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Commit | Line | Data |
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d9579d0f | 1 | //! Give useful errors and suggestions to users when an item can't be |
85aaf69f SL |
2 | //! found or is otherwise invalid. |
3 | ||
9fa01778 | 4 | use crate::check::FnCtxt; |
74b04a01 | 5 | use rustc_data_structures::fx::{FxHashMap, FxHashSet}; |
5e7ed085 FG |
6 | use rustc_errors::{ |
7 | pluralize, struct_span_err, Applicability, Diagnostic, DiagnosticBuilder, ErrorGuaranteed, | |
04454e1e | 8 | MultiSpan, |
5e7ed085 | 9 | }; |
dfeec247 | 10 | use rustc_hir as hir; |
04454e1e FG |
11 | use rustc_hir::def::DefKind; |
12 | use rustc_hir::def_id::DefId; | |
3dfed10e | 13 | use rustc_hir::lang_items::LangItem; |
dfeec247 | 14 | use rustc_hir::{ExprKind, Node, QPath}; |
74b04a01 | 15 | use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind}; |
5099ac24 | 16 | use rustc_middle::traits::util::supertraits; |
5e7ed085 | 17 | use rustc_middle::ty::fast_reject::{simplify_type, TreatParams}; |
ba9703b0 | 18 | use rustc_middle::ty::print::with_crate_prefix; |
5099ac24 | 19 | use rustc_middle::ty::ToPolyTraitRef; |
a2a8927a | 20 | use rustc_middle::ty::{self, DefIdTree, ToPredicate, Ty, TyCtxt, TypeFoldable}; |
3dfed10e | 21 | use rustc_span::symbol::{kw, sym, Ident}; |
04454e1e | 22 | use rustc_span::{lev_distance, source_map, ExpnKind, FileName, MacroKind, Span}; |
5e7ed085 FG |
23 | use rustc_trait_selection::traits::error_reporting::on_unimplemented::InferCtxtExt as _; |
24 | use rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt as _; | |
3c0e092e | 25 | use rustc_trait_selection::traits::{ |
5e7ed085 | 26 | FulfillmentError, Obligation, ObligationCause, ObligationCauseCode, OnUnimplementedNote, |
3c0e092e | 27 | }; |
85aaf69f | 28 | |
85aaf69f | 29 | use std::cmp::Ordering; |
6a06907d | 30 | use std::iter; |
85aaf69f | 31 | |
04454e1e FG |
32 | use super::probe::{Mode, ProbeScope}; |
33 | use super::{super::suggest_call_constructor, CandidateSource, MethodError, NoMatchData}; | |
85aaf69f | 34 | |
dc9dc135 | 35 | impl<'a, 'tcx> FnCtxt<'a, 'tcx> { |
48663c56 | 36 | fn is_fn_ty(&self, ty: Ty<'tcx>, span: Span) -> bool { |
a7813a04 | 37 | let tcx = self.tcx; |
1b1a35ee | 38 | match ty.kind() { |
0731742a XL |
39 | // Not all of these (e.g., unsafe fns) implement `FnOnce`, |
40 | // so we look for these beforehand. | |
dfeec247 | 41 | ty::Closure(..) | ty::FnDef(..) | ty::FnPtr(_) => true, |
0731742a | 42 | // If it's not a simple function, look for things which implement `FnOnce`. |
a7813a04 | 43 | _ => { |
5e7ed085 FG |
44 | let Some(fn_once) = tcx.lang_items().fn_once_trait() else { |
45 | return false; | |
3157f602 | 46 | }; |
a7813a04 | 47 | |
5099ac24 FG |
48 | // This conditional prevents us from asking to call errors and unresolved types. |
49 | // It might seem that we can use `predicate_must_hold_modulo_regions`, | |
50 | // but since a Dummy binder is used to fill in the FnOnce trait's arguments, | |
51 | // type resolution always gives a "maybe" here. | |
52 | if self.autoderef(span, ty).any(|(ty, _)| { | |
53 | info!("check deref {:?} error", ty); | |
54 | matches!(ty.kind(), ty::Error(_) | ty::Infer(_)) | |
55 | }) { | |
56 | return false; | |
57 | } | |
58 | ||
c30ab7b3 | 59 | self.autoderef(span, ty).any(|(ty, _)| { |
5099ac24 | 60 | info!("check deref {:?} impl FnOnce", ty); |
c30ab7b3 | 61 | self.probe(|_| { |
dfeec247 XL |
62 | let fn_once_substs = tcx.mk_substs_trait( |
63 | ty, | |
64 | &[self | |
65 | .next_ty_var(TypeVariableOrigin { | |
66 | kind: TypeVariableOriginKind::MiscVariable, | |
67 | span, | |
68 | }) | |
69 | .into()], | |
70 | ); | |
c30ab7b3 | 71 | let trait_ref = ty::TraitRef::new(fn_once, fn_once_substs); |
c295e0f8 | 72 | let poly_trait_ref = ty::Binder::dummy(trait_ref); |
dfeec247 XL |
73 | let obligation = Obligation::misc( |
74 | span, | |
75 | self.body_id, | |
76 | self.param_env, | |
f9f354fc | 77 | poly_trait_ref.without_const().to_predicate(tcx), |
dfeec247 | 78 | ); |
83c7162d | 79 | self.predicate_may_hold(&obligation) |
c30ab7b3 SL |
80 | }) |
81 | }) | |
54a0048b SL |
82 | } |
83 | } | |
84 | } | |
3157f602 | 85 | |
a2a8927a XL |
86 | fn is_slice_ty(&self, ty: Ty<'tcx>, span: Span) -> bool { |
87 | self.autoderef(span, ty).any(|(ty, _)| matches!(ty.kind(), ty::Slice(..) | ty::Array(..))) | |
88 | } | |
89 | ||
cdc7bbd5 | 90 | pub fn report_method_error( |
532ac7d7 | 91 | &self, |
94222f64 | 92 | mut span: Span, |
532ac7d7 | 93 | rcvr_ty: Ty<'tcx>, |
f9f354fc | 94 | item_name: Ident, |
cdc7bbd5 | 95 | source: SelfSource<'tcx>, |
532ac7d7 | 96 | error: MethodError<'tcx>, |
dfeec247 | 97 | args: Option<&'tcx [hir::Expr<'tcx>]>, |
5e7ed085 | 98 | ) -> Option<DiagnosticBuilder<'_, ErrorGuaranteed>> { |
0731742a | 99 | // Avoid suggestions when we don't know what's going on. |
a7813a04 | 100 | if rcvr_ty.references_error() { |
e1599b0c | 101 | return None; |
a7813a04 | 102 | } |
85aaf69f | 103 | |
dfeec247 | 104 | let report_candidates = |span: Span, |
5e7ed085 | 105 | err: &mut Diagnostic, |
dfeec247 XL |
106 | mut sources: Vec<CandidateSource>, |
107 | sugg_span: Span| { | |
a7813a04 XL |
108 | sources.sort(); |
109 | sources.dedup(); | |
110 | // Dynamic limit to avoid hiding just one candidate, which is silly. | |
111 | let limit = if sources.len() == 5 { 5 } else { 4 }; | |
112 | ||
113 | for (idx, source) in sources.iter().take(limit).enumerate() { | |
114 | match *source { | |
04454e1e | 115 | CandidateSource::Impl(impl_did) => { |
a7813a04 XL |
116 | // Provide the best span we can. Use the item, if local to crate, else |
117 | // the impl, if local to crate (item may be defaulted), else nothing. | |
5e7ed085 | 118 | let Some(item) = self.associated_value(impl_did, item_name).or_else(|| { |
5099ac24 FG |
119 | let impl_trait_ref = self.tcx.impl_trait_ref(impl_did)?; |
120 | self.associated_value(impl_trait_ref.def_id, item_name) | |
5e7ed085 FG |
121 | }) else { |
122 | continue; | |
48663c56 | 123 | }; |
dfeec247 XL |
124 | let note_span = self |
125 | .tcx | |
126 | .hir() | |
127 | .span_if_local(item.def_id) | |
128 | .or_else(|| self.tcx.hir().span_if_local(impl_did)); | |
a7813a04 | 129 | |
ba9703b0 | 130 | let impl_ty = self.tcx.at(span).type_of(impl_did); |
a7813a04 XL |
131 | |
132 | let insertion = match self.tcx.impl_trait_ref(impl_did) { | |
8faf50e0 | 133 | None => String::new(), |
dfeec247 XL |
134 | Some(trait_ref) => format!( |
135 | " of the trait `{}`", | |
136 | self.tcx.def_path_str(trait_ref.def_id) | |
137 | ), | |
a7813a04 XL |
138 | }; |
139 | ||
dfeec247 XL |
140 | let (note_str, idx) = if sources.len() > 1 { |
141 | ( | |
142 | format!( | |
143 | "candidate #{} is defined in an impl{} for the type `{}`", | |
94b46f34 XL |
144 | idx + 1, |
145 | insertion, | |
dfeec247 XL |
146 | impl_ty, |
147 | ), | |
148 | Some(idx + 1), | |
149 | ) | |
94b46f34 | 150 | } else { |
dfeec247 XL |
151 | ( |
152 | format!( | |
153 | "the candidate is defined in an impl{} for the type `{}`", | |
154 | insertion, impl_ty, | |
155 | ), | |
156 | None, | |
157 | ) | |
94b46f34 | 158 | }; |
a7813a04 XL |
159 | if let Some(note_span) = note_span { |
160 | // We have a span pointing to the method. Show note with snippet. | |
dfeec247 | 161 | err.span_note( |
ba9703b0 | 162 | self.tcx.sess.source_map().guess_head_span(note_span), |
dfeec247 XL |
163 | ¬e_str, |
164 | ); | |
a7813a04 XL |
165 | } else { |
166 | err.note(¬e_str); | |
167 | } | |
416331ca | 168 | if let Some(trait_ref) = self.tcx.impl_trait_ref(impl_did) { |
dfeec247 XL |
169 | let path = self.tcx.def_path_str(trait_ref.def_id); |
170 | ||
171 | let ty = match item.kind { | |
f035d41b | 172 | ty::AssocKind::Const | ty::AssocKind::Type => rcvr_ty, |
ba9703b0 | 173 | ty::AssocKind::Fn => self |
dfeec247 XL |
174 | .tcx |
175 | .fn_sig(item.def_id) | |
176 | .inputs() | |
177 | .skip_binder() | |
178 | .get(0) | |
179 | .filter(|ty| ty.is_region_ptr() && !rcvr_ty.is_region_ptr()) | |
74b04a01 | 180 | .copied() |
dfeec247 XL |
181 | .unwrap_or(rcvr_ty), |
182 | }; | |
183 | print_disambiguation_help( | |
184 | item_name, | |
185 | args, | |
186 | err, | |
187 | path, | |
188 | ty, | |
189 | item.kind, | |
ba9703b0 | 190 | item.def_id, |
dfeec247 XL |
191 | sugg_span, |
192 | idx, | |
193 | self.tcx.sess.source_map(), | |
c295e0f8 | 194 | item.fn_has_self_parameter, |
dfeec247 | 195 | ); |
416331ca | 196 | } |
a7813a04 | 197 | } |
04454e1e | 198 | CandidateSource::Trait(trait_did) => { |
5e7ed085 | 199 | let Some(item) = self.associated_value(trait_did, item_name) else { continue }; |
ba9703b0 XL |
200 | let item_span = self |
201 | .tcx | |
202 | .sess | |
203 | .source_map() | |
204 | .guess_head_span(self.tcx.def_span(item.def_id)); | |
dfeec247 XL |
205 | let idx = if sources.len() > 1 { |
206 | let msg = &format!( | |
207 | "candidate #{} is defined in the trait `{}`", | |
208 | idx + 1, | |
209 | self.tcx.def_path_str(trait_did) | |
210 | ); | |
211 | err.span_note(item_span, msg); | |
212 | Some(idx + 1) | |
94b46f34 | 213 | } else { |
dfeec247 XL |
214 | let msg = &format!( |
215 | "the candidate is defined in the trait `{}`", | |
216 | self.tcx.def_path_str(trait_did) | |
217 | ); | |
218 | err.span_note(item_span, msg); | |
219 | None | |
220 | }; | |
221 | let path = self.tcx.def_path_str(trait_did); | |
222 | print_disambiguation_help( | |
223 | item_name, | |
224 | args, | |
225 | err, | |
226 | path, | |
227 | rcvr_ty, | |
228 | item.kind, | |
ba9703b0 | 229 | item.def_id, |
dfeec247 XL |
230 | sugg_span, |
231 | idx, | |
232 | self.tcx.sess.source_map(), | |
c295e0f8 | 233 | item.fn_has_self_parameter, |
dfeec247 | 234 | ); |
9cc50fc6 | 235 | } |
54a0048b SL |
236 | } |
237 | } | |
a7813a04 XL |
238 | if sources.len() > limit { |
239 | err.note(&format!("and {} others", sources.len() - limit)); | |
240 | } | |
241 | }; | |
62682a34 | 242 | |
dfeec247 XL |
243 | let sugg_span = if let SelfSource::MethodCall(expr) = source { |
244 | // Given `foo.bar(baz)`, `expr` is `bar`, but we want to point to the whole thing. | |
245 | self.tcx.hir().expect_expr(self.tcx.hir().get_parent_node(expr.hir_id)).span | |
246 | } else { | |
247 | span | |
248 | }; | |
249 | ||
a7813a04 | 250 | match error { |
ff7c6d11 XL |
251 | MethodError::NoMatch(NoMatchData { |
252 | static_candidates: static_sources, | |
253 | unsatisfied_predicates, | |
254 | out_of_scope_traits, | |
255 | lev_candidate, | |
256 | mode, | |
ff7c6d11 | 257 | }) => { |
a7813a04 XL |
258 | let tcx = self.tcx; |
259 | ||
fc512014 | 260 | let actual = self.resolve_vars_if_possible(rcvr_ty); |
0731742a | 261 | let ty_str = self.ty_to_string(actual); |
ff7c6d11 | 262 | let is_method = mode == Mode::MethodCall; |
94b46f34 | 263 | let item_kind = if is_method { |
ff7c6d11 XL |
264 | "method" |
265 | } else if actual.is_enum() { | |
48663c56 | 266 | "variant or associated item" |
ff7c6d11 XL |
267 | } else { |
268 | match (item_name.as_str().chars().next(), actual.is_fresh_ty()) { | |
dfeec247 | 269 | (Some(name), false) if name.is_lowercase() => "function or associated item", |
ff7c6d11 | 270 | (Some(_), false) => "associated item", |
dfeec247 | 271 | (Some(_), true) | (None, false) => "variant or associated item", |
ff7c6d11 XL |
272 | (None, true) => "variant", |
273 | } | |
274 | }; | |
3c0e092e | 275 | |
