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Commit | Line | Data |
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29967ef6 XL |
1 | use crate::astconv::AstConv; |
2 | use crate::check::coercion::CoerceMany; | |
3 | use crate::check::method::MethodCallee; | |
4 | use crate::check::Expectation::*; | |
5 | use crate::check::TupleArgumentsFlag::*; | |
6 | use crate::check::{ | |
7 | potentially_plural_count, struct_span_err, BreakableCtxt, Diverges, Expectation, FnCtxt, | |
8 | LocalTy, Needs, TupleArgumentsFlag, | |
9 | }; | |
10 | ||
11 | use rustc_ast as ast; | |
c295e0f8 | 12 | use rustc_data_structures::sync::Lrc; |
29967ef6 XL |
13 | use rustc_errors::{Applicability, DiagnosticBuilder, DiagnosticId}; |
14 | use rustc_hir as hir; | |
136023e0 | 15 | use rustc_hir::def::{CtorOf, DefKind, Res}; |
29967ef6 XL |
16 | use rustc_hir::def_id::DefId; |
17 | use rustc_hir::{ExprKind, Node, QPath}; | |
18 | use rustc_middle::ty::adjustment::AllowTwoPhase; | |
19 | use rustc_middle::ty::fold::TypeFoldable; | |
20 | use rustc_middle::ty::{self, Ty}; | |
21 | use rustc_session::Session; | |
17df50a5 | 22 | use rustc_span::symbol::Ident; |
29967ef6 XL |
23 | use rustc_span::{self, MultiSpan, Span}; |
24 | use rustc_trait_selection::traits::{self, ObligationCauseCode, StatementAsExpression}; | |
25 | ||
5869c6ff | 26 | use crate::structured_errors::StructuredDiagnostic; |
cdc7bbd5 | 27 | use std::iter; |
29967ef6 XL |
28 | use std::slice; |
29 | ||
30 | impl<'a, 'tcx> FnCtxt<'a, 'tcx> { | |
31 | pub(in super::super) fn check_casts(&self) { | |
32 | let mut deferred_cast_checks = self.deferred_cast_checks.borrow_mut(); | |
94222f64 | 33 | debug!("FnCtxt::check_casts: {} deferred checks", deferred_cast_checks.len()); |
29967ef6 XL |
34 | for cast in deferred_cast_checks.drain(..) { |
35 | cast.check(self); | |
36 | } | |
37 | } | |
38 | ||
39 | pub(in super::super) fn check_method_argument_types( | |
40 | &self, | |
41 | sp: Span, | |
42 | expr: &'tcx hir::Expr<'tcx>, | |
43 | method: Result<MethodCallee<'tcx>, ()>, | |
44 | args_no_rcvr: &'tcx [hir::Expr<'tcx>], | |
45 | tuple_arguments: TupleArgumentsFlag, | |
46 | expected: Expectation<'tcx>, | |
47 | ) -> Ty<'tcx> { | |
48 | let has_error = match method { | |
49 | Ok(method) => method.substs.references_error() || method.sig.references_error(), | |
50 | Err(_) => true, | |
51 | }; | |
52 | if has_error { | |
53 | let err_inputs = self.err_args(args_no_rcvr.len()); | |
54 | ||
55 | let err_inputs = match tuple_arguments { | |
56 | DontTupleArguments => err_inputs, | |
57 | TupleArguments => vec![self.tcx.intern_tup(&err_inputs[..])], | |
58 | }; | |
59 | ||
60 | self.check_argument_types( | |
61 | sp, | |
62 | expr, | |
63 | &err_inputs[..], | |
64 | &[], | |
65 | args_no_rcvr, | |
66 | false, | |
67 | tuple_arguments, | |
68 | None, | |
69 | ); | |
70 | return self.tcx.ty_error(); | |
71 | } | |
72 | ||
73 | let method = method.unwrap(); | |
74 | // HACK(eddyb) ignore self in the definition (see above). | |
75 | let expected_arg_tys = self.expected_inputs_for_expected_output( | |
76 | sp, | |
77 | expected, | |
78 | method.sig.output(), | |
79 | &method.sig.inputs()[1..], | |
80 | ); | |
81 | self.check_argument_types( | |
82 | sp, | |
83 | expr, | |
84 | &method.sig.inputs()[1..], | |
85 | &expected_arg_tys[..], | |
86 | args_no_rcvr, | |
87 | method.sig.c_variadic, | |
88 | tuple_arguments, | |
89 | Some(method.def_id), | |
90 | ); | |
91 | method.sig.output() | |
92 | } | |
93 | ||
94 | /// Generic function that factors out common logic from function calls, | |
95 | /// method calls and overloaded operators. | |
96 | pub(in super::super) fn check_argument_types( | |
97 | &self, | |
98 | sp: Span, | |
99 | expr: &'tcx hir::Expr<'tcx>, | |
100 | fn_inputs: &[Ty<'tcx>], | |
101 | expected_arg_tys: &[Ty<'tcx>], | |
102 | args: &'tcx [hir::Expr<'tcx>], | |
103 | c_variadic: bool, | |
104 | tuple_arguments: TupleArgumentsFlag, | |
105 | def_id: Option<DefId>, | |
106 | ) { | |
107 | let tcx = self.tcx; | |
108 | // Grab the argument types, supplying fresh type variables | |
109 | // if the wrong number of arguments were supplied | |
110 | let supplied_arg_count = if tuple_arguments == DontTupleArguments { args.len() } else { 1 }; | |
111 | ||
112 | // All the input types from the fn signature must outlive the call | |
113 | // so as to validate implied bounds. | |
cdc7bbd5 | 114 | for (&fn_input_ty, arg_expr) in iter::zip(fn_inputs, args) { |
29967ef6 XL |
115 | self.register_wf_obligation(fn_input_ty.into(), arg_expr.span, traits::MiscObligation); |
116 | } | |
117 | ||
118 | let expected_arg_count = fn_inputs.len(); | |
119 | ||
120 | let param_count_error = |expected_count: usize, | |
121 | arg_count: usize, | |
122 | error_code: &str, | |
123 | c_variadic: bool, | |
124 | sugg_unit: bool| { | |
136023e0 XL |
125 | let (span, start_span, args, ctor_of) = match &expr.kind { |
126 | hir::ExprKind::Call( | |
127 | hir::Expr { | |
128 | span, | |
129 | kind: | |
130 | hir::ExprKind::Path(hir::QPath::Resolved( | |
131 | _, | |
132 | hir::Path { res: Res::Def(DefKind::Ctor(of, _), _), .. }, | |
133 | )), | |
134 | .. | |
135 | }, | |
136 | args, | |
137 | ) => (*span, *span, &args[..], Some(of)), | |
138 | hir::ExprKind::Call(hir::Expr { span, .. }, args) => { | |
139 | (*span, *span, &args[..], None) | |
140 | } | |
29967ef6 XL |
141 | hir::ExprKind::MethodCall(path_segment, span, args, _) => ( |
142 | *span, | |
143 | // `sp` doesn't point at the whole `foo.bar()`, only at `bar`. | |
