let mut error: Option<DiagnosticBuilder<'_, _>> = None; |
1231 | ||
1232 | let mut o = i + 1; | |
1233 | while o < discrs.len() { | |
487cf647 | 1234 | let var_o_idx = discrs[o].0; |
f2b60f7d FG |
1235 | |
1236 | if discrs[i].1.val == discrs[o].1.val { | |
1237 | let err = error.get_or_insert_with(|| { | |
1238 | let mut ret = struct_span_err!( | |
1239 | tcx.sess, | |
487cf647 | 1240 | tcx.def_span(adt.did()), |
f2b60f7d FG |
1241 | E0081, |
1242 | "discriminant value `{}` assigned more than once", | |
1243 | discrs[i].1, | |
1244 | ); | |
1245 | ||
487cf647 | 1246 | report(discrs[i].1, var_i_idx, &mut ret); |
f2b60f7d FG |
1247 | |
1248 | ret | |
1249 | }); | |
1250 | ||
487cf647 | 1251 | report(discrs[o].1, var_o_idx, err); |
f2b60f7d FG |
1252 | |
1253 | // Safe to unwrap here, as we wouldn't reach this point if `discrs` was empty | |
1254 | discrs[o] = *discrs.last().unwrap(); | |
1255 | discrs.pop(); | |
1256 | } else { | |
1257 | o += 1; | |
1258 | } | |
94222f64 | 1259 | } |
923072b8 | 1260 | |
f2b60f7d FG |
1261 | if let Some(mut e) = error { |
1262 | e.emit(); | |
1263 | } | |
1264 | ||
1265 | i += 1; | |
1266 | } | |
94222f64 XL |
1267 | } |
1268 | ||
1b1a35ee XL |
1269 | pub(super) fn check_type_params_are_used<'tcx>( |
1270 | tcx: TyCtxt<'tcx>, | |
1271 | generics: &ty::Generics, | |
1272 | ty: Ty<'tcx>, | |
1273 | ) { | |
1274 | debug!("check_type_params_are_used(generics={:?}, ty={:?})", generics, ty); | |
1275 | ||
1276 | assert_eq!(generics.parent, None); | |
1277 | ||
1278 | if generics.own_counts().types == 0 { | |
1279 | return; | |
1280 | } | |
1281 | ||
1282 | let mut params_used = BitSet::new_empty(generics.params.len()); | |
1283 | ||
1284 | if ty.references_error() { | |
1285 | // If there is already another error, do not emit | |
1286 | // an error for not using a type parameter. | |
5e7ed085 | 1287 | assert!(tcx.sess.has_errors().is_some()); |
1b1a35ee XL |
1288 | return; |
1289 | } | |
1290 | ||
5099ac24 | 1291 | for leaf in ty.walk() { |
04454e1e FG |
1292 | if let GenericArgKind::Type(leaf_ty) = leaf.unpack() |
1293 | && let ty::Param(param) = leaf_ty.kind() | |
1294 | { | |
1295 | debug!("found use of ty param {:?}", param); | |
1296 | params_used.insert(param.index); | |
1b1a35ee XL |
1297 | } |
1298 | } | |
1299 | ||
1300 | for param in &generics.params { | |
04454e1e FG |
1301 | if !params_used.contains(param.index) |
1302 | && let ty::GenericParamDefKind::Type { .. } = param.kind | |
1303 | { | |
1304 | let span = tcx.def_span(param.def_id); | |
ed00b5ec FG |
1305 | struct_span_err!(tcx.sess, span, E0091, "type parameter `{}` is unused", param.name,) |
1306 | .span_label(span, "unused type parameter") | |
1307 | .emit(); | |
1b1a35ee XL |
1308 | } |
1309 | } | |
1310 | } | |
1311 | ||
add651ee | 1312 | pub(super) fn check_mod_item_types(tcx: TyCtxt<'_>, module_def_id: LocalModDefId) { |
04454e1e FG |
1313 | let module = tcx.hir_module_items(module_def_id); |
1314 | for id in module.items() { | |
1315 | check_item_type(tcx, id); | |
1316 | } | |
add651ee FG |
1317 | if module_def_id == LocalModDefId::CRATE_DEF_ID { |