04454e1e FG |
276 | if self.suggest_constraining_numerical_ty( |
277 | tcx, actual, source, span, item_kind, item_name, &ty_str, | |
278 | ) { | |
279 | return None; | |
280 | } | |
281 | ||
282 | span = item_name.span; | |
283 | ||
284 | // Don't show generic arguments when the method can't be found in any implementation (#81576). | |
285 | let mut ty_str_reported = ty_str.clone(); | |
286 | if let ty::Adt(_, generics) = actual.kind() { | |
287 | if generics.len() > 0 { | |
288 | let mut autoderef = self.autoderef(span, actual); | |
289 | let candidate_found = autoderef.any(|(ty, _)| { | |
290 | if let ty::Adt(adt_deref, _) = ty.kind() { | |
291 | self.tcx | |
292 | .inherent_impls(adt_deref.did()) | |
293 | .iter() | |
294 | .filter_map(|def_id| self.associated_value(*def_id, item_name)) | |
295 | .count() | |
296 | >= 1 | |
297 | } else { | |
298 | false | |
2c00a5a8 | 299 | } |
04454e1e FG |
300 | }); |
301 | let has_deref = autoderef.step_count() > 0; | |
302 | if !candidate_found && !has_deref && unsatisfied_predicates.is_empty() { | |
303 | if let Some((path_string, _)) = ty_str.split_once('<') { | |
304 | ty_str_reported = path_string.to_string(); | |
17df50a5 XL |
305 | } |
306 | } | |
04454e1e FG |
307 | } |
308 | } | |
17df50a5 | 309 | |
04454e1e FG |
310 | let mut err = struct_span_err!( |
311 | tcx.sess, | |
312 | span, | |
313 | E0599, | |
314 | "no {} named `{}` found for {} `{}` in the current scope", | |
315 | item_kind, | |
316 | item_name, | |
317 | actual.prefix_string(self.tcx), | |
318 | ty_str_reported, | |
319 | ); | |
320 | if actual.references_error() { | |
321 | err.downgrade_to_delayed_bug(); | |
322 | } | |
323 | ||
324 | if let Mode::MethodCall = mode && let SelfSource::MethodCall(cal) = source { | |
325 | self.suggest_await_before_method( | |
326 | &mut err, item_name, actual, cal, span, | |
327 | ); | |
328 | } | |
329 | if let Some(span) = tcx.resolutions(()).confused_type_with_std_module.get(&span) { | |
923072b8 FG |
330 | err.span_suggestion( |
331 | span.shrink_to_lo(), | |
332 | "you are looking for the module in `std`, not the primitive type", | |
333 | "std::", | |
334 | Applicability::MachineApplicable, | |
335 | ); | |
04454e1e FG |
336 | } |
337 | if let ty::RawPtr(_) = &actual.kind() { | |
338 | err.note( | |
339 | "try using `<*const T>::as_ref()` to get a reference to the \ | |
923072b8 FG |
340 | type behind the pointer: https://doc.rust-lang.org/std/\ |
341 | primitive.pointer.html#method.as_ref", | |
04454e1e FG |
342 | ); |
343 | err.note( | |
923072b8 FG |
344 | "using `<*const T>::as_ref()` on a pointer which is unaligned or points \ |
345 | to invalid or uninitialized memory is undefined behavior", | |
04454e1e | 346 | ); |
5e7ed085 FG |
347 | } |
348 | ||
94b46f34 | 349 | if let Some(def) = actual.ty_adt_def() { |
5e7ed085 | 350 | if let Some(full_sp) = tcx.hir().span_if_local(def.did()) { |
ba9703b0 | 351 | let def_sp = tcx.sess.source_map().guess_head_span(full_sp); |
dfeec247 XL |
352 | err.span_label( |
353 | def_sp, | |
354 | format!( | |
355 | "{} `{}` not found {}", | |
356 | item_kind, | |
357 | item_name, | |
358 | if def.is_enum() && !is_method { "here" } else { "for this" } | |
359 | ), | |
360 | ); | |
ff7c6d11 XL |
361 | } |
362 | } | |
363 | ||
c295e0f8 | 364 | if self.is_fn_ty(rcvr_ty, span) { |
0731742a | 365 | if let SelfSource::MethodCall(expr) = source { |
04454e1e FG |
366 | let suggest = if let ty::FnDef(def_id, _) = rcvr_ty.kind() { |
367 | if let Some(local_id) = def_id.as_local() { | |
368 | let hir_id = tcx.hir().local_def_id_to_hir_id(local_id); | |
369 | let node = tcx.hir().get(hir_id); | |
370 | let fields = node.tuple_fields(); | |
371 | if let Some(fields) = fields | |
372 | && let Some(DefKind::Ctor(of, _)) = self.tcx.opt_def_kind(local_id) { | |
373 | Some((fields.len(), of)) | |
374 | } else { | |
375 | None | |
376 | } | |
377 | } else { | |
378 | // The logic here isn't smart but `associated_item_def_ids` | |
379 | // doesn't work nicely on local. | |
380 | if let DefKind::Ctor(of, _) = tcx.def_kind(def_id) { | |
381 | let parent_def_id = tcx.parent(*def_id); | |
382 | Some((tcx.associated_item_def_ids(parent_def_id).len(), of)) | |
383 | } else { | |
384 | None | |
385 | } | |
a7813a04 | 386 | } |
04454e1e FG |
387 | } else { |
388 | None | |
389 | }; | |
390 | ||
391 | // If the function is a tuple constructor, we recommend that they call it | |
392 | if let Some((fields, kind)) = suggest { | |
393 | suggest_call_constructor(expr.span, kind, fields, &mut err); | |
394 | } else { | |
395 | // General case | |
396 | err.span_label( | |
397 | expr.span, | |
398 | "this is a function, perhaps you wish to call it", | |
399 | ); | |
62682a34 SL |
400 | } |
401 | } | |
c34b1796 | 402 | } |
85aaf69f | 403 | |
5e7ed085 FG |
404 | let mut custom_span_label = false; |
405 | ||
a7813a04 | 406 | if !static_sources.is_empty() { |
dfeec247 XL |
407 | err.note( |
408 | "found the following associated functions; to be used as methods, \ | |
74b04a01 | 409 | functions must have a `self` parameter", |
dfeec247 | 410 | ); |
94b46f34 | 411 | err.span_label(span, "this is an associated function, not a method"); |
5e7ed085 | 412 | custom_span_label = true; |
94b46f34 XL |
413 | } |
414 | if static_sources.len() == 1 { | |
04454e1e FG |
415 | let ty_str = |
416 | if let Some(CandidateSource::Impl(impl_did)) = static_sources.get(0) { | |
417 | // When the "method" is resolved through dereferencing, we really want the | |
418 | // original type that has the associated function for accurate suggestions. | |
419 | // (#61411) | |
420 | let ty = tcx.at(span).type_of(*impl_did); | |
421 | match (&ty.peel_refs().kind(), &actual.peel_refs().kind()) { | |
422 | (ty::Adt(def, _), ty::Adt(def_actual, _)) if def == def_actual => { | |
423 | // Use `actual` as it will have more `substs` filled in. | |
424 | self.ty_to_value_string(actual.peel_refs()) | |
425 | } | |
426 | _ => self.ty_to_value_string(ty.peel_refs()), | |
e74abb32 | 427 | } |
04454e1e FG |
428 | } else { |
429 | self.ty_to_value_string(actual.peel_refs()) | |
430 | }; | |
0731742a | 431 | if let SelfSource::MethodCall(expr) = source { |
e74abb32 XL |
432 | err.span_suggestion( |
433 | expr.span.to(span), | |
434 | "use associated function syntax instead", | |
435 | format!("{}::{}", ty_str, item_name), | |
436 | Applicability::MachineApplicable, | |
437 | ); | |
94b46f34 | 438 | } else { |
dfeec247 | 439 | err.help(&format!("try with `{}::{}`", ty_str, item_name,)); |
94b46f34 XL |
440 | } |
441 | ||
dfeec247 | 442 | report_candidates(span, &mut err, static_sources, sugg_span); |
94b46f34 | 443 | } else if static_sources.len() > 1 { |
dfeec247 | 444 | report_candidates(span, &mut err, static_sources, sugg_span); |
a7813a04 | 445 | } |
85aaf69f | 446 | |
5e7ed085 | 447 | let mut bound_spans = vec![]; |
74b04a01 | 448 | let mut restrict_type_params = false; |
cdc7bbd5 | 449 | let mut unsatisfied_bounds = false; |
a2a8927a XL |
450 | if item_name.name == sym::count && self.is_slice_ty(actual, span) { |
451 | let msg = "consider using `len` instead"; | |
452 | if let SelfSource::MethodCall(_expr) = source { | |
453 | err.span_suggestion_short( | |
454 | span, | |
455 | msg, | |
923072b8 | 456 | "len", |
a2a8927a XL |
457 | Applicability::MachineApplicable, |
458 | ); | |
459 | } else { | |
460 | err.span_label(span, msg); | |
461 | } | |
462 | if let Some(iterator_trait) = self.tcx.get_diagnostic_item(sym::Iterator) { | |
463 | let iterator_trait = self.tcx.def_path_str(iterator_trait); | |
464 | err.note(&format!("`count` is defined on `{iterator_trait}`, which `{actual}` does not implement")); | |
465 | } | |
466 | } else if !unsatisfied_predicates.is_empty() { | |
ba9703b0 XL |
467 | let def_span = |def_id| { |
468 | self.tcx.sess.source_map().guess_head_span(self.tcx.def_span(def_id)) | |
469 | }; | |
74b04a01 | 470 | let mut type_params = FxHashMap::default(); |
5e7ed085 FG |
471 | |
472 | // Pick out the list of unimplemented traits on the receiver. | |
473 | // This is used for custom error messages with the `#[rustc_on_unimplemented]` attribute. | |
474 | let mut unimplemented_traits = FxHashMap::default(); | |
475 | let mut unimplemented_traits_only = true; | |
476 | for (predicate, _parent_pred, cause) in &unsatisfied_predicates { | |
477 | if let (ty::PredicateKind::Trait(p), Some(cause)) = | |
478 | (predicate.kind().skip_binder(), cause.as_ref()) | |
479 | { | |
480 | if p.trait_ref.self_ty() != rcvr_ty { | |
481 | // This is necessary, not just to keep the errors clean, but also | |
482 | // because our derived obligations can wind up with a trait ref that | |
483 | // requires a different param_env to be correctly compared. | |
484 | continue; | |
485 | } | |
486 | unimplemented_traits.entry(p.trait_ref.def_id).or_insert(( | |
487 | predicate.kind().rebind(p.trait_ref), | |
488 | Obligation { | |
489 | cause: cause.clone(), | |
490 | param_env: self.param_env, | |
923072b8 | 491 | predicate: *predicate, |
5e7ed085 FG |
492 | recursion_depth: 0, |
493 | }, | |
494 | )); | |
495 | } | |
496 | } | |
497 | ||
498 | // Make sure that, if any traits other than the found ones were involved, | |
499 | // we don't don't report an unimplemented trait. | |
500 | // We don't want to say that `iter::Cloned` is not an iterator, just | |
501 | // because of some non-Clone item being iterated over. | |
502 | for (predicate, _parent_pred, _cause) in &unsatisfied_predicates { | |
503 | match predicate.kind().skip_binder() { | |
504 | ty::PredicateKind::Trait(p) | |
505 | if unimplemented_traits.contains_key(&p.trait_ref.def_id) => {} | |
506 | _ => { | |
507 | unimplemented_traits_only = false; | |
508 | break; | |
509 | } | |
510 | } | |
511 | } | |
3dfed10e | 512 | |
74b04a01 | 513 | let mut collect_type_param_suggestions = |
5099ac24 | 514 | |self_ty: Ty<'tcx>, parent_pred: ty::Predicate<'tcx>, obligation: &str| { |
3dfed10e | 515 | // We don't care about regions here, so it's fine to skip the binder here. |
94222f64 | 516 | if let (ty::Param(_), ty::PredicateKind::Trait(p)) = |
5869c6ff | 517 | (self_ty.kind(), parent_pred.kind().skip_binder()) |
74b04a01 | 518 | { |
3c0e092e XL |
519 | let node = match p.trait_ref.self_ty().kind() { |
520 | ty::Param(_) => { | |
521 | // Account for `fn` items like in `issue-35677.rs` to | |
522 | // suggest restricting its type params. | |
523 | let did = self.tcx.hir().body_owner_def_id(hir::BodyId { | |
524 | hir_id: self.body_id, | |
525 | }); | |
526 | Some( | |
527 | self.tcx | |
528 | .hir() | |
529 | .get(self.tcx.hir().local_def_id_to_hir_id(did)), | |
530 | ) | |
531 | } | |
5e7ed085 | 532 | ty::Adt(def, _) => def.did().as_local().map(|def_id| { |
3dfed10e XL |
533 | self.tcx |
534 | .hir() | |
535 | .get(self.tcx.hir().local_def_id_to_hir_id(def_id)) | |
3c0e092e XL |
536 | }), |
537 | _ => None, | |
538 | }; | |
539 | if let Some(hir::Node::Item(hir::Item { kind, .. })) = node { | |
540 | if let Some(g) = kind.generics() { | |
923072b8 FG |
541 | let key = ( |
542 | g.tail_span_for_predicate_suggestion(), | |
543 | g.add_where_or_trailing_comma(), | |
544 | ); | |
3c0e092e XL |
545 | type_params |
546 | .entry(key) | |
547 | .or_insert_with(FxHashSet::default) | |
548 | .insert(obligation.to_owned()); | |
74b04a01 XL |
549 | } |
550 | } | |
551 | } | |