144 | path_segment | |
145 | .args | |
146 | .and_then(|args| args.args.iter().last()) | |
147 | // Account for `foo.bar::<T>()`. | |
148 | .map(|arg| { | |
149 | // Skip the closing `>`. | |
150 | tcx.sess | |
151 | .source_map() | |
152 | .next_point(tcx.sess.source_map().next_point(arg.span())) | |
153 | }) | |
154 | .unwrap_or(*span), | |
155 | &args[1..], // Skip the receiver. | |
136023e0 | 156 | None, // methods are never ctors |
29967ef6 XL |
157 | ), |
158 | k => span_bug!(sp, "checking argument types on a non-call: `{:?}`", k), | |
159 | }; | |
160 | let arg_spans = if args.is_empty() { | |
161 | // foo() | |
162 | // ^^^-- supplied 0 arguments | |
163 | // | | |
164 | // expected 2 arguments | |
165 | vec![tcx.sess.source_map().next_point(start_span).with_hi(sp.hi())] | |
166 | } else { | |
167 | // foo(1, 2, 3) | |
168 | // ^^^ - - - supplied 3 arguments | |
169 | // | | |
170 | // expected 2 arguments | |
171 | args.iter().map(|arg| arg.span).collect::<Vec<Span>>() | |
172 | }; | |
173 | ||
174 | let mut err = tcx.sess.struct_span_err_with_code( | |
175 | span, | |
176 | &format!( | |
136023e0 XL |
177 | "this {} takes {}{} but {} {} supplied", |
178 | match ctor_of { | |
179 | Some(CtorOf::Struct) => "struct", | |
180 | Some(CtorOf::Variant) => "enum variant", | |
181 | None => "function", | |
182 | }, | |
29967ef6 XL |
183 | if c_variadic { "at least " } else { "" }, |
184 | potentially_plural_count(expected_count, "argument"), | |
185 | potentially_plural_count(arg_count, "argument"), | |
186 | if arg_count == 1 { "was" } else { "were" } | |
187 | ), | |
188 | DiagnosticId::Error(error_code.to_owned()), | |
189 | ); | |
190 | let label = format!("supplied {}", potentially_plural_count(arg_count, "argument")); | |
191 | for (i, span) in arg_spans.into_iter().enumerate() { | |
192 | err.span_label( | |
193 | span, | |
194 | if arg_count == 0 || i + 1 == arg_count { &label } else { "" }, | |
195 | ); | |
196 | } | |
197 | ||
198 | if let Some(def_id) = def_id { | |
5869c6ff XL |
199 | if let Some(def_span) = tcx.def_ident_span(def_id) { |
200 | let mut spans: MultiSpan = def_span.into(); | |
201 | ||
202 | let params = tcx | |
203 | .hir() | |
204 | .get_if_local(def_id) | |
205 | .and_then(|node| node.body_id()) | |
206 | .into_iter() | |
207 | .map(|id| tcx.hir().body(id).params) | |
208 | .flatten(); | |
209 | ||
210 | for param in params { | |
211 | spans.push_span_label(param.span, String::new()); | |
29967ef6 XL |
212 | } |
213 | ||
214 | let def_kind = tcx.def_kind(def_id); | |
215 | err.span_note(spans, &format!("{} defined here", def_kind.descr(def_id))); | |
216 | } | |
217 | } | |
218 | ||
219 | if sugg_unit { | |
220 | let sugg_span = tcx.sess.source_map().end_point(expr.span); | |
221 | // remove closing `)` from the span | |
222 | let sugg_span = sugg_span.shrink_to_lo(); | |
223 | err.span_suggestion( | |
224 | sugg_span, | |
225 | "expected the unit value `()`; create it with empty parentheses", | |
226 | String::from("()"), | |
227 | Applicability::MachineApplicable, | |
228 | ); | |
229 | } else { | |
230 | err.span_label( | |
231 | span, | |
232 | format!( | |
233 | "expected {}{}", | |
234 | if c_variadic { "at least " } else { "" }, | |
235 | potentially_plural_count(expected_count, "argument") | |
236 | ), | |
237 | ); | |
238 | } | |
239 | err.emit(); | |
240 | }; | |
241 | ||
242 | let mut expected_arg_tys = expected_arg_tys.to_vec(); | |
243 | ||
244 | let formal_tys = if tuple_arguments == TupleArguments { | |
245 | let tuple_type = self.structurally_resolved_type(sp, fn_inputs[0]); | |
246 | match tuple_type.kind() { | |
247 | ty::Tuple(arg_types) if arg_types.len() != args.len() => { | |
248 | param_count_error(arg_types.len(), args.len(), "E0057", false, false); | |
249 | expected_arg_tys = vec![]; | |
250 | self.err_args(args.len()) | |
251 | } | |
252 | ty::Tuple(arg_types) => { | |
253 | expected_arg_tys = match expected_arg_tys.get(0) { | |
254 | Some(&ty) => match ty.kind() { | |
255 | ty::Tuple(ref tys) => tys.iter().map(|k| k.expect_ty()).collect(), | |
256 | _ => vec![], | |
257 | }, | |
258 | None => vec![], | |
259 | }; | |
260 | arg_types.iter().map(|k| k.expect_ty()).collect() | |
261 | } | |
262 | _ => { | |
263 | struct_span_err!( | |
264 | tcx.sess, | |
265 | sp, | |
266 | E0059, | |
267 | "cannot use call notation; the first type parameter \ | |
268 | for the function trait is neither a tuple nor unit" | |
269 | ) | |
270 | .emit(); | |
271 | expected_arg_tys = vec![]; | |
272 | self.err_args(args.len()) | |
273 | } | |
274 | } | |
275 | } else if expected_arg_count == supplied_arg_count { | |
276 | fn_inputs.to_vec() | |
277 | } else if c_variadic { | |
278 | if supplied_arg_count >= expected_arg_count { | |
279 | fn_inputs.to_vec() | |
280 | } else { | |
281 | param_count_error(expected_arg_count, supplied_arg_count, "E0060", true, false); | |
282 | expected_arg_tys = vec![]; | |
283 | self.err_args(supplied_arg_count) | |
284 | } | |
285 | } else { | |
286 | // is the missing argument of type `()`? | |
287 | let sugg_unit = if expected_arg_tys.len() == 1 && supplied_arg_count == 0 { | |
fc512014 | 288 | self.resolve_vars_if_possible(expected_arg_tys[0]).is_unit() |
29967ef6 | 289 | } else if fn_inputs.len() == 1 && supplied_arg_count == 0 { |
fc512014 | 290 | self.resolve_vars_if_possible(fn_inputs[0]).is_unit() |
29967ef6 XL |
291 | } else { |
292 | false | |
293 | }; | |
294 | param_count_error(expected_arg_count, supplied_arg_count, "E0061", false, sugg_unit); | |