1318 | super::entry::check_for_entry_fn(tcx); | |
1319 | } | |
1b1a35ee XL |
1320 | } |
1321 | ||
5e7ed085 | 1322 | fn async_opaque_type_cycle_error(tcx: TyCtxt<'_>, span: Span) -> ErrorGuaranteed { |
1b1a35ee XL |
1323 | struct_span_err!(tcx.sess, span, E0733, "recursion in an `async fn` requires boxing") |
1324 | .span_label(span, "recursive `async fn`") | |
1325 | .note("a recursive `async fn` must be rewritten to return a boxed `dyn Future`") | |
6a06907d XL |
1326 | .note( |
1327 | "consider using the `async_recursion` crate: https://crates.io/crates/async_recursion", | |
1328 | ) | |
5e7ed085 | 1329 | .emit() |
1b1a35ee XL |
1330 | } |
1331 | ||
1332 | /// Emit an error for recursive opaque types. | |
1333 | /// | |
1334 | /// If this is a return `impl Trait`, find the item's return expressions and point at them. For | |
1335 | /// direct recursion this is enough, but for indirect recursion also point at the last intermediary | |
1336 | /// `impl Trait`. | |
1337 | /// | |
1338 | /// If all the return expressions evaluate to `!`, then we explain that the error will go away | |
1339 | /// after changing it. This can happen when a user uses `panic!()` or similar as a placeholder. | |
9c376795 FG |
1340 | fn opaque_type_cycle_error( |
1341 | tcx: TyCtxt<'_>, | |
1342 | opaque_def_id: LocalDefId, | |
1343 | span: Span, | |
1344 | ) -> ErrorGuaranteed { | |
1b1a35ee XL |
1345 | let mut err = struct_span_err!(tcx.sess, span, E0720, "cannot resolve opaque type"); |
1346 | ||
1347 | let mut label = false; | |
9c376795 | 1348 | if let Some((def_id, visitor)) = get_owner_return_paths(tcx, opaque_def_id) { |
5099ac24 | 1349 | let typeck_results = tcx.typeck(def_id); |
1b1a35ee XL |
1350 | if visitor |
1351 | .returns | |
1352 | .iter() | |
1353 | .filter_map(|expr| typeck_results.node_type_opt(expr.hir_id)) | |
1354 | .all(|ty| matches!(ty.kind(), ty::Never)) | |
1355 | { | |
1356 | let spans = visitor | |
1357 | .returns | |
1358 | .iter() | |
1359 | .filter(|expr| typeck_results.node_type_opt(expr.hir_id).is_some()) | |
1360 | .map(|expr| expr.span) | |
1361 | .collect::<Vec<Span>>(); | |
1362 | let span_len = spans.len(); | |
1363 | if span_len == 1 { | |
1364 | err.span_label(spans[0], "this returned value is of `!` type"); | |
1365 | } else { | |
1366 | let mut multispan: MultiSpan = spans.clone().into(); | |
1367 | for span in spans { | |
064997fb | 1368 | multispan.push_span_label(span, "this returned value is of `!` type"); |
1b1a35ee XL |
1369 | } |
1370 | err.span_note(multispan, "these returned values have a concrete \"never\" type"); | |
1371 | } | |
1372 | err.help("this error will resolve once the item's body returns a concrete type"); | |
1373 | } else { | |
1374 | let mut seen = FxHashSet::default(); | |
1375 | seen.insert(span); | |
1376 | err.span_label(span, "recursive opaque type"); | |
1377 | label = true; | |
1378 | for (sp, ty) in visitor | |
1379 | .returns | |
1380 | .iter() | |
1381 | .filter_map(|e| typeck_results.node_type_opt(e.hir_id).map(|t| (e.span, t))) | |
1382 | .filter(|(_, ty)| !matches!(ty.kind(), ty::Never)) | |