552 | }; | |
553 | let mut bound_span_label = |self_ty: Ty<'_>, obligation: &str, quiet: &str| { | |
554 | let msg = format!( | |
555 | "doesn't satisfy `{}`", | |
556 | if obligation.len() > 50 { quiet } else { obligation } | |
557 | ); | |
1b1a35ee | 558 | match &self_ty.kind() { |
74b04a01 | 559 | // Point at the type that couldn't satisfy the bound. |
5e7ed085 | 560 | ty::Adt(def, _) => bound_spans.push((def_span(def.did()), msg)), |
74b04a01 XL |
561 | // Point at the trait object that couldn't satisfy the bound. |
562 | ty::Dynamic(preds, _) => { | |
fc512014 XL |
563 | for pred in preds.iter() { |
564 | match pred.skip_binder() { | |
74b04a01 XL |
565 | ty::ExistentialPredicate::Trait(tr) => { |
566 | bound_spans.push((def_span(tr.def_id), msg.clone())) | |
567 | } | |
568 | ty::ExistentialPredicate::Projection(_) | |
569 | | ty::ExistentialPredicate::AutoTrait(_) => {} | |
570 | } | |
571 | } | |
572 | } | |
573 | // Point at the closure that couldn't satisfy the bound. | |
574 | ty::Closure(def_id, _) => bound_spans | |
575 | .push((def_span(*def_id), format!("doesn't satisfy `{}`", quiet))), | |
576 | _ => {} | |
577 | } | |
578 | }; | |
f9f354fc | 579 | let mut format_pred = |pred: ty::Predicate<'tcx>| { |
5869c6ff | 580 | let bound_predicate = pred.kind(); |
29967ef6 | 581 | match bound_predicate.skip_binder() { |
5869c6ff | 582 | ty::PredicateKind::Projection(pred) => { |
29967ef6 | 583 | let pred = bound_predicate.rebind(pred); |
74b04a01 | 584 | // `<Foo as Iterator>::Item = String`. |
6a06907d XL |
585 | let projection_ty = pred.skip_binder().projection_ty; |
586 | ||
587 | let substs_with_infer_self = tcx.mk_substs( | |
c295e0f8 | 588 | iter::once(tcx.mk_ty_var(ty::TyVid::from_u32(0)).into()) |
6a06907d | 589 | .chain(projection_ty.substs.iter().skip(1)), |
74b04a01 | 590 | ); |
6a06907d XL |
591 | |
592 | let quiet_projection_ty = ty::ProjectionTy { | |
593 | substs: substs_with_infer_self, | |
594 | item_def_id: projection_ty.item_def_id, | |
595 | }; | |
596 | ||
5099ac24 | 597 | let term = pred.skip_binder().term; |
6a06907d | 598 | |
5099ac24 FG |
599 | let obligation = format!("{} = {}", projection_ty, term); |
600 | let quiet = format!("{} = {}", quiet_projection_ty, term); | |
6a06907d XL |
601 | |
602 | bound_span_label(projection_ty.self_ty(), &obligation, &quiet); | |
603 | Some((obligation, projection_ty.self_ty())) | |
74b04a01 | 604 | } |
94222f64 | 605 | ty::PredicateKind::Trait(poly_trait_ref) => { |
29967ef6 | 606 | let p = poly_trait_ref.trait_ref; |
74b04a01 XL |
607 | let self_ty = p.self_ty(); |
608 | let path = p.print_only_trait_path(); | |
609 | let obligation = format!("{}: {}", self_ty, path); | |
610 | let quiet = format!("_: {}", path); | |
611 | bound_span_label(self_ty, &obligation, &quiet); | |
612 | Some((obligation, self_ty)) | |
613 | } | |
614 | _ => None, | |
615 | } | |
616 | }; | |
3c0e092e XL |
617 | |
618 | // Find all the requirements that come from a local `impl` block. | |
619 | let mut skip_list: FxHashSet<_> = Default::default(); | |
620 | let mut spanned_predicates: FxHashMap<MultiSpan, _> = Default::default(); | |
5e7ed085 | 621 | for (data, p, parent_p, impl_def_id, cause_span) in unsatisfied_predicates |
3c0e092e XL |
622 | .iter() |
623 | .filter_map(|(p, parent, c)| c.as_ref().map(|c| (p, parent, c))) | |
a2a8927a | 624 | .filter_map(|(p, parent, c)| match c.code() { |
3c0e092e | 625 | ObligationCauseCode::ImplDerivedObligation(ref data) => { |
5e7ed085 | 626 | Some((&data.derived, p, parent, data.impl_def_id, data.span)) |
3c0e092e XL |
627 | } |
628 | _ => None, | |
629 | }) | |
630 | { | |
5099ac24 | 631 | let parent_trait_ref = data.parent_trait_pred; |
5099ac24 | 632 | let path = parent_trait_ref.print_modifiers_and_trait_path(); |
3c0e092e | 633 | let tr_self_ty = parent_trait_ref.skip_binder().self_ty(); |
5e7ed085 FG |
634 | let unsatisfied_msg = "unsatisfied trait bound introduced here".to_string(); |
635 | let derive_msg = | |
636 | "unsatisfied trait bound introduced in this `derive` macro"; | |
637 | match self.tcx.hir().get_if_local(impl_def_id) { | |
638 | // Unmet obligation comes from a `derive` macro, point at it once to | |
639 | // avoid multiple span labels pointing at the same place. | |
640 | Some(Node::Item(hir::Item { | |
641 | kind: hir::ItemKind::Trait(..), | |
642 | ident, | |
643 | .. | |
644 | })) if matches!( | |
645 | ident.span.ctxt().outer_expn_data().kind, | |
646 | ExpnKind::Macro(MacroKind::Derive, _) | |
647 | ) => | |
648 | { | |
649 | let span = ident.span.ctxt().outer_expn_data().call_site; | |
650 | let mut spans: MultiSpan = span.into(); | |
651 | spans.push_span_label(span, derive_msg.to_string()); | |
652 | let entry = spanned_predicates.entry(spans); | |
653 | entry.or_insert_with(|| (path, tr_self_ty, Vec::new())).2.push(p); | |
654 | } | |
655 | ||
656 | Some(Node::Item(hir::Item { | |
657 | kind: hir::ItemKind::Impl(hir::Impl { of_trait, self_ty, .. }), | |
658 | .. | |
659 | })) if matches!( | |
660 | self_ty.span.ctxt().outer_expn_data().kind, | |
661 | ExpnKind::Macro(MacroKind::Derive, _) | |
662 | ) || matches!( | |
663 | of_trait.as_ref().map(|t| t | |
664 | .path | |
665 | .span | |
666 | .ctxt() | |
667 | .outer_expn_data() | |
668 | .kind), | |
669 | Some(ExpnKind::Macro(MacroKind::Derive, _)) | |
670 | ) => | |
671 | { | |
672 | let span = self_ty.span.ctxt().outer_expn_data().call_site; | |
673 | let mut spans: MultiSpan = span.into(); | |
674 | spans.push_span_label(span, derive_msg.to_string()); | |
923072b8 | 675 | let entry = spanned_predicates.entry(spans); |
5e7ed085 FG |
676 | entry.or_insert_with(|| (path, tr_self_ty, Vec::new())).2.push(p); |
677 | } | |
678 | ||
679 | // Unmet obligation coming from a `trait`. | |
680 | Some(Node::Item(hir::Item { | |
681 | kind: hir::ItemKind::Trait(..), | |
682 | ident, | |
683 | span: item_span, | |
684 | .. | |
685 | })) if !matches!( | |
686 | ident.span.ctxt().outer_expn_data().kind, | |
687 | ExpnKind::Macro(MacroKind::Derive, _) | |
688 | ) => | |
689 | { | |
690 | if let Some(pred) = parent_p { | |
691 | // Done to add the "doesn't satisfy" `span_label`. | |
692 | let _ = format_pred(*pred); | |
3c0e092e | 693 | } |
5e7ed085 FG |
694 | skip_list.insert(p); |
695 | let mut spans = if cause_span != *item_span { | |
696 | let mut spans: MultiSpan = cause_span.into(); | |
697 | spans.push_span_label(cause_span, unsatisfied_msg); | |
698 | spans | |
699 | } else { | |
700 | ident.span.into() | |
701 | }; | |
702 | spans.push_span_label(ident.span, "in this trait".to_string()); | |
923072b8 | 703 | let entry = spanned_predicates.entry(spans); |
5e7ed085 FG |
704 | entry.or_insert_with(|| (path, tr_self_ty, Vec::new())).2.push(p); |
705 | } | |
706 | ||
707 | // Unmet obligation coming from an `impl`. | |
708 | Some(Node::Item(hir::Item { | |
709 | kind: hir::ItemKind::Impl(hir::Impl { of_trait, self_ty, .. }), | |
710 | span: item_span, | |
711 | .. | |
712 | })) if !matches!( | |
713 | self_ty.span.ctxt().outer_expn_data().kind, | |
714 | ExpnKind::Macro(MacroKind::Derive, _) | |
715 | ) && !matches!( | |
716 | of_trait.as_ref().map(|t| t | |
717 | .path | |
718 | .span | |
719 | .ctxt() | |
720 | .outer_expn_data() | |
721 | .kind), | |
722 | Some(ExpnKind::Macro(MacroKind::Derive, _)) | |
723 | ) => | |
724 | { | |
725 | if let Some(pred) = parent_p { | |
726 | // Done to add the "doesn't satisfy" `span_label`. | |
727 | let _ = format_pred(*pred); | |
728 | } | |
729 | skip_list.insert(p); | |
730 | let mut spans = if cause_span != *item_span { | |
731 | let mut spans: MultiSpan = cause_span.into(); | |
732 | spans.push_span_label(cause_span, unsatisfied_msg); | |
733 | spans | |
734 | } else { | |
3c0e092e XL |
735 | let mut spans = Vec::with_capacity(2); |
736 | if let Some(trait_ref) = of_trait { | |
737 | spans.push(trait_ref.path.span); | |
738 | } | |
739 | spans.push(self_ty.span); | |
5e7ed085 FG |
740 | spans.into() |
741 | }; | |
742 | if let Some(trait_ref) = of_trait { | |
743 | spans.push_span_label(trait_ref.path.span, String::new()); | |
3c0e092e | 744 | } |
5e7ed085 FG |
745 | spans.push_span_label(self_ty.span, String::new()); |
746 | ||
923072b8 | 747 | let entry = spanned_predicates.entry(spans); |
5e7ed085 | 748 | entry.or_insert_with(|| (path, tr_self_ty, Vec::new())).2.push(p); |
3c0e092e | 749 | } |
5e7ed085 | 750 | _ => {} |
3c0e092e XL |
751 | } |
752 | } | |
5e7ed085 FG |
753 | let mut spanned_predicates: Vec<_> = spanned_predicates.into_iter().collect(); |
754 | spanned_predicates.sort_by_key(|(span, (_, _, _))| span.primary_span()); | |
755 | for (span, (_path, _self_ty, preds)) in spanned_predicates { | |
756 | let mut preds: Vec<_> = preds | |
757 | .into_iter() | |
758 | .filter_map(|pred| format_pred(*pred)) | |
759 | .map(|(p, _)| format!("`{}`", p)) | |
760 | .collect(); | |
761 | preds.sort(); | |
762 | preds.dedup(); | |
763 | let msg = if let [pred] = &preds[..] { | |
764 | format!("trait bound {} was not satisfied", pred) | |
765 | } else { | |
766 | format!( | |
767 | "the following trait bounds were not satisfied:\n{}", | |
768 | preds.join("\n"), | |
769 | ) | |
770 | }; | |
771 | err.span_note(span, &msg); | |
772 | unsatisfied_bounds = true; | |
3c0e092e XL |
773 | } |
774 | ||
775 | // The requirements that didn't have an `impl` span to show. | |
dfeec247 XL |
776 | let mut bound_list = unsatisfied_predicates |
777 | .iter() | |
3c0e092e XL |
778 | .filter_map(|(pred, parent_pred, _cause)| { |
779 | format_pred(*pred).map(|(p, self_ty)| { | |
5099ac24 | 780 | collect_type_param_suggestions(self_ty, *pred, &p); |
5e7ed085 FG |
781 | ( |
782 | match parent_pred { | |
3c0e092e | 783 | None => format!("`{}`", &p), |
5e7ed085 FG |
784 | Some(parent_pred) => match format_pred(*parent_pred) { |
785 | None => format!("`{}`", &p), | |
786 | Some((parent_p, _)) => { | |
787 | collect_type_param_suggestions( | |
788 | self_ty, | |
789 | *parent_pred, | |
790 | &p, | |
791 | ); | |
792 | format!( | |
793 | "`{}`\nwhich is required by `{}`", | |
794 | p, parent_p | |
795 | ) | |
796 | } | |
797 | }, | |
3c0e092e | 798 | }, |
5e7ed085 FG |
799 | *pred, |
800 | ) | |
74b04a01 XL |
801 | }) |
802 | }) | |
5e7ed085 FG |
803 | .filter(|(_, pred)| !skip_list.contains(&pred)) |
804 | .map(|(t, _)| t) | |
74b04a01 XL |
805 | .enumerate() |
806 | .collect::<Vec<(usize, String)>>(); | |
3c0e092e | 807 | |
923072b8 | 808 | for ((span, add_where_or_comma), obligations) in type_params.into_iter() { |
74b04a01 | 809 | restrict_type_params = true; |
3dfed10e XL |
810 | // #74886: Sort here so that the output is always the same. |
811 | let mut obligations = obligations.into_iter().collect::<Vec<_>>(); | |
812 | obligations.sort(); | |
74b04a01 XL |
813 | err.span_suggestion_verbose( |
814 | span, | |
815 | &format!( | |
816 | "consider restricting the type parameter{s} to satisfy the \ | |
817 | trait bound{s}", | |
818 | s = pluralize!(obligations.len()) | |
819 | ), | |
923072b8 | 820 | format!("{} {}", add_where_or_comma, obligations.join(", ")), |
74b04a01 XL |
821 | Applicability::MaybeIncorrect, |
822 | ); | |
823 | } | |
824 | ||
c295e0f8 | 825 | bound_list.sort_by(|(_, a), (_, b)| a.cmp(b)); // Sort alphabetically. |
74b04a01 XL |
826 | bound_list.dedup_by(|(_, a), (_, b)| a == b); // #35677 |
