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Commit | Line | Data |
---|---|---|
9fa01778 | 1 | use crate::check::FnCtxt; |
74b04a01 | 2 | use rustc_infer::infer::InferOk; |
ba9703b0 | 3 | use rustc_trait_selection::infer::InferCtxtExt as _; |
f9f354fc | 4 | use rustc_trait_selection::traits::ObligationCause; |
1a4d82fc | 5 | |
74b04a01 | 6 | use rustc_ast::util::parser::PREC_POSTFIX; |
dfeec247 XL |
7 | use rustc_errors::{Applicability, DiagnosticBuilder}; |
8 | use rustc_hir as hir; | |
f9f354fc | 9 | use rustc_hir::lang_items::CloneTraitLangItem; |
ba9703b0 XL |
10 | use rustc_hir::{is_range_literal, Node}; |
11 | use rustc_middle::ty::adjustment::AllowTwoPhase; | |
f9f354fc | 12 | use rustc_middle::ty::{self, AssocItem, Ty, TypeAndMut}; |
dfeec247 XL |
13 | use rustc_span::symbol::sym; |
14 | use rustc_span::Span; | |
32a655c1 SL |
15 | |
16 | use super::method::probe; | |
1a4d82fc | 17 | |
f035d41b XL |
18 | use std::fmt; |
19 | ||
dc9dc135 | 20 | impl<'a, 'tcx> FnCtxt<'a, 'tcx> { |
60c5eb7d XL |
21 | pub fn emit_coerce_suggestions( |
22 | &self, | |
23 | err: &mut DiagnosticBuilder<'_>, | |
dfeec247 | 24 | expr: &hir::Expr<'_>, |
60c5eb7d | 25 | expr_ty: Ty<'tcx>, |
dfeec247 | 26 | expected: Ty<'tcx>, |
f035d41b | 27 | expected_ty_expr: Option<&'tcx hir::Expr<'tcx>>, |
60c5eb7d XL |
28 | ) { |
29 | self.annotate_expected_due_to_let_ty(err, expr); | |
30 | self.suggest_compatible_variants(err, expr, expected, expr_ty); | |
f035d41b | 31 | self.suggest_deref_ref_or_into(err, expr, expected, expr_ty, expected_ty_expr); |
74b04a01 XL |
32 | if self.suggest_calling_boxed_future_when_appropriate(err, expr, expected, expr_ty) { |
33 | return; | |
34 | } | |
60c5eb7d XL |
35 | self.suggest_boxing_when_appropriate(err, expr, expected, expr_ty); |
36 | self.suggest_missing_await(err, expr, expected, expr_ty); | |
f035d41b | 37 | self.note_need_for_fn_pointer(err, expected, expr_ty); |
60c5eb7d XL |
38 | } |
39 | ||
a7813a04 XL |
40 | // Requires that the two types unify, and prints an error message if |
41 | // they don't. | |
42 | pub fn demand_suptype(&self, sp: Span, expected: Ty<'tcx>, actual: Ty<'tcx>) { | |
f9f354fc XL |
43 | if let Some(mut e) = self.demand_suptype_diag(sp, expected, actual) { |
44 | e.emit(); | |
45 | } | |
041b39d2 XL |
46 | } |
47 | ||
dfeec247 XL |
48 | pub fn demand_suptype_diag( |
49 | &self, | |
50 | sp: Span, | |
51 | expected: Ty<'tcx>, | |
52 | actual: Ty<'tcx>, | |
53 | ) -> Option<DiagnosticBuilder<'tcx>> { | |
74b04a01 XL |
54 | self.demand_suptype_with_origin(&self.misc(sp), expected, actual) |
55 | } | |
56 | ||
57 | pub fn demand_suptype_with_origin( | |
58 | &self, | |
59 | cause: &ObligationCause<'tcx>, | |
60 | expected: Ty<'tcx>, | |
61 | actual: Ty<'tcx>, | |
62 | ) -> Option<DiagnosticBuilder<'tcx>> { | |