295 | ||
296 | expected_arg_tys = vec![]; | |
297 | self.err_args(supplied_arg_count) | |
298 | }; | |
299 | ||
300 | debug!( | |
301 | "check_argument_types: formal_tys={:?}", | |
302 | formal_tys.iter().map(|t| self.ty_to_string(*t)).collect::<Vec<String>>() | |
303 | ); | |
304 | ||
305 | // If there is no expectation, expect formal_tys. | |
306 | let expected_arg_tys = | |
307 | if !expected_arg_tys.is_empty() { expected_arg_tys } else { formal_tys.clone() }; | |
308 | ||
309 | let mut final_arg_types: Vec<(usize, Ty<'_>, Ty<'_>)> = vec![]; | |
310 | ||
311 | // Check the arguments. | |
312 | // We do this in a pretty awful way: first we type-check any arguments | |
313 | // that are not closures, then we type-check the closures. This is so | |
314 | // that we have more information about the types of arguments when we | |
315 | // type-check the functions. This isn't really the right way to do this. | |
136023e0 | 316 | for check_closures in [false, true] { |
29967ef6 XL |
317 | debug!("check_closures={}", check_closures); |
318 | ||
319 | // More awful hacks: before we check argument types, try to do | |
320 | // an "opportunistic" trait resolution of any trait bounds on | |
321 | // the call. This helps coercions. | |
322 | if check_closures { | |
323 | self.select_obligations_where_possible(false, |errors| { | |
324 | self.point_at_type_arg_instead_of_call_if_possible(errors, expr); | |
325 | self.point_at_arg_instead_of_call_if_possible( | |
326 | errors, | |
327 | &final_arg_types[..], | |
c295e0f8 | 328 | expr, |
29967ef6 XL |
329 | sp, |
330 | &args, | |
331 | ); | |
332 | }) | |
333 | } | |
334 | ||
335 | // For C-variadic functions, we don't have a declared type for all of | |
336 | // the arguments hence we only do our usual type checking with | |
337 | // the arguments who's types we do know. | |
338 | let t = if c_variadic { | |
339 | expected_arg_count | |
340 | } else if tuple_arguments == TupleArguments { | |
341 | args.len() | |
342 | } else { | |
343 | supplied_arg_count | |
344 | }; | |
345 | for (i, arg) in args.iter().take(t).enumerate() { | |
346 | // Warn only for the first loop (the "no closures" one). | |
347 | // Closure arguments themselves can't be diverging, but | |
348 | // a previous argument can, e.g., `foo(panic!(), || {})`. | |
349 | if !check_closures { | |
350 | self.warn_if_unreachable(arg.hir_id, arg.span, "expression"); | |
351 | } | |
352 | ||
5869c6ff | 353 | let is_closure = matches!(arg.kind, ExprKind::Closure(..)); |
29967ef6 XL |
354 | |
355 | if is_closure != check_closures { | |
356 | continue; | |
357 | } | |
358 | ||
29967ef6 | 359 | let formal_ty = formal_tys[i]; |
c295e0f8 | 360 | debug!("checking argument {}: {:?} = {:?}", i, arg, formal_ty); |
29967ef6 XL |
361 | |
362 | // The special-cased logic below has three functions: | |
363 | // 1. Provide as good of an expected type as possible. | |
364 | let expected = Expectation::rvalue_hint(self, expected_arg_tys[i]); | |
365 | ||
366 | let checked_ty = self.check_expr_with_expectation(&arg, expected); | |
367 | ||
368 | // 2. Coerce to the most detailed type that could be coerced | |
369 | // to, which is `expected_ty` if `rvalue_hint` returns an | |
370 | // `ExpectHasType(expected_ty)`, or the `formal_ty` otherwise. | |
371 | let coerce_ty = expected.only_has_type(self).unwrap_or(formal_ty); | |
c295e0f8 XL |
372 | |
373 | // Cause selection errors caused by resolving a single argument to point at the | |
374 | // argument and not the call. This is otherwise redundant with the `demand_coerce` | |
375 | // call immediately after, but it lets us customize the span pointed to in the | |
376 | // fulfillment error to be more accurate. | |
377 | let _ = self.resolve_vars_with_obligations_and_mutate_fulfillment( | |
378 | coerce_ty, | |
379 | |errors| { | |
380 | // This is not coming from a macro or a `derive`. | |
381 | if sp.desugaring_kind().is_none() | |
382 | && !arg.span.from_expansion() | |
383 | // Do not change the spans of `async fn`s. | |
384 | && !matches!( | |
385 | expr.kind, | |
386 | hir::ExprKind::Call( | |
387 | hir::Expr { | |
388 | kind: hir::ExprKind::Path(hir::QPath::LangItem(_, _)), | |
389 | .. | |
390 | }, | |
391 | _ | |
392 | ) | |
393 | ) { | |
394 | for error in errors { | |
395 | error.obligation.cause.make_mut().span = arg.span; | |
396 | let code = error.obligation.cause.code.clone(); | |
397 | error.obligation.cause.make_mut().code = | |
398 | ObligationCauseCode::FunctionArgumentObligation { | |
399 | arg_hir_id: arg.hir_id, | |
400 | call_hir_id: expr.hir_id, | |
401 | parent_code: Lrc::new(code), | |
402 | }; | |
403 | } | |
404 | } | |
405 | }, | |
406 | ); | |
407 | ||
29967ef6 XL |
408 | // We're processing function arguments so we definitely want to use |
409 | // two-phase borrows. | |
410 | self.demand_coerce(&arg, checked_ty, coerce_ty, None, AllowTwoPhase::Yes); | |
411 | final_arg_types.push((i, checked_ty, coerce_ty)); | |
412 | ||
413 | // 3. Relate the expected type and the formal one, | |
414 | // if the expected type was used for the coercion. | |
415 | self.demand_suptype(arg.span, formal_ty, coerce_ty); | |
416 | } | |
417 | } | |
418 | ||
419 | // We also need to make sure we at least write the ty of the other | |
420 | // arguments which we skipped above. | |
421 | if c_variadic { | |
5869c6ff XL |
422 | fn variadic_error<'tcx>(sess: &Session, span: Span, ty: Ty<'tcx>, cast_ty: &str) { |
423 | use crate::structured_errors::MissingCastForVariadicArg; | |