827 | bound_list.sort_by_key(|(pos, _)| *pos); // Keep the original predicate order. | |
5e7ed085 | 828 | |
3c0e092e | 829 | if !bound_list.is_empty() || !skip_list.is_empty() { |
74b04a01 XL |
830 | let bound_list = bound_list |
831 | .into_iter() | |
832 | .map(|(_, path)| path) | |
833 | .collect::<Vec<_>>() | |
834 | .join("\n"); | |
6a06907d | 835 | let actual_prefix = actual.prefix_string(self.tcx); |
5e7ed085 FG |
836 | info!("unimplemented_traits.len() == {}", unimplemented_traits.len()); |
837 | let (primary_message, label) = if unimplemented_traits.len() == 1 | |
838 | && unimplemented_traits_only | |
839 | { | |
840 | unimplemented_traits | |
841 | .into_iter() | |
842 | .next() | |
843 | .map(|(_, (trait_ref, obligation))| { | |
844 | if trait_ref.self_ty().references_error() | |
845 | || actual.references_error() | |
846 | { | |
847 | // Avoid crashing. | |
848 | return (None, None); | |
849 | } | |
850 | let OnUnimplementedNote { message, label, .. } = | |
851 | self.infcx.on_unimplemented_note(trait_ref, &obligation); | |
852 | (message, label) | |
853 | }) | |
854 | .unwrap_or((None, None)) | |
855 | } else { | |
856 | (None, None) | |
857 | }; | |
858 | let primary_message = primary_message.unwrap_or_else(|| format!( | |
5869c6ff XL |
859 | "the {item_kind} `{item_name}` exists for {actual_prefix} `{ty_str}`, but its trait bounds were not satisfied" |
860 | )); | |
5e7ed085 FG |
861 | err.set_primary_message(&primary_message); |
862 | if let Some(label) = label { | |
863 | custom_span_label = true; | |
864 | err.span_label(span, label); | |
865 | } | |
3c0e092e XL |
866 | if !bound_list.is_empty() { |
867 | err.note(&format!( | |
868 | "the following trait bounds were not satisfied:\n{bound_list}" | |
869 | )); | |
870 | } | |
c295e0f8 XL |
871 | self.suggest_derive(&mut err, &unsatisfied_predicates); |
872 | ||
cdc7bbd5 | 873 | unsatisfied_bounds = true; |
74b04a01 | 874 | } |
a7813a04 | 875 | } |
62682a34 | 876 | |
04454e1e | 877 | let label_span_not_found = |err: &mut DiagnosticBuilder<'_, _>| { |
5e7ed085 FG |
878 | if unsatisfied_predicates.is_empty() { |
879 | err.span_label(span, format!("{item_kind} not found in `{ty_str}`")); | |
880 | let is_string_or_ref_str = match actual.kind() { | |
881 | ty::Ref(_, ty, _) => { | |
882 | ty.is_str() | |
883 | || matches!( | |
884 | ty.kind(), | |
885 | ty::Adt(adt, _) if self.tcx.is_diagnostic_item(sym::String, adt.did()) | |
886 | ) | |
887 | } | |
888 | ty::Adt(adt, _) => self.tcx.is_diagnostic_item(sym::String, adt.did()), | |
889 | _ => false, | |
890 | }; | |
891 | if is_string_or_ref_str && item_name.name == sym::iter { | |
892 | err.span_suggestion_verbose( | |
893 | item_name.span, | |
894 | "because of the in-memory representation of `&str`, to obtain \ | |
895 | an `Iterator` over each of its codepoint use method `chars`", | |
923072b8 | 896 | "chars", |
5e7ed085 FG |
897 | Applicability::MachineApplicable, |
898 | ); | |
899 | } | |
900 | if let ty::Adt(adt, _) = rcvr_ty.kind() { | |
901 | let mut inherent_impls_candidate = self | |
902 | .tcx | |
903 | .inherent_impls(adt.did()) | |
904 | .iter() | |
905 | .copied() | |
906 | .filter(|def_id| { | |
907 | if let Some(assoc) = self.associated_value(*def_id, item_name) { | |
908 | // Check for both mode is the same so we avoid suggesting | |
909 | // incorrect associated item. | |
910 | match (mode, assoc.fn_has_self_parameter, source) { | |
911 | (Mode::MethodCall, true, SelfSource::MethodCall(_)) => { | |
912 | // We check that the suggest type is actually | |
913 | // different from the received one | |
914 | // So we avoid suggestion method with Box<Self> | |
915 | // for instance | |
916 | self.tcx.at(span).type_of(*def_id) != actual | |
917 | && self.tcx.at(span).type_of(*def_id) != rcvr_ty | |
918 | } | |
919 | (Mode::Path, false, _) => true, | |
920 | _ => false, | |
921 | } | |
922 | } else { | |
923 | false | |
924 | } | |
925 | }) | |
926 | .collect::<Vec<_>>(); | |
927 | if !inherent_impls_candidate.is_empty() { | |
928 | inherent_impls_candidate.sort(); | |
929 | inherent_impls_candidate.dedup(); | |
930 | ||
931 | // number of type to shows at most. | |
932 | let limit = if inherent_impls_candidate.len() == 5 { 5 } else { 4 }; | |
933 | let type_candidates = inherent_impls_candidate | |
934 | .iter() | |
935 | .take(limit) | |
936 | .map(|impl_item| { | |
937 | format!("- `{}`", self.tcx.at(span).type_of(*impl_item)) | |
938 | }) | |
939 | .collect::<Vec<_>>() | |
940 | .join("\n"); | |
941 | let additional_types = if inherent_impls_candidate.len() > limit { | |
942 | format!( | |
943 | "\nand {} more types", | |
944 | inherent_impls_candidate.len() - limit | |
945 | ) | |
946 | } else { | |
947 | "".to_string() | |
948 | }; | |
949 | err.note(&format!( | |
950 | "the {item_kind} was found for\n{}{}", | |
951 | type_candidates, additional_types | |
952 | )); | |
953 | } | |
954 | } | |
955 | } else { | |
956 | err.span_label(span, format!("{item_kind} cannot be called on `{ty_str}` due to unsatisfied trait bounds")); | |
957 | } | |
958 | }; | |
959 | ||
960 | // If the method name is the name of a field with a function or closure type, | |
961 | // give a helping note that it has to be called as `(x.f)(...)`. | |
962 | if let SelfSource::MethodCall(expr) = source { | |
04454e1e FG |
963 | if !self.suggest_field_call(span, rcvr_ty, expr, item_name, &mut err) |
964 | && lev_candidate.is_none() | |
965 | && !custom_span_label | |
966 | { | |
967 | label_span_not_found(&mut err); | |
968 | } | |
969 | } else if !custom_span_label { | |
970 | label_span_not_found(&mut err); | |
971 | } | |
5e7ed085 | 972 | |
923072b8 | 973 | self.check_for_field_method(&mut err, source, span, actual, item_name); |
5e7ed085 | 974 | |
923072b8 | 975 | self.check_for_unwrap_self(&mut err, source, span, actual, item_name); |
5e7ed085 FG |
976 | |
977 | bound_spans.sort(); | |
978 | bound_spans.dedup(); | |
979 | for (span, msg) in bound_spans.into_iter() { | |
980 | err.span_label(span, &msg); | |
981 | } | |
982 | ||
74b04a01 | 983 | if actual.is_numeric() && actual.is_fresh() || restrict_type_params { |
2c00a5a8 | 984 | } else { |
dfeec247 XL |
985 | self.suggest_traits_to_import( |
986 | &mut err, | |
987 | span, | |
988 | rcvr_ty, | |
989 | item_name, | |
990 | source, | |
991 | out_of_scope_traits, | |
74b04a01 | 992 | &unsatisfied_predicates, |
cdc7bbd5 | 993 | unsatisfied_bounds, |
dfeec247 | 994 | ); |
2c00a5a8 | 995 | } |
ea8adc8c | 996 | |
5869c6ff XL |
997 | // Don't emit a suggestion if we found an actual method |
998 | // that had unsatisfied trait bounds | |
999 | if unsatisfied_predicates.is_empty() && actual.is_enum() { | |
48663c56 XL |
1000 | let adt_def = actual.ty_adt_def().expect("enum is not an ADT"); |
1001 | if let Some(suggestion) = lev_distance::find_best_match_for_name( | |
5e7ed085 | 1002 | &adt_def.variants().iter().map(|s| s.name).collect::<Vec<_>>(), |
3dfed10e | 1003 | item_name.name, |
48663c56 XL |
1004 | None, |
1005 | ) { | |
1006 | err.span_suggestion( | |
1007 | span, | |
1008 | "there is a variant with a similar name", | |
923072b8 | 1009 | suggestion, |
48663c56 XL |
1010 | Applicability::MaybeIncorrect, |
1011 | ); | |
1012 | } | |
1013 | } | |
1014 | ||
3dfed10e | 1015 | if item_name.name == sym::as_str && actual.peel_refs().is_str() { |
a2a8927a XL |
1016 | let msg = "remove this method call"; |
1017 | let mut fallback_span = true; | |
e74abb32 | 1018 | if let SelfSource::MethodCall(expr) = source { |
dfeec247 XL |
1019 | let call_expr = |
1020 | self.tcx.hir().expect_expr(self.tcx.hir().get_parent_node(expr.hir_id)); | |
e74abb32 | 1021 | if let Some(span) = call_expr.span.trim_start(expr.span) { |
923072b8 | 1022 | err.span_suggestion(span, msg, "", Applicability::MachineApplicable); |
e74abb32 XL |
1023 | fallback_span = false; |
1024 | } | |
1025 | } | |
1026 | if fallback_span { | |
1027 | err.span_label(span, msg); | |
1028 | } | |
1029 | } else if let Some(lev_candidate) = lev_candidate { | |
5869c6ff XL |
1030 | // Don't emit a suggestion if we found an actual method |
1031 | // that had unsatisfied trait bounds | |
1032 | if unsatisfied_predicates.is_empty() { | |
1033 | let def_kind = lev_candidate.kind.as_def_kind(); | |
1034 | err.span_suggestion( | |
1035 | span, | |
1036 | &format!( | |
1037 | "there is {} {} with a similar name", | |
1038 | def_kind.article(), | |
1039 | def_kind.descr(lev_candidate.def_id), | |
1040 | ), | |
923072b8 | 1041 | lev_candidate.name, |
5869c6ff XL |
1042 | Applicability::MaybeIncorrect, |
1043 | ); | |
1044 | } | |
ea8adc8c | 1045 | } |
48663c56 | 1046 | |
e1599b0c | 1047 | return Some(err); |
a7813a04 | 1048 | } |
85aaf69f | 1049 | |
a7813a04 | 1050 | MethodError::Ambiguity(sources) => { |
dfeec247 XL |
1051 | let mut err = struct_span_err!( |
1052 | self.sess(), | |
ba9703b0 | 1053 | item_name.span, |
dfeec247 XL |
1054 | E0034, |
1055 | "multiple applicable items in scope" | |
1056 | ); | |
ba9703b0 | 1057 | err.span_label(item_name.span, format!("multiple `{}` found", item_name)); |
85aaf69f | 1058 | |
dfeec247 | 1059 | report_candidates(span, &mut err, sources, sugg_span); |
a7813a04 XL |
1060 | err.emit(); |
1061 | } | |
85aaf69f | 1062 | |
416331ca | 1063 | MethodError::PrivateMatch(kind, def_id, out_of_scope_traits) => { |
ba9703b0 | 1064 | let kind = kind.descr(def_id); |
dfeec247 XL |
1065 | let mut err = struct_span_err!( |
1066 | self.tcx.sess, | |
ba9703b0 | 1067 | item_name.span, |
dfeec247 XL |
1068 | E0624, |
1069 | "{} `{}` is private", | |
ba9703b0 | 1070 | kind, |
dfeec247 XL |
1071 | item_name |
1072 | ); | |
ba9703b0 | 1073 | err.span_label(item_name.span, &format!("private {}", kind)); |
136023e0 XL |
1074 | let sp = self |
1075 | .tcx | |
1076 | .hir() | |
1077 | .span_if_local(def_id) | |
1078 | .unwrap_or_else(|| self.tcx.def_span(def_id)); | |
1079 | err.span_label(sp, &format!("private {} defined here", kind)); | |
3b2f2976 XL |
1080 | self.suggest_valid_traits(&mut err, out_of_scope_traits); |
1081 | err.emit(); | |
a7813a04 | 1082 | } |
3b2f2976 | 1083 | |
74b04a01 | 1084 | MethodError::IllegalSizedBound(candidates, needs_mut, bound_span) => { |
3b2f2976 XL |
1085 | let msg = format!("the `{}` method cannot be invoked on a trait object", item_name); |
1086 | let mut err = self.sess().struct_span_err(span, &msg); | |
74b04a01 | 1087 | err.span_label(bound_span, "this has a `Sized` requirement"); |
3b2f2976 | 1088 | if !candidates.is_empty() { |
e74abb32 XL |
1089 | let help = format!( |
1090 | "{an}other candidate{s} {were} found in the following trait{s}, perhaps \ | |
1091 | add a `use` for {one_of_them}:", | |
dfeec247 | 1092 | an = if candidates.len() == 1 { "an" } else { "" }, |
60c5eb7d | 1093 | s = pluralize!(candidates.len()), |
e74abb32 | 1094 | were = if candidates.len() == 1 { "was" } else { "were" }, |
dfeec247 | 1095 | one_of_them = if candidates.len() == 1 { "it" } else { "one_of_them" }, |
e74abb32 | 1096 | ); |
3b2f2976 XL |
1097 | self.suggest_use_candidates(&mut err, help, candidates); |
1098 | } | |
1b1a35ee | 1099 | if let ty::Ref(region, t_type, mutability) = rcvr_ty.kind() { |
e74abb32 | 1100 | if needs_mut { |
dfeec247 | 1101 | let trait_type = self.tcx.mk_ref( |
5099ac24 FG |
1102 | *region, |
1103 | ty::TypeAndMut { ty: *t_type, mutbl: mutability.invert() }, | |
dfeec247 | 1104 | ); |
e74abb32 XL |