1383 | { | |
9c376795 FG |
1384 | #[derive(Default)] |
1385 | struct OpaqueTypeCollector { | |
1386 | opaques: Vec<DefId>, | |
1387 | closures: Vec<DefId>, | |
1388 | } | |
9ffffee4 | 1389 | impl<'tcx> ty::visit::TypeVisitor<TyCtxt<'tcx>> for OpaqueTypeCollector { |
fc512014 | 1390 | fn visit_ty(&mut self, t: Ty<'tcx>) -> ControlFlow<Self::BreakTy> { |
1b1a35ee | 1391 | match *t.kind() { |
9c376795 FG |
1392 | ty::Alias(ty::Opaque, ty::AliasTy { def_id: def, .. }) => { |
1393 | self.opaques.push(def); | |
1394 | ControlFlow::Continue(()) | |
1395 | } | |
ed00b5ec | 1396 | ty::Closure(def_id, ..) | ty::Coroutine(def_id, ..) => { |
9c376795 FG |
1397 | self.closures.push(def_id); |
1398 | t.super_visit_with(self) | |
1b1a35ee XL |
1399 | } |
1400 | _ => t.super_visit_with(self), | |
1401 | } | |
1402 | } | |
1403 | } | |
9c376795 FG |
1404 | |
1405 | let mut visitor = OpaqueTypeCollector::default(); | |
1b1a35ee | 1406 | ty.visit_with(&mut visitor); |
9c376795 | 1407 | for def_id in visitor.opaques { |
1b1a35ee XL |
1408 | let ty_span = tcx.def_span(def_id); |
1409 | if !seen.contains(&ty_span) { | |
9ffffee4 | 1410 | let descr = if ty.is_impl_trait() { "opaque " } else { "" }; |
49aad941 | 1411 | err.span_label(ty_span, format!("returning this {descr}type `{ty}`")); |
1b1a35ee XL |
1412 | seen.insert(ty_span); |
1413 | } | |
49aad941 | 1414 | err.span_label(sp, format!("returning here with type `{ty}`")); |
1b1a35ee | 1415 | } |
9c376795 FG |
1416 | |
1417 | for closure_def_id in visitor.closures { | |
fe692bf9 FG |
1418 | let Some(closure_local_did) = closure_def_id.as_local() else { |
1419 | continue; | |
1420 | }; | |
9c376795 FG |
1421 | let typeck_results = tcx.typeck(closure_local_did); |
1422 | ||
1423 | let mut label_match = |ty: Ty<'_>, span| { | |
1424 | for arg in ty.walk() { | |
1425 | if let ty::GenericArgKind::Type(ty) = arg.unpack() | |
ed00b5ec FG |
1426 | && let ty::Alias( |
1427 | ty::Opaque, | |
1428 | ty::AliasTy { def_id: captured_def_id, .. }, | |
1429 | ) = *ty.kind() | |
9c376795 FG |
1430 | && captured_def_id == opaque_def_id.to_def_id() |
1431 | { | |
1432 | err.span_label( | |
1433 | span, | |
1434 | format!( | |
1435 | "{} captures itself here", | |
9ffffee4 | 1436 | tcx.def_descr(closure_def_id) |
9c376795 FG |
1437 | ), |
1438 | ); | |
1439 | } | |
1440 | } | |
1441 | }; | |
1442 | ||
1443 | // Label any closure upvars that capture the opaque | |
1444 | for capture in typeck_results.closure_min_captures_flattened(closure_local_did) | |
1445 | { | |
1446 | label_match(capture.place.ty(), capture.get_path_span(tcx)); | |
1447 | } | |
ed00b5ec | 1448 | // Label any coroutine locals that capture the opaque |
4b012472 | 1449 | if tcx.is_coroutine(closure_def_id) |
ed00b5ec | 1450 | && let Some(coroutine_layout) = tcx.mir_coroutine_witnesses(closure_def_id) |
353b0b11 | 1451 | { |
ed00b5ec | 1452 | for interior_ty in &coroutine_layout.field_tys { |
353b0b11 FG |
1453 | label_match(interior_ty.ty, interior_ty.source_info.span); |
1454 | } | |
1455 | } | |
9c376795 | 1456 | } |
1b1a35ee XL |
1457 | } |
1458 | } | |