424 | ||
425 | MissingCastForVariadicArg { sess, span, ty, cast_ty }.diagnostic().emit() | |
29967ef6 XL |
426 | } |
427 | ||
428 | for arg in args.iter().skip(expected_arg_count) { | |
429 | let arg_ty = self.check_expr(&arg); | |
430 | ||
431 | // There are a few types which get autopromoted when passed via varargs | |
432 | // in C but we just error out instead and require explicit casts. | |
433 | let arg_ty = self.structurally_resolved_type(arg.span, arg_ty); | |
434 | match arg_ty.kind() { | |
5869c6ff | 435 | ty::Float(ty::FloatTy::F32) => { |
29967ef6 XL |
436 | variadic_error(tcx.sess, arg.span, arg_ty, "c_double"); |
437 | } | |
5869c6ff | 438 | ty::Int(ty::IntTy::I8 | ty::IntTy::I16) | ty::Bool => { |
29967ef6 XL |
439 | variadic_error(tcx.sess, arg.span, arg_ty, "c_int"); |
440 | } | |
5869c6ff | 441 | ty::Uint(ty::UintTy::U8 | ty::UintTy::U16) => { |
29967ef6 XL |
442 | variadic_error(tcx.sess, arg.span, arg_ty, "c_uint"); |
443 | } | |
444 | ty::FnDef(..) => { | |
445 | let ptr_ty = self.tcx.mk_fn_ptr(arg_ty.fn_sig(self.tcx)); | |
fc512014 | 446 | let ptr_ty = self.resolve_vars_if_possible(ptr_ty); |
29967ef6 XL |
447 | variadic_error(tcx.sess, arg.span, arg_ty, &ptr_ty.to_string()); |
448 | } | |
449 | _ => {} | |
450 | } | |
451 | } | |
452 | } | |
453 | } | |
454 | ||
455 | // AST fragment checking | |
456 | pub(in super::super) fn check_lit( | |
457 | &self, | |
458 | lit: &hir::Lit, | |
459 | expected: Expectation<'tcx>, | |
460 | ) -> Ty<'tcx> { | |
461 | let tcx = self.tcx; | |
462 | ||
463 | match lit.node { | |
464 | ast::LitKind::Str(..) => tcx.mk_static_str(), | |
465 | ast::LitKind::ByteStr(ref v) => { | |
466 | tcx.mk_imm_ref(tcx.lifetimes.re_static, tcx.mk_array(tcx.types.u8, v.len() as u64)) | |
467 | } | |
468 | ast::LitKind::Byte(_) => tcx.types.u8, | |
469 | ast::LitKind::Char(_) => tcx.types.char, | |
5869c6ff XL |
470 | ast::LitKind::Int(_, ast::LitIntType::Signed(t)) => tcx.mk_mach_int(ty::int_ty(t)), |
471 | ast::LitKind::Int(_, ast::LitIntType::Unsigned(t)) => tcx.mk_mach_uint(ty::uint_ty(t)), | |
29967ef6 XL |
472 | ast::LitKind::Int(_, ast::LitIntType::Unsuffixed) => { |
473 | let opt_ty = expected.to_option(self).and_then(|ty| match ty.kind() { | |
474 | ty::Int(_) | ty::Uint(_) => Some(ty), | |
475 | ty::Char => Some(tcx.types.u8), | |
476 | ty::RawPtr(..) => Some(tcx.types.usize), | |
477 | ty::FnDef(..) | ty::FnPtr(_) => Some(tcx.types.usize), | |
478 | _ => None, | |
479 | }); | |
480 | opt_ty.unwrap_or_else(|| self.next_int_var()) | |
481 | } | |
5869c6ff XL |
482 | ast::LitKind::Float(_, ast::LitFloatType::Suffixed(t)) => { |
483 | tcx.mk_mach_float(ty::float_ty(t)) | |
484 | } | |
29967ef6 XL |
485 | ast::LitKind::Float(_, ast::LitFloatType::Unsuffixed) => { |
486 | let opt_ty = expected.to_option(self).and_then(|ty| match ty.kind() { | |
487 | ty::Float(_) => Some(ty), | |
488 | _ => None, | |
489 | }); | |
490 | opt_ty.unwrap_or_else(|| self.next_float_var()) | |
491 | } | |
492 | ast::LitKind::Bool(_) => tcx.types.bool, | |
493 | ast::LitKind::Err(_) => tcx.ty_error(), | |
494 | } | |
495 | } | |
496 | ||
497 | pub fn check_struct_path( | |
498 | &self, | |
499 | qpath: &QPath<'_>, | |
500 | hir_id: hir::HirId, | |
501 | ) -> Option<(&'tcx ty::VariantDef, Ty<'tcx>)> { | |
6a06907d | 502 | let path_span = qpath.span(); |
29967ef6 XL |
503 | let (def, ty) = self.finish_resolving_struct_path(qpath, path_span, hir_id); |
504 | let variant = match def { | |
505 | Res::Err => { | |
506 | self.set_tainted_by_errors(); | |
507 | return None; | |
508 | } | |
509 | Res::Def(DefKind::Variant, _) => match ty.kind() { | |
510 | ty::Adt(adt, substs) => Some((adt.variant_of_res(def), adt.did, substs)), | |
511 | _ => bug!("unexpected type: {:?}", ty), | |
512 | }, | |
513 | Res::Def(DefKind::Struct | DefKind::Union | DefKind::TyAlias | DefKind::AssocTy, _) | |
514 | | Res::SelfTy(..) => match ty.kind() { | |
515 | ty::Adt(adt, substs) if !adt.is_enum() => { | |
516 | Some((adt.non_enum_variant(), adt.did, substs)) | |
517 | } | |
518 | _ => None, | |
519 | }, | |
520 | _ => bug!("unexpected definition: {:?}", def), | |
521 | }; | |
522 | ||
523 | if let Some((variant, did, substs)) = variant { | |
524 | debug!("check_struct_path: did={:?} substs={:?}", did, substs); | |
525 | self.write_user_type_annotation_from_substs(hir_id, did, substs, None); | |
526 | ||
527 | // Check bounds on type arguments used in the path. | |
528 | let (bounds, _) = self.instantiate_bounds(path_span, did, substs); | |
529 | let cause = | |
530 | traits::ObligationCause::new(path_span, self.body_id, traits::ItemObligation(did)); | |
531 | self.add_obligations_for_parameters(cause, bounds); | |
532 | ||
533 | Some((variant, ty)) | |
534 | } else { | |
c295e0f8 XL |
535 | match ty.kind() { |
536 | ty::Error(_) => { | |
537 | // E0071 might be caused by a spelling error, which will have | |
538 | // already caused an error message and probably a suggestion | |
539 | // elsewhere. Refrain from emitting more unhelpful errors here | |
540 | // (issue #88844). | |
541 | } | |
542 | _ => { | |
543 | struct_span_err!( | |
544 | self.tcx.sess, | |
545 | path_span, | |
546 | E0071, | |
547 | "expected struct, variant or union type, found {}", | |
548 | ty.sort_string(self.tcx) | |
549 | ) | |
550 | .span_label(path_span, "not a struct") | |
551 | .emit(); | |
552 | } | |
553 | } | |
29967ef6 XL |
554 | None |
555 | } | |
556 | } | |
557 | ||
558 | pub fn check_decl_initializer( | |
559 | &self, | |