1105 | err.note(&format!("you need `{}` instead of `{}`", trait_type, rcvr_ty)); |
1106 | } | |
1107 | } | |
3b2f2976 XL |
1108 | err.emit(); |
1109 | } | |
ea8adc8c | 1110 | |
dfeec247 | 1111 | MethodError::BadReturnType => bug!("no return type expectations but got BadReturnType"), |
3b2f2976 | 1112 | } |
e1599b0c | 1113 | None |
3b2f2976 XL |
1114 | } |
1115 | ||
04454e1e FG |
1116 | fn suggest_field_call( |
1117 | &self, | |
1118 | span: Span, | |
1119 | rcvr_ty: Ty<'tcx>, | |
1120 | expr: &hir::Expr<'_>, | |
1121 | item_name: Ident, | |
1122 | err: &mut DiagnosticBuilder<'tcx, ErrorGuaranteed>, | |
1123 | ) -> bool { | |
1124 | let tcx = self.tcx; | |
1125 | let field_receiver = self.autoderef(span, rcvr_ty).find_map(|(ty, _)| match ty.kind() { | |
1126 | ty::Adt(def, substs) if !def.is_enum() => { | |
1127 | let variant = &def.non_enum_variant(); | |
1128 | tcx.find_field_index(item_name, variant).map(|index| { | |
1129 | let field = &variant.fields[index]; | |
1130 | let field_ty = field.ty(tcx, substs); | |
1131 | (field, field_ty) | |
1132 | }) | |
1133 | } | |
1134 | _ => None, | |
1135 | }); | |
1136 | if let Some((field, field_ty)) = field_receiver { | |
1137 | let scope = tcx.parent_module(self.body_id).to_def_id(); | |
1138 | let is_accessible = field.vis.is_accessible_from(scope, tcx); | |
1139 | ||
1140 | if is_accessible { | |
1141 | if self.is_fn_ty(field_ty, span) { | |
1142 | let expr_span = expr.span.to(item_name.span); | |
1143 | err.multipart_suggestion( | |
1144 | &format!( | |
1145 | "to call the function stored in `{}`, \ | |
1146 | surround the field access with parentheses", | |
1147 | item_name, | |
1148 | ), | |
1149 | vec![ | |
1150 | (expr_span.shrink_to_lo(), '('.to_string()), | |
1151 | (expr_span.shrink_to_hi(), ')'.to_string()), | |
1152 | ], | |
1153 | Applicability::MachineApplicable, | |
1154 | ); | |
1155 | } else { | |
1156 | let call_expr = tcx.hir().expect_expr(tcx.hir().get_parent_node(expr.hir_id)); | |
1157 | ||
1158 | if let Some(span) = call_expr.span.trim_start(item_name.span) { | |
1159 | err.span_suggestion( | |
1160 | span, | |
1161 | "remove the arguments", | |
923072b8 | 1162 | "", |
04454e1e FG |
1163 | Applicability::MaybeIncorrect, |
1164 | ); | |
1165 | } | |
1166 | } | |
1167 | } | |
1168 | ||
1169 | let field_kind = if is_accessible { "field" } else { "private field" }; | |
1170 | err.span_label(item_name.span, format!("{}, not a method", field_kind)); | |
1171 | return true; | |
1172 | } | |
1173 | false | |
1174 | } | |
1175 | ||
1176 | fn suggest_constraining_numerical_ty( | |
1177 | &self, | |
1178 | tcx: TyCtxt<'tcx>, | |
1179 | actual: Ty<'tcx>, | |
1180 | source: SelfSource<'_>, | |
1181 | span: Span, | |
1182 | item_kind: &str, | |
1183 | item_name: Ident, | |
1184 | ty_str: &str, | |
1185 | ) -> bool { | |
1186 | let found_candidate = all_traits(self.tcx) | |
1187 | .into_iter() | |
1188 | .any(|info| self.associated_value(info.def_id, item_name).is_some()); | |
1189 | let found_assoc = |ty: Ty<'tcx>| { | |
923072b8 | 1190 | simplify_type(tcx, ty, TreatParams::AsInfer) |
04454e1e FG |
1191 | .and_then(|simp| { |
1192 | tcx.incoherent_impls(simp) | |
1193 | .iter() | |
1194 | .find_map(|&id| self.associated_value(id, item_name)) | |
1195 | }) | |
1196 | .is_some() | |
1197 | }; | |
1198 | let found_candidate = found_candidate | |
1199 | || found_assoc(tcx.types.i8) | |
1200 | || found_assoc(tcx.types.i16) | |
1201 | || found_assoc(tcx.types.i32) | |
1202 | || found_assoc(tcx.types.i64) | |
1203 | || found_assoc(tcx.types.i128) | |
1204 | || found_assoc(tcx.types.u8) | |
1205 | || found_assoc(tcx.types.u16) | |
1206 | || found_assoc(tcx.types.u32) | |
1207 | || found_assoc(tcx.types.u64) | |
1208 | || found_assoc(tcx.types.u128) | |
1209 | || found_assoc(tcx.types.f32) | |
1210 | || found_assoc(tcx.types.f32); | |
1211 | if found_candidate | |
1212 | && actual.is_numeric() | |
1213 | && !actual.has_concrete_skeleton() | |
1214 | && let SelfSource::MethodCall(expr) = source | |
1215 | { | |
1216 | let mut err = struct_span_err!( | |
1217 | tcx.sess, | |
1218 | span, | |
1219 | E0689, | |
1220 | "can't call {} `{}` on ambiguous numeric type `{}`", | |
1221 | item_kind, | |
1222 | item_name, | |
1223 | ty_str | |
1224 | ); | |
1225 | let concrete_type = if actual.is_integral() { "i32" } else { "f32" }; | |
1226 | match expr.kind { | |
1227 | ExprKind::Lit(ref lit) => { | |
1228 | // numeric literal | |
1229 | let snippet = tcx | |
1230 | .sess | |
1231 | .source_map() | |
1232 | .span_to_snippet(lit.span) | |
1233 | .unwrap_or_else(|_| "<numeric literal>".to_owned()); | |
1234 | ||
1235 | // If this is a floating point literal that ends with '.', | |
1236 | // get rid of it to stop this from becoming a member access. | |
1237 | let snippet = snippet.strip_suffix('.').unwrap_or(&snippet); | |
1238 | ||
1239 | err.span_suggestion( | |
1240 | lit.span, | |
1241 | &format!( | |
1242 | "you must specify a concrete type for this numeric value, \ | |
1243 | like `{}`", | |
1244 | concrete_type | |
1245 | ), | |
1246 | format!("{snippet}_{concrete_type}"), | |
1247 | Applicability::MaybeIncorrect, | |
1248 | ); | |
1249 | } | |
1250 | ExprKind::Path(QPath::Resolved(_, path)) => { | |
1251 | // local binding | |
1252 | if let hir::def::Res::Local(hir_id) = path.res { | |
1253 | let span = tcx.hir().span(hir_id); | |
1254 | let snippet = tcx.sess.source_map().span_to_snippet(span); | |
1255 | let filename = tcx.sess.source_map().span_to_filename(span); | |
1256 | ||
1257 | let parent_node = | |
1258 | self.tcx.hir().get(self.tcx.hir().get_parent_node(hir_id)); | |
1259 | let msg = format!( | |
1260 | "you must specify a type for this binding, like `{}`", | |
1261 | concrete_type, | |
1262 | ); | |
1263 | ||
1264 | match (filename, parent_node, snippet) { | |
1265 | ( | |
1266 | FileName::Real(_), | |
1267 | Node::Local(hir::Local { | |
1268 | source: hir::LocalSource::Normal, | |
1269 | ty, | |
1270 | .. | |
1271 | }), | |
1272 | Ok(ref snippet), | |
1273 | ) => { | |
1274 | err.span_suggestion( | |
1275 | // account for `let x: _ = 42;` | |
1276 | // ^^^^ | |
1277 | span.to(ty.as_ref().map(|ty| ty.span).unwrap_or(span)), | |
1278 | &msg, | |
1279 | format!("{}: {}", snippet, concrete_type), | |
1280 | Applicability::MaybeIncorrect, | |
1281 | ); | |
1282 | } | |
1283 | _ => { | |
1284 | err.span_label(span, msg); | |
1285 | } | |
1286 | } | |
1287 | } | |
1288 | } | |
1289 | _ => {} | |
1290 | } | |
1291 | err.emit(); | |
1292 | return true; | |
1293 | } | |
1294 | false | |
1295 | } | |
1296 | ||
923072b8 FG |
1297 | fn check_for_field_method( |
1298 | &self, | |
1299 | err: &mut DiagnosticBuilder<'tcx, ErrorGuaranteed>, | |
1300 | source: SelfSource<'tcx>, | |
1301 | span: Span, | |
1302 | actual: Ty<'tcx>, | |
1303 | item_name: Ident, | |
1304 | ) { | |
1305 | if let SelfSource::MethodCall(expr) = source | |
1306 | && let Some((fields, substs)) = self.get_field_candidates(span, actual) | |
1307 | { | |
1308 | let call_expr = self.tcx.hir().expect_expr(self.tcx.hir().get_parent_node(expr.hir_id)); | |
1309 | for candidate_field in fields.iter() { | |
1310 | if let Some(field_path) = self.check_for_nested_field_satisfying( | |
1311 | span, | |
1312 | &|_, field_ty| { | |
1313 | self.lookup_probe( | |
1314 | span, | |
1315 | item_name, | |
1316 | field_ty, | |
1317 | call_expr, | |
1318 | ProbeScope::AllTraits, | |
1319 | ) | |
1320 | .is_ok() | |
1321 | }, | |
1322 | candidate_field, | |
1323 | substs, | |
1324 | vec![], | |
1325 | self.tcx.parent_module(expr.hir_id).to_def_id(), | |
1326 | ) { | |
1327 | let field_path_str = field_path | |
1328 | .iter() | |
1329 | .map(|id| id.name.to_ident_string()) | |
1330 | .collect::<Vec<String>>() | |
1331 | .join("."); | |
1332 | debug!("field_path_str: {:?}", field_path_str); | |
1333 | ||
1334 | err.span_suggestion_verbose( | |
1335 | item_name.span.shrink_to_lo(), | |
1336 | "one of the expressions' fields has a method of the same name", | |
1337 | format!("{field_path_str}."), | |
1338 | Applicability::MaybeIncorrect, | |
1339 | ); | |
1340 | } | |
1341 | } | |
1342 | } | |
1343 | } | |
1344 | ||
1345 | fn check_for_unwrap_self( | |
1346 | &self, | |
1347 | err: &mut DiagnosticBuilder<'tcx, ErrorGuaranteed>, | |
1348 | source: SelfSource<'tcx>, | |
1349 | span: Span, | |
1350 | actual: Ty<'tcx>, | |
1351 | item_name: Ident, | |
1352 | ) { | |
1353 | let tcx = self.tcx; | |
1354 | let SelfSource::MethodCall(expr) = source else { return; }; | |
1355 | let call_expr = tcx.hir().expect_expr(tcx.hir().get_parent_node(expr.hir_id)); | |
1356 | ||
1357 | let ty::Adt(kind, substs) = actual.kind() else { return; }; | |
1358 | if !kind.is_enum() { | |
1359 | return; | |
1360 | } | |
1361 | ||
1362 | let matching_variants: Vec<_> = kind | |
1363 | .variants() | |
1364 | .iter() | |
1365 | .flat_map(|variant| { | |
1366 | let [field] = &variant.fields[..] else { return None; }; | |
1367 | let field_ty = field.ty(tcx, substs); | |
1368 | ||
1369 | // Skip `_`, since that'll just lead to ambiguity. | |
1370 | if self.resolve_vars_if_possible(field_ty).is_ty_var() { | |
1371 | return None; | |
1372 | } | |
1373 | ||
1374 | self.lookup_probe(span, item_name, field_ty, call_expr, ProbeScope::AllTraits) | |
1375 | .ok() | |
1376 | .map(|pick| (variant, field, pick)) | |
1377 | }) | |
1378 | .collect(); | |
1379 | ||
1380 | let ret_ty_matches = |diagnostic_item| { | |
1381 | if let Some(ret_ty) = self | |
1382 | .ret_coercion | |
1383 | .as_ref() | |
1384 | .map(|c| self.resolve_vars_if_possible(c.borrow().expected_ty())) | |
1385 | && let ty::Adt(kind, _) = ret_ty.kind() | |
1386 | && tcx.get_diagnostic_item(diagnostic_item) == Some(kind.did()) | |
1387 | { | |
1388 | true | |
1389 | } else { | |
1390 | false | |
1391 | } | |
1392 | }; | |
1393 | ||
1394 | match &matching_variants[..] { | |
1395 | [(_, field, pick)] => { | |
1396 | let self_ty = field.ty(tcx, substs); | |
1397 | err.span_note( | |
1398 | tcx.def_span(pick.item.def_id), | |
1399 | &format!("the method `{item_name}` exists on the type `{self_ty}`"), | |
1400 | ); | |
1401 | let (article, kind, variant, question) = | |
1402 | if Some(kind.did()) == tcx.get_diagnostic_item(sym::Result) { | |
1403 | ("a", "Result", "Err", ret_ty_matches(sym::Result)) | |
1404 | } else if Some(kind.did()) == tcx.get_diagnostic_item(sym::Option) { | |
1405 | ("an", "Option", "None", ret_ty_matches(sym::Option)) | |
1406 | } else { | |
1407 | return; | |
1408 | }; | |
1409 | if question { | |
1410 | err.span_suggestion_verbose( | |
1411 | expr.span.shrink_to_hi(), | |
1412 | format!( | |
1413 | "use the `?` operator to extract the `{self_ty}` value, propagating \ | |
1414 | {article} `{kind}::{variant}` value to the caller" | |
1415 | ), | |
1416 | "?", | |
1417 | Applicability::MachineApplicable, | |
1418 | ); | |
1419 | } else { | |
1420 | err.span_suggestion_verbose( | |
1421 | expr.span.shrink_to_hi(), | |
1422 | format!( | |
1423 | "consider using `{kind}::expect` to unwrap the `{self_ty}` value, \ | |
1424 | panicking if the value is {article} `{kind}::{variant}`" | |
1425 | ), | |
1426 | ".expect(\"REASON\")", | |
1427 | Applicability::HasPlaceholders, | |
1428 | ); | |
1429 | } | |
1430 | } | |
1431 | // FIXME(compiler-errors): Support suggestions for other matching enum variants | |