7cac9316 | 63 | match self.at(cause, self.param_env).sup(expected, actual) { |
476ff2be SL |
64 | Ok(InferOk { obligations, value: () }) => { |
65 | self.register_predicates(obligations); | |
041b39d2 | 66 | None |
a7813a04 | 67 | } |
dfeec247 | 68 | Err(e) => Some(self.report_mismatched_types(&cause, expected, actual, e)), |
54a0048b | 69 | } |
1a4d82fc | 70 | } |
1a4d82fc | 71 | |
a7813a04 | 72 | pub fn demand_eqtype(&self, sp: Span, expected: Ty<'tcx>, actual: Ty<'tcx>) { |
32a655c1 SL |
73 | if let Some(mut err) = self.demand_eqtype_diag(sp, expected, actual) { |
74 | err.emit(); | |
75 | } | |
76 | } | |
77 | ||
dfeec247 XL |
78 | pub fn demand_eqtype_diag( |
79 | &self, | |
80 | sp: Span, | |
81 | expected: Ty<'tcx>, | |
82 | actual: Ty<'tcx>, | |
83 | ) -> Option<DiagnosticBuilder<'tcx>> { | |
32a655c1 | 84 | self.demand_eqtype_with_origin(&self.misc(sp), expected, actual) |
5bcae85e SL |
85 | } |
86 | ||
dfeec247 XL |
87 | pub fn demand_eqtype_with_origin( |
88 | &self, | |
89 | cause: &ObligationCause<'tcx>, | |
90 | expected: Ty<'tcx>, | |
91 | actual: Ty<'tcx>, | |
92 | ) -> Option<DiagnosticBuilder<'tcx>> { | |
7cac9316 | 93 | match self.at(cause, self.param_env).eq(expected, actual) { |
476ff2be SL |
94 | Ok(InferOk { obligations, value: () }) => { |
95 | self.register_predicates(obligations); | |
32a655c1 | 96 | None |
3b2f2976 | 97 | } |
dfeec247 | 98 | Err(e) => Some(self.report_mismatched_types(cause, expected, actual, e)), |
54a0048b | 99 | } |
1a4d82fc | 100 | } |
1a4d82fc | 101 | |
dfeec247 | 102 | pub fn demand_coerce( |
e74abb32 | 103 | &self, |
dfeec247 XL |
104 | expr: &hir::Expr<'_>, |
105 | checked_ty: Ty<'tcx>, | |
e74abb32 | 106 | expected: Ty<'tcx>, |
f035d41b | 107 | expected_ty_expr: Option<&'tcx hir::Expr<'tcx>>, |
dfeec247 XL |
108 | allow_two_phase: AllowTwoPhase, |
109 | ) -> Ty<'tcx> { | |
f035d41b XL |
110 | let (ty, err) = |
111 | self.demand_coerce_diag(expr, checked_ty, expected, expected_ty_expr, allow_two_phase); | |
abe05a73 | 112 | if let Some(mut err) = err { |
041b39d2 XL |
113 | err.emit(); |
114 | } | |
abe05a73 | 115 | ty |
041b39d2 XL |
116 | } |
117 | ||
a7813a04 | 118 | // Checks that the type of `expr` can be coerced to `expected`. |
cc61c64b | 119 | // |
0731742a | 120 | // N.B., this code relies on `self.diverges` to be accurate. In |
cc61c64b XL |
121 | // particular, assignments to `!` will be permitted if the |
122 | // diverges flag is currently "always". | |
60c5eb7d XL |
123 | pub fn demand_coerce_diag( |
124 | &self, | |
dfeec247 | 125 | expr: &hir::Expr<'_>, |
60c5eb7d XL |
126 | checked_ty: Ty<'tcx>, |
127 | expected: Ty<'tcx>, | |
f035d41b | 128 | expected_ty_expr: Option<&'tcx hir::Expr<'tcx>>, |
60c5eb7d XL |
129 | allow_two_phase: AllowTwoPhase, |
130 | ) -> (Ty<'tcx>, Option<DiagnosticBuilder<'tcx>>) { | |