560 | local: &'tcx hir::Local<'tcx>, | |
561 | init: &'tcx hir::Expr<'tcx>, | |
562 | ) -> Ty<'tcx> { | |
563 | // FIXME(tschottdorf): `contains_explicit_ref_binding()` must be removed | |
564 | // for #42640 (default match binding modes). | |
565 | // | |
566 | // See #44848. | |
567 | let ref_bindings = local.pat.contains_explicit_ref_binding(); | |
568 | ||
569 | let local_ty = self.local_ty(init.span, local.hir_id).revealed_ty; | |
570 | if let Some(m) = ref_bindings { | |
571 | // Somewhat subtle: if we have a `ref` binding in the pattern, | |
572 | // we want to avoid introducing coercions for the RHS. This is | |
573 | // both because it helps preserve sanity and, in the case of | |
574 | // ref mut, for soundness (issue #23116). In particular, in | |
575 | // the latter case, we need to be clear that the type of the | |
576 | // referent for the reference that results is *equal to* the | |
577 | // type of the place it is referencing, and not some | |
578 | // supertype thereof. | |
579 | let init_ty = self.check_expr_with_needs(init, Needs::maybe_mut_place(m)); | |
580 | self.demand_eqtype(init.span, local_ty, init_ty); | |
581 | init_ty | |
582 | } else { | |
583 | self.check_expr_coercable_to_type(init, local_ty, None) | |
584 | } | |
585 | } | |
586 | ||
587 | /// Type check a `let` statement. | |
588 | pub fn check_decl_local(&self, local: &'tcx hir::Local<'tcx>) { | |
589 | // Determine and write the type which we'll check the pattern against. | |
590 | let ty = self.local_ty(local.span, local.hir_id).decl_ty; | |
591 | self.write_ty(local.hir_id, ty); | |
592 | ||
593 | // Type check the initializer. | |
594 | if let Some(ref init) = local.init { | |
595 | let init_ty = self.check_decl_initializer(local, &init); | |
596 | self.overwrite_local_ty_if_err(local, ty, init_ty); | |
597 | } | |
598 | ||
599 | // Does the expected pattern type originate from an expression and what is the span? | |
600 | let (origin_expr, ty_span) = match (local.ty, local.init) { | |
601 | (Some(ty), _) => (false, Some(ty.span)), // Bias towards the explicit user type. | |
602 | (_, Some(init)) => (true, Some(init.span)), // No explicit type; so use the scrutinee. | |
603 | _ => (false, None), // We have `let $pat;`, so the expected type is unconstrained. | |
604 | }; | |
605 | ||
606 | // Type check the pattern. Override if necessary to avoid knock-on errors. | |
607 | self.check_pat_top(&local.pat, ty, ty_span, origin_expr); | |
608 | let pat_ty = self.node_ty(local.pat.hir_id); | |
609 | self.overwrite_local_ty_if_err(local, ty, pat_ty); | |
610 | } | |
611 | ||
6a06907d | 612 | pub fn check_stmt(&self, stmt: &'tcx hir::Stmt<'tcx>, is_last: bool) { |
29967ef6 XL |
613 | // Don't do all the complex logic below for `DeclItem`. |
614 | match stmt.kind { | |
615 | hir::StmtKind::Item(..) => return, | |
616 | hir::StmtKind::Local(..) | hir::StmtKind::Expr(..) | hir::StmtKind::Semi(..) => {} | |
617 | } | |
618 | ||
619 | self.warn_if_unreachable(stmt.hir_id, stmt.span, "statement"); | |
620 | ||
621 | // Hide the outer diverging and `has_errors` flags. | |
622 | let old_diverges = self.diverges.replace(Diverges::Maybe); | |
623 | let old_has_errors = self.has_errors.replace(false); | |
624 | ||
625 | match stmt.kind { | |
626 | hir::StmtKind::Local(ref l) => { | |
627 | self.check_decl_local(&l); | |
628 | } | |
629 | // Ignore for now. | |
630 | hir::StmtKind::Item(_) => {} | |
631 | hir::StmtKind::Expr(ref expr) => { | |
632 | // Check with expected type of `()`. | |
633 | self.check_expr_has_type_or_error(&expr, self.tcx.mk_unit(), |err| { | |
6a06907d XL |
634 | if expr.can_have_side_effects() { |
635 | self.suggest_semicolon_at_end(expr.span, err); | |
636 | } | |
29967ef6 XL |
637 | }); |
638 | } | |
639 | hir::StmtKind::Semi(ref expr) => { | |
6a06907d XL |
640 | // All of this is equivalent to calling `check_expr`, but it is inlined out here |
641 | // in order to capture the fact that this `match` is the last statement in its | |
642 | // function. This is done for better suggestions to remove the `;`. | |
643 | let expectation = match expr.kind { | |
644 | hir::ExprKind::Match(..) if is_last => IsLast(stmt.span), | |
645 | _ => NoExpectation, | |
646 | }; | |
647 | self.check_expr_with_expectation(expr, expectation); | |
29967ef6 XL |
648 | } |
649 | } | |
650 | ||
651 | // Combine the diverging and `has_error` flags. | |
652 | self.diverges.set(self.diverges.get() | old_diverges); | |
653 | self.has_errors.set(self.has_errors.get() | old_has_errors); | |
654 | } | |
655 | ||
656 | pub fn check_block_no_value(&self, blk: &'tcx hir::Block<'tcx>) { | |
657 | let unit = self.tcx.mk_unit(); | |
658 | let ty = self.check_block_with_expected(blk, ExpectHasType(unit)); | |
659 | ||
660 | // if the block produces a `!` value, that can always be | |
661 | // (effectively) coerced to unit. | |
662 | if !ty.is_never() { | |
663 | self.demand_suptype(blk.span, unit, ty); | |
664 | } | |
665 | } | |
666 | ||
667 | pub(in super::super) fn check_block_with_expected( | |
668 | &self, | |
669 | blk: &'tcx hir::Block<'tcx>, | |
670 | expected: Expectation<'tcx>, | |
671 | ) -> Ty<'tcx> { | |
5869c6ff | 672 | let prev = self.ps.replace(self.ps.get().recurse(blk)); |
29967ef6 XL |
673 | |
674 | // In some cases, blocks have just one exit, but other blocks | |
675 | // can be targeted by multiple breaks. This can happen both | |
676 | // with labeled blocks as well as when we desugar | |
677 | // a `try { ... }` expression. | |
678 | // | |