1432 | _ => {} | |
1433 | } | |
1434 | } | |
1435 | ||
1436 | pub(crate) fn note_unmet_impls_on_type( | |
c295e0f8 | 1437 | &self, |
5e7ed085 | 1438 | err: &mut Diagnostic, |
c295e0f8 XL |
1439 | errors: Vec<FulfillmentError<'tcx>>, |
1440 | ) { | |
1441 | let all_local_types_needing_impls = | |
1442 | errors.iter().all(|e| match e.obligation.predicate.kind().skip_binder() { | |
1443 | ty::PredicateKind::Trait(pred) => match pred.self_ty().kind() { | |
5e7ed085 | 1444 | ty::Adt(def, _) => def.did().is_local(), |
c295e0f8 XL |
1445 | _ => false, |
1446 | }, | |
1447 | _ => false, | |
1448 | }); | |
1449 | let mut preds: Vec<_> = errors | |
1450 | .iter() | |
1451 | .filter_map(|e| match e.obligation.predicate.kind().skip_binder() { | |
1452 | ty::PredicateKind::Trait(pred) => Some(pred), | |
1453 | _ => None, | |
1454 | }) | |
1455 | .collect(); | |
1456 | preds.sort_by_key(|pred| (pred.def_id(), pred.self_ty())); | |
1457 | let def_ids = preds | |
1458 | .iter() | |
1459 | .filter_map(|pred| match pred.self_ty().kind() { | |
5e7ed085 | 1460 | ty::Adt(def, _) => Some(def.did()), |
c295e0f8 XL |
1461 | _ => None, |
1462 | }) | |
1463 | .collect::<FxHashSet<_>>(); | |
1464 | let sm = self.tcx.sess.source_map(); | |
1465 | let mut spans: MultiSpan = def_ids | |
1466 | .iter() | |
1467 | .filter_map(|def_id| { | |
1468 | let span = self.tcx.def_span(*def_id); | |
1469 | if span.is_dummy() { None } else { Some(sm.guess_head_span(span)) } | |
1470 | }) | |
1471 | .collect::<Vec<_>>() | |
1472 | .into(); | |
1473 | ||
1474 | for pred in &preds { | |
1475 | match pred.self_ty().kind() { | |
1476 | ty::Adt(def, _) => { | |
1477 | spans.push_span_label( | |
5e7ed085 | 1478 | sm.guess_head_span(self.tcx.def_span(def.did())), |
c295e0f8 XL |
1479 | format!("must implement `{}`", pred.trait_ref.print_only_trait_path()), |
1480 | ); | |
1481 | } | |
1482 | _ => {} | |
1483 | } | |
1484 | } | |
1485 | ||
1486 | if all_local_types_needing_impls && spans.primary_span().is_some() { | |
1487 | let msg = if preds.len() == 1 { | |
1488 | format!( | |
1489 | "an implementation of `{}` might be missing for `{}`", | |
1490 | preds[0].trait_ref.print_only_trait_path(), | |
1491 | preds[0].self_ty() | |
1492 | ) | |
1493 | } else { | |
1494 | format!( | |
1495 | "the following type{} would have to `impl` {} required trait{} for this \ | |
1496 | operation to be valid", | |
1497 | pluralize!(def_ids.len()), | |
1498 | if def_ids.len() == 1 { "its" } else { "their" }, | |
1499 | pluralize!(preds.len()), | |
1500 | ) | |
1501 | }; | |
1502 | err.span_note(spans, &msg); | |
1503 | } | |
1504 | ||
3c0e092e XL |
1505 | let preds: Vec<_> = errors |
1506 | .iter() | |
1507 | .map(|e| (e.obligation.predicate, None, Some(e.obligation.cause.clone()))) | |
1508 | .collect(); | |
c295e0f8 XL |
1509 | self.suggest_derive(err, &preds); |
1510 | } | |
1511 | ||
1512 | fn suggest_derive( | |
1513 | &self, | |
5e7ed085 | 1514 | err: &mut Diagnostic, |
a2a8927a | 1515 | unsatisfied_predicates: &[( |
3c0e092e XL |
1516 | ty::Predicate<'tcx>, |
1517 | Option<ty::Predicate<'tcx>>, | |
1518 | Option<ObligationCause<'tcx>>, | |
a2a8927a | 1519 | )], |
c295e0f8 XL |
1520 | ) { |
1521 | let mut derives = Vec::<(String, Span, String)>::new(); | |
1522 | let mut traits = Vec::<Span>::new(); | |
3c0e092e | 1523 | for (pred, _, _) in unsatisfied_predicates { |
5e7ed085 | 1524 | let ty::PredicateKind::Trait(trait_pred) = pred.kind().skip_binder() else { continue }; |
c295e0f8 | 1525 | let adt = match trait_pred.self_ty().ty_adt_def() { |
5e7ed085 | 1526 | Some(adt) if adt.did().is_local() => adt, |
c295e0f8 XL |
1527 | _ => continue, |
1528 | }; | |
5099ac24 FG |
1529 | if let Some(diagnostic_name) = self.tcx.get_diagnostic_name(trait_pred.def_id()) { |
1530 | let can_derive = match diagnostic_name { | |
1531 | sym::Default => !adt.is_enum(), | |
c295e0f8 XL |
1532 | sym::Eq |
1533 | | sym::PartialEq | |
1534 | | sym::Ord | |
1535 | | sym::PartialOrd | |
1536 | | sym::Clone | |
1537 | | sym::Copy | |
1538 | | sym::Hash | |
5099ac24 FG |
1539 | | sym::Debug => true, |
1540 | _ => false, | |
1541 | }; | |
1542 | if can_derive { | |
1543 | let self_name = trait_pred.self_ty().to_string(); | |
5e7ed085 | 1544 | let self_span = self.tcx.def_span(adt.did()); |
5099ac24 FG |
1545 | if let Some(poly_trait_ref) = pred.to_opt_poly_trait_pred() { |
1546 | for super_trait in supertraits(self.tcx, poly_trait_ref.to_poly_trait_ref()) | |
1547 | { | |
1548 | if let Some(parent_diagnostic_name) = | |
1549 | self.tcx.get_diagnostic_name(super_trait.def_id()) | |
1550 | { | |
1551 | derives.push(( | |
1552 | self_name.clone(), | |
923072b8 | 1553 | self_span, |
5099ac24 FG |
1554 | parent_diagnostic_name.to_string(), |
1555 | )); | |
1556 | } | |
1557 | } | |
1558 | } | |
1559 | derives.push((self_name, self_span, diagnostic_name.to_string())); | |
1560 | } else { | |
1561 | traits.push(self.tcx.def_span(trait_pred.def_id())); | |
1562 | } | |
c295e0f8 XL |
1563 | } else { |
1564 | traits.push(self.tcx.def_span(trait_pred.def_id())); | |
1565 | } | |
1566 | } | |
c295e0f8 XL |
1567 | traits.sort(); |
1568 | traits.dedup(); | |
1569 | ||
a2a8927a XL |
1570 | derives.sort(); |
1571 | derives.dedup(); | |
1572 | ||
1573 | let mut derives_grouped = Vec::<(String, Span, String)>::new(); | |
1574 | for (self_name, self_span, trait_name) in derives.into_iter() { | |
1575 | if let Some((last_self_name, _, ref mut last_trait_names)) = derives_grouped.last_mut() | |
1576 | { | |
1577 | if last_self_name == &self_name { | |
1578 | last_trait_names.push_str(format!(", {}", trait_name).as_str()); | |
1579 | continue; | |
1580 | } | |
1581 | } | |
1582 | derives_grouped.push((self_name, self_span, trait_name)); | |
1583 | } | |
1584 | ||
c295e0f8 XL |
1585 | let len = traits.len(); |
1586 | if len > 0 { | |
1587 | let span: MultiSpan = traits.into(); | |
1588 | err.span_note( | |
1589 | span, | |
1590 | &format!("the following trait{} must be implemented", pluralize!(len),), | |
1591 | ); | |
1592 | } | |
1593 | ||
1594 | for (self_name, self_span, traits) in &derives_grouped { | |
1595 | err.span_suggestion_verbose( | |
1596 | self_span.shrink_to_lo(), | |
1597 | &format!("consider annotating `{}` with `#[derive({})]`", self_name, traits), | |
1598 | format!("#[derive({})]\n", traits), | |
1599 | Applicability::MaybeIncorrect, | |
1600 | ); | |
1601 | } | |
1602 | } | |
1603 | ||
e74abb32 XL |
1604 | /// Print out the type for use in value namespace. |
1605 | fn ty_to_value_string(&self, ty: Ty<'tcx>) -> String { | |
1b1a35ee | 1606 | match ty.kind() { |
5e7ed085 | 1607 | ty::Adt(def, substs) => format!("{}", ty::Instance::new(def.did(), substs)), |
e74abb32 XL |
1608 | _ => self.ty_to_string(ty), |
1609 | } | |
1610 | } | |
1611 | ||
1b1a35ee XL |
1612 | fn suggest_await_before_method( |
1613 | &self, | |
5e7ed085 | 1614 | err: &mut Diagnostic, |
1b1a35ee XL |
1615 | item_name: Ident, |
1616 | ty: Ty<'tcx>, | |
1617 | call: &hir::Expr<'_>, | |
1618 | span: Span, | |
1619 | ) { | |
29967ef6 | 1620 | let output_ty = match self.infcx.get_impl_future_output_ty(ty) { |
5099ac24 | 1621 | Some(output_ty) => self.resolve_vars_if_possible(output_ty).skip_binder(), |
29967ef6 XL |
1622 | _ => return, |
1623 | }; | |
1624 | let method_exists = self.method_exists(item_name, output_ty, call.hir_id, true); | |
1625 | debug!("suggest_await_before_method: is_method_exist={}", method_exists); | |
1626 | if method_exists { | |
1627 | err.span_suggestion_verbose( | |
1628 | span.shrink_to_lo(), | |
1629 | "consider `await`ing on the `Future` and calling the method on its `Output`", | |
923072b8 | 1630 | "await.", |
29967ef6 XL |
1631 | Applicability::MaybeIncorrect, |
1632 | ); | |
1b1a35ee XL |
1633 | } |
1634 | } | |
1635 | ||
04454e1e | 1636 | fn suggest_use_candidates(&self, err: &mut Diagnostic, msg: String, candidates: Vec<DefId>) { |
a2a8927a XL |
1637 | let parent_map = self.tcx.visible_parent_map(()); |
1638 | ||
1639 | // Separate out candidates that must be imported with a glob, because they are named `_` | |
1640 | // and cannot be referred with their identifier. | |
1641 | let (candidates, globs): (Vec<_>, Vec<_>) = candidates.into_iter().partition(|trait_did| { | |
1642 | if let Some(parent_did) = parent_map.get(trait_did) { | |
1643 | // If the item is re-exported as `_`, we should suggest a glob-import instead. | |
04454e1e | 1644 | if *parent_did != self.tcx.parent(*trait_did) |
a2a8927a XL |
1645 | && self |
1646 | .tcx | |
5099ac24 | 1647 | .module_children(*parent_did) |
a2a8927a XL |
1648 | .iter() |
1649 | .filter(|child| child.res.opt_def_id() == Some(*trait_did)) | |
1650 | .all(|child| child.ident.name == kw::Underscore) | |
1651 | { | |
1652 | return false; | |
1653 | } | |
1654 | } | |
1655 | ||
1656 | true | |
1657 | }); | |
1658 | ||
74b04a01 | 1659 | let module_did = self.tcx.parent_module(self.body_id); |
04454e1e FG |
1660 | let (module, _, _) = self.tcx.hir().get_module(module_did); |
1661 | let span = module.spans.inject_use_span; | |
ff7c6d11 | 1662 | |
04454e1e FG |
1663 | let path_strings = candidates.iter().map(|trait_did| { |
1664 | format!("use {};\n", with_crate_prefix!(self.tcx.def_path_str(*trait_did)),) | |
1665 | }); | |
a2a8927a | 1666 | |
04454e1e FG |
1667 | let glob_path_strings = globs.iter().map(|trait_did| { |
1668 | let parent_did = parent_map.get(trait_did).unwrap(); | |
1669 | format!( | |
1670 | "use {}::*; // trait {}\n", | |
1671 | with_crate_prefix!(self.tcx.def_path_str(*parent_did)), | |
1672 | self.tcx.item_name(*trait_did), | |
1673 | ) | |
1674 | }); | |
a2a8927a | 1675 | |
04454e1e FG |
1676 | err.span_suggestions( |
1677 | span, | |
1678 | &msg, | |
1679 | path_strings.chain(glob_path_strings), | |
1680 | Applicability::MaybeIncorrect, | |
1681 | ); | |
3b2f2976 XL |
1682 | } |
1683 | ||
e74abb32 XL |
1684 | fn suggest_valid_traits( |
1685 | &self, | |
5e7ed085 | 1686 | err: &mut Diagnostic, |
e74abb32 XL |
1687 | valid_out_of_scope_traits: Vec<DefId>, |
1688 | ) -> bool { | |
3b2f2976 XL |
1689 | if !valid_out_of_scope_traits.is_empty() { |
1690 | let mut candidates = valid_out_of_scope_traits; | |
1691 | candidates.sort(); | |
1692 | candidates.dedup(); | |
3c0e092e XL |
1693 | |
1694 | // `TryFrom` and `FromIterator` have no methods | |
1695 | let edition_fix = candidates | |
1696 | .iter() | |
1697 | .find(|did| self.tcx.is_diagnostic_item(sym::TryInto, **did)) | |
1698 | .copied(); | |
1699 | ||
3b2f2976 | 1700 | err.help("items from traits can only be used if the trait is in scope"); |
e74abb32 XL |
1701 | let msg = format!( |
1702 | "the following {traits_are} implemented but not in scope; \ | |
1703 | perhaps add a `use` for {one_of_them}:", | |
dfeec247 XL |
1704 | traits_are = if candidates.len() == 1 { "trait is" } else { "traits are" }, |
1705 | one_of_them = if candidates.len() == 1 { "it" } else { "one of them" }, | |
e74abb32 | 1706 | ); |
3b2f2976 XL |
1707 | |
1708 | self.suggest_use_candidates(err, msg, candidates); | |
3c0e092e XL |
1709 | if let Some(did) = edition_fix { |
1710 | err.note(&format!( | |
1711 | "'{}' is included in the prelude starting in Edition 2021", | |
5e7ed085 | 1712 | with_crate_prefix!(self.tcx.def_path_str(did)) |
3c0e092e XL |
1713 | )); |
1714 | } | |
1715 | ||
3b2f2976 XL |
1716 | true |
1717 | } else { | |
1718 | false | |