1459 | } | |
1460 | if !label { | |
1461 | err.span_label(span, "cannot resolve opaque type"); | |
1462 | } | |
5e7ed085 | 1463 | err.emit() |
1b1a35ee | 1464 | } |
9ffffee4 | 1465 | |
4b012472 FG |
1466 | pub(super) fn check_coroutine_obligations( |
1467 | tcx: TyCtxt<'_>, | |
1468 | def_id: LocalDefId, | |
1469 | ) -> Result<(), ErrorGuaranteed> { | |
1470 | debug_assert!(tcx.is_coroutine(def_id.to_def_id())); | |
9ffffee4 FG |
1471 | |
1472 | let typeck = tcx.typeck(def_id); | |
1473 | let param_env = tcx.param_env(def_id); | |
1474 | ||
ed00b5ec FG |
1475 | let coroutine_interior_predicates = &typeck.coroutine_interior_predicates[&def_id]; |
1476 | debug!(?coroutine_interior_predicates); | |
9ffffee4 FG |
1477 | |
1478 | let infcx = tcx | |
1479 | .infer_ctxt() | |
1480 | // typeck writeback gives us predicates with their regions erased. | |
1481 | // As borrowck already has checked lifetimes, we do not need to do it again. | |
1482 | .ignoring_regions() | |
4b012472 FG |
1483 | // Bind opaque types to type checking root, as they should have been checked by borrowck, |
1484 | // but may show up in some cases, like when (root) obligations are stalled in the new solver. | |
1485 | .with_opaque_type_inference(DefiningAnchor::Bind(typeck.hir_owner.def_id)) | |
9ffffee4 FG |
1486 | .build(); |
1487 | ||
fe692bf9 | 1488 | let mut fulfillment_cx = <dyn TraitEngine<'_>>::new(&infcx); |
ed00b5ec | 1489 | for (predicate, cause) in coroutine_interior_predicates { |
9ffffee4 FG |
1490 | let obligation = Obligation::new(tcx, cause.clone(), param_env, *predicate); |
1491 | fulfillment_cx.register_predicate_obligation(&infcx, obligation); | |
1492 | } | |
781aab86 FG |
1493 | |
1494 | if (tcx.features().unsized_locals || tcx.features().unsized_fn_params) | |
ed00b5ec | 1495 | && let Some(coroutine) = tcx.mir_coroutine_witnesses(def_id) |
781aab86 | 1496 | { |
ed00b5ec | 1497 | for field_ty in coroutine.field_tys.iter() { |
781aab86 FG |
1498 | fulfillment_cx.register_bound( |
1499 | &infcx, | |
1500 | param_env, | |
1501 | field_ty.ty, | |
1502 | tcx.require_lang_item(hir::LangItem::Sized, Some(field_ty.source_info.span)), | |
1503 | ObligationCause::new( | |
1504 | field_ty.source_info.span, | |
1505 | def_id, | |
ed00b5ec | 1506 | ObligationCauseCode::SizedCoroutineInterior(def_id), |
781aab86 FG |
1507 | ), |
1508 | ); | |
1509 | } | |
1510 | } | |
1511 | ||
9ffffee4 FG |
1512 | let errors = fulfillment_cx.select_all_or_error(&infcx); |
1513 | debug!(?errors); | |
1514 | if !errors.is_empty() { | |
4b012472 | 1515 | return Err(infcx.err_ctxt().report_fulfillment_errors(errors)); |
9ffffee4 | 1516 | } |
4b012472 FG |
1517 | |
1518 | // Check that any hidden types found when checking these stalled coroutine obligations | |
1519 | // are valid. | |
1520 | for (key, ty) in infcx.take_opaque_types() { | |
1521 | let hidden_type = infcx.resolve_vars_if_possible(ty.hidden_type); | |
1522 | let key = infcx.resolve_vars_if_possible(key); | |
1523 | sanity_check_found_hidden_type(tcx, key, hidden_type)?; | |
1524 | } | |
1525 | ||
1526 | Ok(()) | |
9ffffee4 | 1527 | } |