679 | // Example 1: | |
680 | // | |
681 | // 'a: { if true { break 'a Err(()); } Ok(()) } | |
682 | // | |
683 | // Here we would wind up with two coercions, one from | |
684 | // `Err(())` and the other from the tail expression | |
685 | // `Ok(())`. If the tail expression is omitted, that's a | |
686 | // "forced unit" -- unless the block diverges, in which | |
687 | // case we can ignore the tail expression (e.g., `'a: { | |
688 | // break 'a 22; }` would not force the type of the block | |
689 | // to be `()`). | |
690 | let tail_expr = blk.expr.as_ref(); | |
691 | let coerce_to_ty = expected.coercion_target_type(self, blk.span); | |
692 | let coerce = if blk.targeted_by_break { | |
693 | CoerceMany::new(coerce_to_ty) | |
694 | } else { | |
695 | let tail_expr: &[&hir::Expr<'_>] = match tail_expr { | |
696 | Some(e) => slice::from_ref(e), | |
697 | None => &[], | |
698 | }; | |
699 | CoerceMany::with_coercion_sites(coerce_to_ty, tail_expr) | |
700 | }; | |
701 | ||
702 | let prev_diverges = self.diverges.get(); | |
703 | let ctxt = BreakableCtxt { coerce: Some(coerce), may_break: false }; | |
704 | ||
705 | let (ctxt, ()) = self.with_breakable_ctxt(blk.hir_id, ctxt, || { | |
6a06907d XL |
706 | for (pos, s) in blk.stmts.iter().enumerate() { |
707 | self.check_stmt(s, blk.stmts.len() - 1 == pos); | |
29967ef6 XL |
708 | } |
709 | ||
710 | // check the tail expression **without** holding the | |
711 | // `enclosing_breakables` lock below. | |
712 | let tail_expr_ty = tail_expr.map(|t| self.check_expr_with_expectation(t, expected)); | |
713 | ||
714 | let mut enclosing_breakables = self.enclosing_breakables.borrow_mut(); | |
715 | let ctxt = enclosing_breakables.find_breakable(blk.hir_id); | |
716 | let coerce = ctxt.coerce.as_mut().unwrap(); | |
717 | if let Some(tail_expr_ty) = tail_expr_ty { | |
718 | let tail_expr = tail_expr.unwrap(); | |
719 | let span = self.get_expr_coercion_span(tail_expr); | |
720 | let cause = self.cause(span, ObligationCauseCode::BlockTailExpression(blk.hir_id)); | |
721 | coerce.coerce(self, &cause, tail_expr, tail_expr_ty); | |
722 | } else { | |
723 | // Subtle: if there is no explicit tail expression, | |
724 | // that is typically equivalent to a tail expression | |
725 | // of `()` -- except if the block diverges. In that | |
726 | // case, there is no value supplied from the tail | |
727 | // expression (assuming there are no other breaks, | |
728 | // this implies that the type of the block will be | |
729 | // `!`). | |
730 | // | |
731 | // #41425 -- label the implicit `()` as being the | |
732 | // "found type" here, rather than the "expected type". | |
733 | if !self.diverges.get().is_always() { | |
734 | // #50009 -- Do not point at the entire fn block span, point at the return type | |
735 | // span, as it is the cause of the requirement, and | |
736 | // `consider_hint_about_removing_semicolon` will point at the last expression | |
737 | // if it were a relevant part of the error. This improves usability in editors | |
738 | // that highlight errors inline. | |
739 | let mut sp = blk.span; | |
740 | let mut fn_span = None; | |
741 | if let Some((decl, ident)) = self.get_parent_fn_decl(blk.hir_id) { | |
742 | let ret_sp = decl.output.span(); | |
743 | if let Some(block_sp) = self.parent_item_span(blk.hir_id) { | |
744 | // HACK: on some cases (`ui/liveness/liveness-issue-2163.rs`) the | |
745 | // output would otherwise be incorrect and even misleading. Make sure | |
746 | // the span we're aiming at correspond to a `fn` body. | |
747 | if block_sp == blk.span { | |
748 | sp = ret_sp; | |
749 | fn_span = Some(ident.span); | |
750 | } | |
751 | } | |
752 | } | |
753 | coerce.coerce_forced_unit( | |
754 | self, | |
755 | &self.misc(sp), | |
756 | &mut |err| { | |
757 | if let Some(expected_ty) = expected.only_has_type(self) { | |
758 | self.consider_hint_about_removing_semicolon(blk, expected_ty, err); | |
759 | } | |
760 | if let Some(fn_span) = fn_span { | |
761 | err.span_label( | |
762 | fn_span, | |
763 | "implicitly returns `()` as its body has no tail or `return` \ | |
764 | expression", | |
765 | ); | |
766 | } | |
767 | }, | |
768 | false, | |
769 | ); | |
770 | } | |
771 | } | |
772 | }); | |
773 | ||
774 | if ctxt.may_break { | |
775 | // If we can break from the block, then the block's exit is always reachable | |
776 | // (... as long as the entry is reachable) - regardless of the tail of the block. | |
777 | self.diverges.set(prev_diverges); | |
778 | } | |
779 | ||
780 | let mut ty = ctxt.coerce.unwrap().complete(self); | |
781 | ||
782 | if self.has_errors.get() || ty.references_error() { | |
783 | ty = self.tcx.ty_error() | |
784 | } | |
785 | ||
786 | self.write_ty(blk.hir_id, ty); | |
787 | ||
5869c6ff | 788 | self.ps.set(prev); |
29967ef6 XL |
789 | ty |
790 | } | |
791 | ||
29967ef6 XL |
792 | /// A common error is to add an extra semicolon: |
793 | /// | |
794 | /// ``` | |
795 | /// fn foo() -> usize { | |
796 | /// 22; | |
797 | /// } | |
798 | /// ``` | |
799 | /// | |
800 | /// This routine checks if the final statement in a block is an | |
801 | /// expression with an explicit semicolon whose type is compatible | |
802 | /// with `expected_ty`. If so, it suggests removing the semicolon. | |
803 | fn consider_hint_about_removing_semicolon( | |
804 | &self, | |
805 | blk: &'tcx hir::Block<'tcx>, | |
806 | expected_ty: Ty<'tcx>, | |
807 | err: &mut DiagnosticBuilder<'_>, | |
808 | ) { | |
809 | if let Some((span_semi, boxed)) = self.could_remove_semicolon(blk, expected_ty) { | |