54a0048b | 1719 | } |
85aaf69f SL |
1720 | } |
1721 | ||
cdc7bbd5 | 1722 | fn suggest_traits_to_import( |
416331ca | 1723 | &self, |
5e7ed085 | 1724 | err: &mut Diagnostic, |
416331ca XL |
1725 | span: Span, |
1726 | rcvr_ty: Ty<'tcx>, | |
f9f354fc | 1727 | item_name: Ident, |
cdc7bbd5 | 1728 | source: SelfSource<'tcx>, |
416331ca | 1729 | valid_out_of_scope_traits: Vec<DefId>, |
3c0e092e XL |
1730 | unsatisfied_predicates: &[( |
1731 | ty::Predicate<'tcx>, | |
1732 | Option<ty::Predicate<'tcx>>, | |
1733 | Option<ObligationCause<'tcx>>, | |
1734 | )], | |
cdc7bbd5 | 1735 | unsatisfied_bounds: bool, |
416331ca | 1736 | ) { |
cdc7bbd5 XL |
1737 | let mut alt_rcvr_sugg = false; |
1738 | if let (SelfSource::MethodCall(rcvr), false) = (source, unsatisfied_bounds) { | |
1739 | debug!(?span, ?item_name, ?rcvr_ty, ?rcvr); | |
1740 | let skippable = [ | |
1741 | self.tcx.lang_items().clone_trait(), | |
1742 | self.tcx.lang_items().deref_trait(), | |
1743 | self.tcx.lang_items().deref_mut_trait(), | |
1744 | self.tcx.lang_items().drop_trait(), | |
3c0e092e | 1745 | self.tcx.get_diagnostic_item(sym::AsRef), |
cdc7bbd5 XL |
1746 | ]; |
1747 | // Try alternative arbitrary self types that could fulfill this call. | |
1748 | // FIXME: probe for all types that *could* be arbitrary self-types, not | |
1749 | // just this list. | |
1750 | for (rcvr_ty, post) in &[ | |
1751 | (rcvr_ty, ""), | |
5099ac24 FG |
1752 | (self.tcx.mk_mut_ref(self.tcx.lifetimes.re_erased, rcvr_ty), "&mut "), |
1753 | (self.tcx.mk_imm_ref(self.tcx.lifetimes.re_erased, rcvr_ty), "&"), | |
cdc7bbd5 | 1754 | ] { |
923072b8 | 1755 | match self.lookup_probe(span, item_name, *rcvr_ty, rcvr, ProbeScope::AllTraits) { |
5e7ed085 FG |
1756 | Ok(pick) => { |
1757 | // If the method is defined for the receiver we have, it likely wasn't `use`d. | |
1758 | // We point at the method, but we just skip the rest of the check for arbitrary | |
1759 | // self types and rely on the suggestion to `use` the trait from | |
1760 | // `suggest_valid_traits`. | |
1761 | let did = Some(pick.item.container.id()); | |
1762 | let skip = skippable.contains(&did); | |
1763 | if pick.autoderefs == 0 && !skip { | |
1764 | err.span_label( | |
1765 | pick.item.ident(self.tcx).span, | |
1766 | &format!("the method is available for `{}` here", rcvr_ty), | |
1767 | ); | |
1768 | } | |
1769 | break; | |
cdc7bbd5 | 1770 | } |
5e7ed085 FG |
1771 | Err(MethodError::Ambiguity(_)) => { |
1772 | // If the method is defined (but ambiguous) for the receiver we have, it is also | |
1773 | // likely we haven't `use`d it. It may be possible that if we `Box`/`Pin`/etc. | |
1774 | // the receiver, then it might disambiguate this method, but I think these | |
1775 | // suggestions are generally misleading (see #94218). | |
1776 | break; | |
1777 | } | |
1778 | _ => {} | |
cdc7bbd5 | 1779 | } |
5e7ed085 | 1780 | |
cdc7bbd5 | 1781 | for (rcvr_ty, pre) in &[ |
5099ac24 FG |
1782 | (self.tcx.mk_lang_item(*rcvr_ty, LangItem::OwnedBox), "Box::new"), |
1783 | (self.tcx.mk_lang_item(*rcvr_ty, LangItem::Pin), "Pin::new"), | |
1784 | (self.tcx.mk_diagnostic_item(*rcvr_ty, sym::Arc), "Arc::new"), | |
1785 | (self.tcx.mk_diagnostic_item(*rcvr_ty, sym::Rc), "Rc::new"), | |
cdc7bbd5 | 1786 | ] { |
923072b8 FG |
1787 | if let Some(new_rcvr_t) = *rcvr_ty |
1788 | && let Ok(pick) = self.lookup_probe( | |
1789 | span, | |
1790 | item_name, | |
1791 | new_rcvr_t, | |
1792 | rcvr, | |
1793 | ProbeScope::AllTraits, | |
1794 | ) | |
1795 | { | |
5e7ed085 FG |
1796 | debug!("try_alt_rcvr: pick candidate {:?}", pick); |
1797 | let did = Some(pick.item.container.id()); | |
1798 | // We don't want to suggest a container type when the missing | |
1799 | // method is `.clone()` or `.deref()` otherwise we'd suggest | |
1800 | // `Arc::new(foo).clone()`, which is far from what the user wants. | |
1801 | // Explicitly ignore the `Pin::as_ref()` method as `Pin` does not | |
1802 | // implement the `AsRef` trait. | |
1803 | let skip = skippable.contains(&did) | |
1804 | || (("Pin::new" == *pre) && (sym::as_ref == item_name.name)); | |
1805 | // Make sure the method is defined for the *actual* receiver: we don't | |
1806 | // want to treat `Box<Self>` as a receiver if it only works because of | |
1807 | // an autoderef to `&self` | |
1808 | if pick.autoderefs == 0 && !skip { | |
1809 | err.span_label( | |
1810 | pick.item.ident(self.tcx).span, | |
1811 | &format!("the method is available for `{}` here", new_rcvr_t), | |
1812 | ); | |
1813 | err.multipart_suggestion( | |
1814 | "consider wrapping the receiver expression with the \ | |
1815 | appropriate type", | |
1816 | vec![ | |
1817 | (rcvr.span.shrink_to_lo(), format!("{}({}", pre, post)), | |
1818 | (rcvr.span.shrink_to_hi(), ")".to_string()), | |
1819 | ], | |
1820 | Applicability::MaybeIncorrect, | |
1821 | ); | |
1822 | // We don't care about the other suggestions. | |
1823 | alt_rcvr_sugg = true; | |
cdc7bbd5 XL |
1824 | } |
1825 | } | |
1826 | } | |
1827 | } | |
1828 | } | |
3b2f2976 | 1829 | if self.suggest_valid_traits(err, valid_out_of_scope_traits) { |
c30ab7b3 | 1830 | return; |
85aaf69f | 1831 | } |
85aaf69f | 1832 | |
0731742a | 1833 | let type_is_local = self.type_derefs_to_local(span, rcvr_ty, source); |
a7813a04 | 1834 | |
74b04a01 | 1835 | let mut arbitrary_rcvr = vec![]; |
0731742a | 1836 | // There are no traits implemented, so lets suggest some traits to |
a7813a04 XL |
1837 | // implement, by finding ones that have the item name, and are |
1838 | // legal to implement. | |
8bb4bdeb | 1839 | let mut candidates = all_traits(self.tcx) |
83c7162d | 1840 | .into_iter() |
3dfed10e XL |
1841 | // Don't issue suggestions for unstable traits since they're |
1842 | // unlikely to be implementable anyway | |
1843 | .filter(|info| match self.tcx.lookup_stability(info.def_id) { | |
1844 | Some(attr) => attr.level.is_stable(), | |
1845 | None => true, | |
1846 | }) | |
a7813a04 | 1847 | .filter(|info| { |
0731742a | 1848 | // We approximate the coherence rules to only suggest |
a7813a04 | 1849 | // traits that are legal to implement by requiring that |
0731742a | 1850 | // either the type or trait is local. Multi-dispatch means |
a7813a04 XL |
1851 | // this isn't perfect (that is, there are cases when |
1852 | // implementing a trait would be legal but is rejected | |
1853 | // here). | |
3c0e092e | 1854 | unsatisfied_predicates.iter().all(|(p, _, _)| { |
5869c6ff | 1855 | match p.kind().skip_binder() { |
3dfed10e XL |
1856 | // Hide traits if they are present in predicates as they can be fixed without |
1857 | // having to implement them. | |
94222f64 | 1858 | ty::PredicateKind::Trait(t) => t.def_id() == info.def_id, |
5869c6ff | 1859 | ty::PredicateKind::Projection(p) => { |
3dfed10e XL |
1860 | p.projection_ty.item_def_id == info.def_id |
1861 | } | |
1862 | _ => false, | |
1863 | } | |
74b04a01 | 1864 | }) && (type_is_local || info.def_id.is_local()) |
dfeec247 | 1865 | && self |
5099ac24 | 1866 | .associated_value(info.def_id, item_name) |
2c00a5a8 | 1867 | .filter(|item| { |
ba9703b0 | 1868 | if let ty::AssocKind::Fn = item.kind { |
f9f354fc XL |
1869 | let id = item |
1870 | .def_id | |
1871 | .as_local() | |
3dfed10e | 1872 | .map(|def_id| self.tcx.hir().local_def_id_to_hir_id(def_id)); |
74b04a01 | 1873 | if let Some(hir::Node::TraitItem(hir::TraitItem { |
ba9703b0 | 1874 | kind: hir::TraitItemKind::Fn(fn_sig, method), |
74b04a01 XL |
1875 | .. |
1876 | })) = id.map(|id| self.tcx.hir().get(id)) | |
1877 | { | |
1878 | let self_first_arg = match method { | |
ba9703b0 | 1879 | hir::TraitFn::Required([ident, ..]) => { |
74b04a01 XL |
1880 | ident.name == kw::SelfLower |
1881 | } | |
ba9703b0 | 1882 | hir::TraitFn::Provided(body_id) => { |
f9f354fc XL |
1883 | self.tcx.hir().body(*body_id).params.first().map_or( |
1884 | false, | |
1885 | |param| { | |
1886 | matches!( | |
1887 | param.pat.kind, | |
1888 | hir::PatKind::Binding(_, _, ident, _) | |
1889 | if ident.name == kw::SelfLower | |
1890 | ) | |
1891 | }, | |
1892 | ) | |
74b04a01 XL |
1893 | } |
1894 | _ => false, | |
1895 | }; | |
1896 | ||
1897 | if !fn_sig.decl.implicit_self.has_implicit_self() | |
1898 | && self_first_arg | |
1899 | { | |
1900 | if let Some(ty) = fn_sig.decl.inputs.get(0) { | |
1901 | arbitrary_rcvr.push(ty.span); | |
1902 | } | |
1903 | return false; | |
1904 | } | |
1905 | } | |
1906 | } | |
2c00a5a8 | 1907 | // We only want to suggest public or local traits (#45781). |
3c0e092e | 1908 | item.vis.is_public() || info.def_id.is_local() |
2c00a5a8 XL |
1909 | }) |
1910 | .is_some() | |
a7813a04 XL |
1911 | }) |
1912 | .collect::<Vec<_>>(); | |
74b04a01 XL |
1913 | for span in &arbitrary_rcvr { |
1914 | err.span_label( | |
1915 | *span, | |
1916 | "the method might not be found because of this arbitrary self type", | |
1917 | ); | |
1918 | } | |
cdc7bbd5 XL |
1919 | if alt_rcvr_sugg { |
1920 | return; | |
1921 | } | |
a7813a04 XL |
1922 | |
1923 | if !candidates.is_empty() { | |
0731742a | 1924 | // Sort from most relevant to least relevant. |
a7813a04 XL |
1925 | candidates.sort_by(|a, b| a.cmp(b).reverse()); |
1926 | candidates.dedup(); | |
1927 | ||
1b1a35ee | 1928 | let param_type = match rcvr_ty.kind() { |
416331ca | 1929 | ty::Param(param) => Some(param), |
1b1a35ee | 1930 | ty::Ref(_, ty, _) => match ty.kind() { |
416331ca XL |
1931 | ty::Param(param) => Some(param), |
1932 | _ => None, | |
dfeec247 | 1933 | }, |
416331ca XL |
1934 | _ => None, |
1935 | }; | |
1936 | err.help(if param_type.is_some() { | |
1937 | "items from traits can only be used if the type parameter is bounded by the trait" | |
1938 | } else { | |
1939 | "items from traits can only be used if the trait is implemented and in scope" | |
1940 | }); | |
fc512014 | 1941 | let candidates_len = candidates.len(); |
dfeec247 XL |
1942 | let message = |action| { |
1943 | format!( | |
1944 | "the following {traits_define} an item `{name}`, perhaps you need to {action} \ | |
74b04a01 | 1945 | {one_of_them}:", |
dfeec247 | 1946 | traits_define = |
fc512014 | 1947 | if candidates_len == 1 { "trait defines" } else { "traits define" }, |
dfeec247 | 1948 | action = action, |
fc512014 | 1949 | one_of_them = if candidates_len == 1 { "it" } else { "one of them" }, |
dfeec247 XL |
1950 | name = item_name, |
1951 | ) | |
1952 | }; | |
416331ca | 1953 | // Obtain the span for `param` and use it for a structured suggestion. |
c295e0f8 | 1954 | if let (Some(param), Some(table)) = (param_type, self.in_progress_typeck_results) { |
ba9703b0 | 1955 | let table_owner = table.borrow().hir_owner; |
f035d41b XL |
1956 | let generics = self.tcx.generics_of(table_owner.to_def_id()); |
1957 | let type_param = generics.type_param(param, self.tcx); | |
5099ac24 | 1958 | let hir = self.tcx.hir(); |
f035d41b | 1959 | if let Some(def_id) = type_param.def_id.as_local() { |
3dfed10e | 1960 | let id = hir.local_def_id_to_hir_id(def_id); |
f035d41b XL |
1961 | // Get the `hir::Param` to verify whether it already has any bounds. |
1962 | // We do this to avoid suggesting code that ends up as `T: FooBar`, | |
1963 | // instead we suggest `T: Foo + Bar` in that case. | |
1964 | match hir.get(id) { | |
c295e0f8 | 1965 | Node::GenericParam(param) => { |
04454e1e FG |
1966 | enum Introducer { |
1967 | Plus, | |
1968 | Colon, | |
1969 | Nothing, | |
1970 | } | |