810 | if let StatementAsExpression::NeedsBoxing = boxed { | |
811 | err.span_suggestion_verbose( | |
812 | span_semi, | |
813 | "consider removing this semicolon and boxing the expression", | |
814 | String::new(), | |
815 | Applicability::HasPlaceholders, | |
816 | ); | |
817 | } else { | |
818 | err.span_suggestion_short( | |
819 | span_semi, | |
820 | "consider removing this semicolon", | |
821 | String::new(), | |
822 | Applicability::MachineApplicable, | |
823 | ); | |
824 | } | |
825 | } | |
826 | } | |
827 | ||
828 | fn parent_item_span(&self, id: hir::HirId) -> Option<Span> { | |
829 | let node = self.tcx.hir().get(self.tcx.hir().get_parent_item(id)); | |
830 | match node { | |
831 | Node::Item(&hir::Item { kind: hir::ItemKind::Fn(_, _, body_id), .. }) | |
832 | | Node::ImplItem(&hir::ImplItem { kind: hir::ImplItemKind::Fn(_, body_id), .. }) => { | |
833 | let body = self.tcx.hir().body(body_id); | |
834 | if let ExprKind::Block(block, _) = &body.value.kind { | |
835 | return Some(block.span); | |
836 | } | |
837 | } | |
838 | _ => {} | |
839 | } | |
840 | None | |
841 | } | |
842 | ||
843 | /// Given a function block's `HirId`, returns its `FnDecl` if it exists, or `None` otherwise. | |
844 | fn get_parent_fn_decl(&self, blk_id: hir::HirId) -> Option<(&'tcx hir::FnDecl<'tcx>, Ident)> { | |
845 | let parent = self.tcx.hir().get(self.tcx.hir().get_parent_item(blk_id)); | |
846 | self.get_node_fn_decl(parent).map(|(fn_decl, ident, _)| (fn_decl, ident)) | |
847 | } | |
848 | ||
849 | /// If `expr` is a `match` expression that has only one non-`!` arm, use that arm's tail | |
850 | /// expression's `Span`, otherwise return `expr.span`. This is done to give better errors | |
851 | /// when given code like the following: | |
852 | /// ```text | |
853 | /// if false { return 0i32; } else { 1u32 } | |
854 | /// // ^^^^ point at this instead of the whole `if` expression | |
855 | /// ``` | |
856 | fn get_expr_coercion_span(&self, expr: &hir::Expr<'_>) -> rustc_span::Span { | |
5869c6ff XL |
857 | let check_in_progress = |elem: &hir::Expr<'_>| { |
858 | self.in_progress_typeck_results | |
859 | .and_then(|typeck_results| typeck_results.borrow().node_type_opt(elem.hir_id)) | |
860 | .and_then(|ty| { | |
861 | if ty.is_never() { | |
862 | None | |
863 | } else { | |
864 | Some(match elem.kind { | |
865 | // Point at the tail expression when possible. | |
866 | hir::ExprKind::Block(block, _) => { | |
867 | block.expr.map_or(block.span, |e| e.span) | |
29967ef6 | 868 | } |
5869c6ff | 869 | _ => elem.span, |
29967ef6 | 870 | }) |
5869c6ff | 871 | } |
29967ef6 | 872 | }) |
5869c6ff XL |
873 | }; |
874 | ||
875 | if let hir::ExprKind::If(_, _, Some(el)) = expr.kind { | |
876 | if let Some(rslt) = check_in_progress(el) { | |
877 | return rslt; | |
29967ef6 XL |
878 | } |
879 | } | |
5869c6ff XL |
880 | |
881 | if let hir::ExprKind::Match(_, arms, _) = expr.kind { | |
882 | let mut iter = arms.iter().filter_map(|arm| check_in_progress(arm.body)); | |
883 | if let Some(span) = iter.next() { | |
884 | if iter.next().is_none() { | |
885 | return span; | |
886 | } | |
887 | } | |
888 | } | |
889 | ||
29967ef6 XL |
890 | expr.span |
891 | } | |
892 | ||
893 | fn overwrite_local_ty_if_err( | |
894 | &self, | |
895 | local: &'tcx hir::Local<'tcx>, | |
896 | decl_ty: Ty<'tcx>, | |
897 | ty: Ty<'tcx>, | |
898 | ) { | |
899 | if ty.references_error() { | |
900 | // Override the types everywhere with `err()` to avoid knock on errors. | |
901 | self.write_ty(local.hir_id, ty); | |
902 | self.write_ty(local.pat.hir_id, ty); | |
903 | let local_ty = LocalTy { decl_ty, revealed_ty: ty }; | |
904 | self.locals.borrow_mut().insert(local.hir_id, local_ty); | |
905 | self.locals.borrow_mut().insert(local.pat.hir_id, local_ty); | |
906 | } | |
907 | } | |
908 | ||
909 | // Finish resolving a path in a struct expression or pattern `S::A { .. }` if necessary. | |
910 | // The newly resolved definition is written into `type_dependent_defs`. | |
911 | fn finish_resolving_struct_path( | |
912 | &self, | |
913 | qpath: &QPath<'_>, | |
914 | path_span: Span, | |
915 | hir_id: hir::HirId, | |
916 | ) -> (Res, Ty<'tcx>) { | |
917 | match *qpath { | |
918 | QPath::Resolved(ref maybe_qself, ref path) => { | |
919 | let self_ty = maybe_qself.as_ref().map(|qself| self.to_ty(qself)); | |
6a06907d | 920 | let ty = <dyn AstConv<'_>>::res_to_ty(self, self_ty, path, true); |
29967ef6 XL |
921 | (path.res, ty) |
922 | } | |
923 | QPath::TypeRelative(ref qself, ref segment) => { | |
924 | let ty = self.to_ty(qself); | |
925 | ||
926 | let res = if let hir::TyKind::Path(QPath::Resolved(_, ref path)) = qself.kind { | |
927 | path.res | |
928 | } else { | |
929 | Res::Err | |
930 | }; | |
6a06907d XL |
931 | let result = <dyn AstConv<'_>>::associated_path_to_ty( |
932 | self, hir_id, path_span, ty, res, segment, true, | |
933 | ); | |
29967ef6 XL |
934 | let ty = result.map(|(ty, _, _)| ty).unwrap_or_else(|_| self.tcx().ty_error()); |
935 | let result = result.map(|(_, kind, def_id)| (kind, def_id)); | |
936 | ||
937 | // Write back the new resolution. | |
938 | self.write_resolution(hir_id, result); | |
939 | ||
5869c6ff | 940 | (result.map_or(Res::Err, |(kind, def_id)| Res::Def(kind, def_id)), ty) |
29967ef6 XL |
941 | } |
942 | QPath::LangItem(lang_item, span) => { | |
943 | self.resolve_lang_item_path(lang_item, span, hir_id) | |
944 | } | |
945 | } | |
946 | } | |
947 | ||
948 | /// Given a vec of evaluated `FulfillmentError`s and an `fn` call argument expressions, we walk | |
949 | /// the checked and coerced types for each argument to see if any of the `FulfillmentError`s | |
950 | /// reference a type argument. The reason to walk also the checked type is that the coerced type | |
951 | /// can be not easily comparable with predicate type (because of coercion). If the types match | |
952 | /// for either checked or coerced type, and there's only *one* argument that does, we point at | |
953 | /// the corresponding argument's expression span instead of the `fn` call path span. | |
954 | fn point_at_arg_instead_of_call_if_possible( | |
955 | &self, | |
956 | errors: &mut Vec<traits::FulfillmentError<'tcx>>, | |
957 | final_arg_types: &[(usize, Ty<'tcx>, Ty<'tcx>)], | |
c295e0f8 | 958 | expr: &'tcx hir::Expr<'tcx>, |
29967ef6 XL |
959 | call_sp: Span, |
960 | args: &'tcx [hir::Expr<'tcx>], | |
961 | ) { | |
962 | // We *do not* do this for desugared call spans to keep good diagnostics when involving | |
963 | // the `?` operator. | |
964 | if call_sp.desugaring_kind().is_some() { | |
965 | return; | |
966 | } | |
967 | ||
968 | for error in errors { | |
969 | // Only if the cause is somewhere inside the expression we want try to point at arg. | |
970 | // Otherwise, it means that the cause is somewhere else and we should not change | |
971 | // anything because we can break the correct span. | |
972 | if !call_sp.contains(error.obligation.cause.span) { | |
973 | continue; | |
974 | } | |
975 | ||
94222f64 | 976 | if let ty::PredicateKind::Trait(predicate) = |
5869c6ff | 977 | error.obligation.predicate.kind().skip_binder() |
29967ef6 XL |
978 | { |
979 | // Collect the argument position for all arguments that could have caused this | |
980 | // `FulfillmentError`. | |
981 | let mut referenced_in = final_arg_types | |
982 | .iter() | |
983 | .map(|&(i, checked_ty, _)| (i, checked_ty)) | |
984 | .chain(final_arg_types.iter().map(|&(i, _, coerced_ty)| (i, coerced_ty))) | |
985 | .flat_map(|(i, ty)| { | |
fc512014 | 986 | let ty = self.resolve_vars_if_possible(ty); |
29967ef6 XL |
987 | // We walk the argument type because the argument's type could have |
988 | // been `Option<T>`, but the `FulfillmentError` references `T`. | |
94222f64 | 989 | if ty.walk(self.tcx).any(|arg| arg == predicate.self_ty().into()) { |
29967ef6 XL |
990 | Some(i) |
991 | } else { | |
992 | None | |
993 | } | |
994 | }) | |
995 | .collect::<Vec<usize>>(); | |
996 | ||
997 | // Both checked and coerced types could have matched, thus we need to remove | |
998 | // duplicates. | |
999 | ||
1000 | // We sort primitive type usize here and can use unstable sort | |
1001 | referenced_in.sort_unstable(); | |
1002 | referenced_in.dedup(); | |
1003 | ||
1004 | if let (Some(ref_in), None) = (referenced_in.pop(), referenced_in.pop()) { | |
1005 | // We make sure that only *one* argument matches the obligation failure | |
1006 | // and we assign the obligation's span to its expression's. | |
1007 | error.obligation.cause.make_mut().span = args[ref_in].span; | |
c295e0f8 XL |
1008 | let code = error.obligation.cause.code.clone(); |
1009 | error.obligation.cause.make_mut().code = | |
1010 | ObligationCauseCode::FunctionArgumentObligation { | |
1011 | arg_hir_id: args[ref_in].hir_id, | |
1012 | call_hir_id: expr.hir_id, | |
1013 | parent_code: Lrc::new(code), | |
1014 | }; | |
29967ef6 XL |
1015 | } |
1016 | } | |
1017 | } | |
1018 | } | |
1019 | ||
1020 | /// Given a vec of evaluated `FulfillmentError`s and an `fn` call expression, we walk the | |
1021 | /// `PathSegment`s and resolve their type parameters to see if any of the `FulfillmentError`s | |
1022 | /// were caused by them. If they were, we point at the corresponding type argument's span | |
1023 | /// instead of the `fn` call path span. | |
1024 | fn point_at_type_arg_instead_of_call_if_possible( | |
1025 | &self, | |
1026 | errors: &mut Vec<traits::FulfillmentError<'tcx>>, | |
1027 | call_expr: &'tcx hir::Expr<'tcx>, | |
1028 | ) { | |
1029 | if let hir::ExprKind::Call(path, _) = &call_expr.kind { | |
1030 | if let hir::ExprKind::Path(qpath) = &path.kind { | |
1031 | if let hir::QPath::Resolved(_, path) = &qpath { | |
1032 | for error in errors { | |
94222f64 | 1033 | if let ty::PredicateKind::Trait(predicate) = |
5869c6ff | 1034 | error.obligation.predicate.kind().skip_binder() |
29967ef6 XL |
1035 | { |
1036 | // If any of the type arguments in this path segment caused the | |
17df50a5 | 1037 | // `FulfillmentError`, point at its span (#61860). |
29967ef6 XL |
1038 | for arg in path |
1039 | .segments | |
1040 | .iter() | |
1041 | .filter_map(|seg| seg.args.as_ref()) | |
1042 | .flat_map(|a| a.args.iter()) | |
1043 | { | |
1044 | if let hir::GenericArg::Type(hir_ty) = &arg { | |
1045 | if let hir::TyKind::Path(hir::QPath::TypeRelative(..)) = | |
1046 | &hir_ty.kind | |
1047 | { | |
1048 | // Avoid ICE with associated types. As this is best | |
1049 | // effort only, it's ok to ignore the case. It | |
1050 | // would trigger in `is_send::<T::AssocType>();` | |
1051 | // from `typeck-default-trait-impl-assoc-type.rs`. | |
1052 | } else { | |
6a06907d | 1053 | let ty = <dyn AstConv<'_>>::ast_ty_to_ty(self, hir_ty); |
fc512014 | 1054 | let ty = self.resolve_vars_if_possible(ty); |
29967ef6 XL |
1055 | if ty == predicate.self_ty() { |
1056 | error.obligation.cause.make_mut().span = hir_ty.span; | |
1057 | } | |
1058 | } | |
1059 | } | |
1060 | } | |
1061 | } | |
1062 | } | |
1063 | } | |
1064 | } | |
1065 | } | |
1066 | } | |
1067 | } |