1971 | let ast_generics = hir.get_generics(id.owner).unwrap(); | |
1972 | let (sp, mut introducer) = if let Some(span) = | |
1973 | ast_generics.bounds_span_for_suggestions(def_id) | |
1974 | { | |
1975 | (span, Introducer::Plus) | |
1976 | } else if let Some(colon_span) = param.colon_span { | |
1977 | (colon_span.shrink_to_hi(), Introducer::Nothing) | |
f035d41b | 1978 | } else { |
04454e1e | 1979 | (param.span.shrink_to_hi(), Introducer::Colon) |
f035d41b | 1980 | }; |
04454e1e FG |
1981 | if matches!( |
1982 | param.kind, | |
1983 | hir::GenericParamKind::Type { synthetic: true, .. }, | |
1984 | ) { | |
1985 | introducer = Introducer::Plus | |
1986 | } | |
1987 | let trait_def_ids: FxHashSet<DefId> = ast_generics | |
1988 | .bounds_for_param(def_id) | |
1989 | .flat_map(|bp| bp.bounds.iter()) | |
6a06907d | 1990 | .filter_map(|bound| bound.trait_ref()?.trait_def_id()) |
f035d41b XL |
1991 | .collect(); |
1992 | if !candidates.iter().any(|t| trait_def_ids.contains(&t.def_id)) { | |
e74abb32 XL |
1993 | err.span_suggestions( |
1994 | sp, | |
f035d41b XL |
1995 | &message(format!( |
1996 | "restrict type parameter `{}` with", | |
1997 | param.name.ident(), | |
1998 | )), | |
dfeec247 | 1999 | candidates.iter().map(|t| { |
f035d41b | 2000 | format!( |
04454e1e FG |
2001 | "{} {}", |
2002 | match introducer { | |
2003 | Introducer::Plus => " +", | |
2004 | Introducer::Colon => ":", | |
2005 | Introducer::Nothing => "", | |
2006 | }, | |
f035d41b | 2007 | self.tcx.def_path_str(t.def_id), |
f035d41b | 2008 | ) |
dfeec247 | 2009 | }), |
e74abb32 XL |
2010 | Applicability::MaybeIncorrect, |
2011 | ); | |
e1599b0c | 2012 | } |
fc512014 | 2013 | return; |
f035d41b XL |
2014 | } |
2015 | Node::Item(hir::Item { | |
2016 | kind: hir::ItemKind::Trait(.., bounds, _), | |
2017 | ident, | |
2018 | .. | |
2019 | }) => { | |
2020 | let (sp, sep, article) = if bounds.is_empty() { | |
2021 | (ident.span.shrink_to_hi(), ":", "a") | |
2022 | } else { | |
2023 | (bounds.last().unwrap().span().shrink_to_hi(), " +", "another") | |
2024 | }; | |
2025 | err.span_suggestions( | |
2026 | sp, | |
2027 | &message(format!("add {} supertrait for", article)), | |
2028 | candidates.iter().map(|t| { | |
2029 | format!("{} {}", sep, self.tcx.def_path_str(t.def_id),) | |
2030 | }), | |
2031 | Applicability::MaybeIncorrect, | |
2032 | ); | |
fc512014 | 2033 | return; |
416331ca | 2034 | } |
f035d41b | 2035 | _ => {} |
416331ca | 2036 | } |
f035d41b | 2037 | } |
416331ca XL |
2038 | } |
2039 | ||
fc512014 XL |
2040 | let (potential_candidates, explicitly_negative) = if param_type.is_some() { |
2041 | // FIXME: Even though negative bounds are not implemented, we could maybe handle | |
2042 | // cases where a positive bound implies a negative impl. | |
2043 | (candidates, Vec::new()) | |
5e7ed085 | 2044 | } else if let Some(simp_rcvr_ty) = |
923072b8 | 2045 | simplify_type(self.tcx, rcvr_ty, TreatParams::AsPlaceholder) |
a2a8927a | 2046 | { |
fc512014 XL |
2047 | let mut potential_candidates = Vec::new(); |
2048 | let mut explicitly_negative = Vec::new(); | |
2049 | for candidate in candidates { | |
2050 | // Check if there's a negative impl of `candidate` for `rcvr_ty` | |
2051 | if self | |
2052 | .tcx | |
2053 | .all_impls(candidate.def_id) | |
2054 | .filter(|imp_did| { | |
2055 | self.tcx.impl_polarity(*imp_did) == ty::ImplPolarity::Negative | |
2056 | }) | |
2057 | .any(|imp_did| { | |
2058 | let imp = self.tcx.impl_trait_ref(imp_did).unwrap(); | |
5099ac24 | 2059 | let imp_simp = |
923072b8 | 2060 | simplify_type(self.tcx, imp.self_ty(), TreatParams::AsPlaceholder); |
5869c6ff | 2061 | imp_simp.map_or(false, |s| s == simp_rcvr_ty) |
fc512014 XL |
2062 | }) |
2063 | { | |
2064 | explicitly_negative.push(candidate); | |
2065 | } else { | |
2066 | potential_candidates.push(candidate); | |
74b04a01 XL |
2067 | } |
2068 | } | |
fc512014 XL |
2069 | (potential_candidates, explicitly_negative) |
2070 | } else { | |
2071 | // We don't know enough about `recv_ty` to make proper suggestions. | |
2072 | (candidates, Vec::new()) | |
2073 | }; | |
2074 | ||
2075 | let action = if let Some(param) = param_type { | |
2076 | format!("restrict type parameter `{}` with", param) | |
2077 | } else { | |
2078 | // FIXME: it might only need to be imported into scope, not implemented. | |
2079 | "implement".to_string() | |
2080 | }; | |
2081 | match &potential_candidates[..] { | |
2082 | [] => {} | |
2083 | [trait_info] if trait_info.def_id.is_local() => { | |
2084 | let span = self.tcx.hir().span_if_local(trait_info.def_id).unwrap(); | |
2085 | err.span_note( | |
2086 | self.tcx.sess.source_map().guess_head_span(span), | |
2087 | &format!( | |
2088 | "`{}` defines an item `{}`, perhaps you need to {} it", | |
2089 | self.tcx.def_path_str(trait_info.def_id), | |
2090 | item_name, | |
2091 | action | |
2092 | ), | |
2093 | ); | |
2094 | } | |
2095 | trait_infos => { | |
74b04a01 | 2096 | let mut msg = message(action); |
fc512014 | 2097 | for (i, trait_info) in trait_infos.iter().enumerate() { |
74b04a01 XL |
2098 | msg.push_str(&format!( |
2099 | "\ncandidate #{}: `{}`", | |
2100 | i + 1, | |
2101 | self.tcx.def_path_str(trait_info.def_id), | |
2102 | )); | |
2103 | } | |
fc512014 XL |
2104 | err.note(&msg); |
2105 | } | |
2106 | } | |
2107 | match &explicitly_negative[..] { | |
2108 | [] => {} | |
2109 | [trait_info] => { | |
2110 | let msg = format!( | |
5099ac24 | 2111 | "the trait `{}` defines an item `{}`, but is explicitly unimplemented", |
fc512014 XL |
2112 | self.tcx.def_path_str(trait_info.def_id), |
2113 | item_name | |
2114 | ); | |
2115 | err.note(&msg); | |
2116 | } | |
2117 | trait_infos => { | |
2118 | let mut msg = format!( | |
5099ac24 | 2119 | "the following traits define an item `{}`, but are explicitly unimplemented:", |
fc512014 XL |
2120 | item_name |
2121 | ); | |
2122 | for trait_info in trait_infos { | |
2123 | msg.push_str(&format!("\n{}", self.tcx.def_path_str(trait_info.def_id))); | |
2124 | } | |
2125 | err.note(&msg); | |
416331ca | 2126 | } |
a7813a04 | 2127 | } |
85aaf69f | 2128 | } |
85aaf69f SL |
2129 | } |
2130 | ||
a7813a04 XL |
2131 | /// Checks whether there is a local type somewhere in the chain of |
2132 | /// autoderefs of `rcvr_ty`. | |
cdc7bbd5 XL |
2133 | fn type_derefs_to_local( |
2134 | &self, | |
2135 | span: Span, | |
2136 | rcvr_ty: Ty<'tcx>, | |
2137 | source: SelfSource<'tcx>, | |
2138 | ) -> bool { | |
9fa01778 | 2139 | fn is_local(ty: Ty<'_>) -> bool { |
1b1a35ee | 2140 | match ty.kind() { |
5e7ed085 | 2141 | ty::Adt(def, _) => def.did().is_local(), |
b7449926 | 2142 | ty::Foreign(did) => did.is_local(), |
c295e0f8 | 2143 | ty::Dynamic(tr, ..) => tr.principal().map_or(false, |d| d.def_id().is_local()), |
b7449926 | 2144 | ty::Param(_) => true, |
a7813a04 | 2145 | |
0731742a XL |
2146 | // Everything else (primitive types, etc.) is effectively |
2147 | // non-local (there are "edge" cases, e.g., `(LocalType,)`, but | |
a7813a04 XL |
2148 | // the noise from these sort of types is usually just really |
2149 | // annoying, rather than any sort of help). | |
c30ab7b3 | 2150 | _ => false, |
a7813a04 | 2151 | } |
85aaf69f | 2152 | } |
85aaf69f | 2153 | |
a7813a04 XL |
2154 | // This occurs for UFCS desugaring of `T::method`, where there is no |
2155 | // receiver expression for the method call, and thus no autoderef. | |
0731742a | 2156 | if let SelfSource::QPath(_) = source { |
e74abb32 | 2157 | return is_local(self.resolve_vars_with_obligations(rcvr_ty)); |
c34b1796 | 2158 | } |
c34b1796 | 2159 | |
3157f602 | 2160 | self.autoderef(span, rcvr_ty).any(|(ty, _)| is_local(ty)) |
c34b1796 | 2161 | } |
85aaf69f SL |
2162 | } |
2163 | ||
cdc7bbd5 | 2164 | #[derive(Copy, Clone, Debug)] |
0731742a | 2165 | pub enum SelfSource<'a> { |
dfeec247 XL |
2166 | QPath(&'a hir::Ty<'a>), |
2167 | MethodCall(&'a hir::Expr<'a> /* rcvr */), | |
0731742a XL |
2168 | } |
2169 | ||
c34b1796 | 2170 | #[derive(Copy, Clone)] |
85aaf69f | 2171 | pub struct TraitInfo { |
e9174d1e | 2172 | pub def_id: DefId, |
85aaf69f SL |
2173 | } |
2174 | ||
85aaf69f SL |
2175 | impl PartialEq for TraitInfo { |
2176 | fn eq(&self, other: &TraitInfo) -> bool { | |
2177 | self.cmp(other) == Ordering::Equal | |
2178 | } | |
2179 | } | |
2180 | impl Eq for TraitInfo {} | |
2181 | impl PartialOrd for TraitInfo { | |
c30ab7b3 SL |
2182 | fn partial_cmp(&self, other: &TraitInfo) -> Option<Ordering> { |
2183 | Some(self.cmp(other)) | |
2184 | } | |
85aaf69f SL |
2185 | } |
2186 | impl Ord for TraitInfo { | |
2187 | fn cmp(&self, other: &TraitInfo) -> Ordering { | |
0731742a XL |
2188 | // Local crates are more important than remote ones (local: |
2189 | // `cnum == 0`), and otherwise we throw in the defid for totality. | |
85aaf69f | 2190 | |
b039eaaf SL |
2191 | let lhs = (other.def_id.krate, other.def_id); |
2192 | let rhs = (self.def_id.krate, self.def_id); | |
85aaf69f SL |
2193 | lhs.cmp(&rhs) |
2194 | } | |
2195 | } | |
2196 | ||
a2a8927a XL |
2197 | /// Retrieves all traits in this crate and any dependent crates, |
2198 | /// and wraps them into `TraitInfo` for custom sorting. | |
416331ca | 2199 | pub fn all_traits(tcx: TyCtxt<'_>) -> Vec<TraitInfo> { |
a2a8927a | 2200 | tcx.all_traits().map(|def_id| TraitInfo { def_id }).collect() |
85aaf69f | 2201 | } |
ff7c6d11 | 2202 | |
a2a8927a | 2203 | fn print_disambiguation_help<'tcx>( |
f9f354fc | 2204 | item_name: Ident, |
dfeec247 | 2205 | args: Option<&'tcx [hir::Expr<'tcx>]>, |
5e7ed085 | 2206 | err: &mut Diagnostic, |
dfeec247 XL |
2207 | trait_name: String, |
2208 | rcvr_ty: Ty<'_>, | |
2209 | kind: ty::AssocKind, | |
ba9703b0 | 2210 | def_id: DefId, |
dfeec247 XL |
2211 | span: Span, |
2212 | candidate: Option<usize>, | |
2213 | source_map: &source_map::SourceMap, | |
c295e0f8 | 2214 | fn_has_self_parameter: bool, |
dfeec247 XL |
2215 | ) { |
2216 | let mut applicability = Applicability::MachineApplicable; | |
94222f64 XL |
2217 | let (span, sugg) = if let (ty::AssocKind::Fn, Some(args)) = (kind, args) { |
2218 | let args = format!( | |
dfeec247 XL |
2219 | "({}{})", |
2220 | if rcvr_ty.is_region_ptr() { | |
2221 | if rcvr_ty.is_mutable_ptr() { "&mut " } else { "&" } | |
2222 | } else { | |
2223 | "" | |
2224 | }, | |
2225 | args.iter() | |
2226 | .map(|arg| source_map.span_to_snippet(arg.span).unwrap_or_else(|_| { | |
2227 | applicability = Applicability::HasPlaceholders; | |
2228 | "_".to_owned() | |
2229 | })) | |
2230 | .collect::<Vec<_>>() | |
2231 | .join(", "), | |
94222f64 | 2232 | ); |
c295e0f8 XL |
2233 | let trait_name = if !fn_has_self_parameter { |
2234 | format!("<{} as {}>", rcvr_ty, trait_name) | |
2235 | } else { | |
2236 | trait_name | |
2237 | }; | |
94222f64 | 2238 | (span, format!("{}::{}{}", trait_name, item_name, args)) |
dfeec247 | 2239 | } else { |
c295e0f8 | 2240 | (span.with_hi(item_name.span.lo()), format!("<{} as {}>::", rcvr_ty, trait_name)) |
dfeec247 | 2241 | }; |
94222f64 | 2242 | err.span_suggestion_verbose( |
dfeec247 XL |
2243 | span, |
2244 | &format!( | |
2245 | "disambiguate the {} for {}", | |
ba9703b0 | 2246 | kind.as_def_kind().descr(def_id), |
dfeec247 XL |
2247 | if let Some(candidate) = candidate { |
2248 | format!("candidate #{}", candidate) | |
2249 | } else { | |
2250 | "the candidate".to_string() | |
2251 | }, | |
2252 | ), | |
2253 | sugg, | |
2254 | applicability, | |
2255 | ); | |
2256 | } |