e74abb32 | 131 | let expected = self.resolve_vars_with_obligations(expected); |
cc61c64b | 132 | |
83c7162d | 133 | let e = match self.try_coerce(expr, checked_ty, expected, allow_two_phase) { |
abe05a73 | 134 | Ok(ty) => return (ty, None), |
dfeec247 | 135 | Err(e) => e, |
abe05a73 XL |
136 | }; |
137 | ||
e74abb32 | 138 | let expr = expr.peel_drop_temps(); |
abe05a73 | 139 | let cause = self.misc(expr.span); |
e74abb32 | 140 | let expr_ty = self.resolve_vars_with_obligations(checked_ty); |
abe05a73 XL |
141 | let mut err = self.report_mismatched_types(&cause, expected, expr_ty, e); |
142 | ||
532ac7d7 XL |
143 | if self.is_assign_to_bool(expr, expected) { |
144 | // Error reported in `check_assign` so avoid emitting error again. | |
145 | err.delay_as_bug(); | |
dfeec247 | 146 | return (expected, None); |
abe05a73 | 147 | } |
3b2f2976 | 148 | |
f035d41b | 149 | self.emit_coerce_suggestions(&mut err, expr, expr_ty, expected, expected_ty_expr); |
8faf50e0 | 150 | |
abe05a73 | 151 | (expected, Some(err)) |
32a655c1 SL |
152 | } |
153 | ||
dfeec247 XL |
154 | fn annotate_expected_due_to_let_ty( |
155 | &self, | |
156 | err: &mut DiagnosticBuilder<'_>, | |
157 | expr: &hir::Expr<'_>, | |
158 | ) { | |
60c5eb7d | 159 | let parent = self.tcx.hir().get_parent_node(expr.hir_id); |
dfeec247 XL |
160 | if let Some(hir::Node::Local(hir::Local { ty: Some(ty), init: Some(init), .. })) = |
161 | self.tcx.hir().find(parent) | |
162 | { | |
60c5eb7d XL |
163 | if init.hir_id == expr.hir_id { |
164 | // Point at `let` assignment type. | |
165 | err.span_label(ty.span, "expected due to this"); | |
166 | } | |
167 | } | |
168 | } | |
169 | ||
532ac7d7 | 170 | /// Returns whether the expected type is `bool` and the expression is `x = y`. |
dfeec247 | 171 | pub fn is_assign_to_bool(&self, expr: &hir::Expr<'_>, expected: Ty<'tcx>) -> bool { |
e74abb32 | 172 | if let hir::ExprKind::Assign(..) = expr.kind { |
532ac7d7 XL |
173 | return expected == self.tcx.types.bool; |
174 | } | |
175 | false | |
176 | } | |
177 | ||
178 | /// If the expected type is an enum (Issue #55250) with any variants whose | |
179 | /// sole field is of the found type, suggest such variants. (Issue #42764) | |
180 | fn suggest_compatible_variants( | |
181 | &self, | |
182 | err: &mut DiagnosticBuilder<'_>, | |
dfeec247 | 183 | expr: &hir::Expr<'_>, |
532ac7d7 XL |
184 | expected: Ty<'tcx>, |
185 | expr_ty: Ty<'tcx>, | |
186 | ) { | |
e74abb32 | 187 | if let ty::Adt(expected_adt, substs) = expected.kind { |
532ac7d7 XL |
188 | if !expected_adt.is_enum() { |
189 | return; | |
190 | } | |
191 | ||
dfeec247 XL |
192 | let mut compatible_variants = expected_adt |
193 | .variants | |
532ac7d7 XL |
194 | .iter() |
195 | .filter(|variant| variant.fields.len() == 1) | |
196 | .filter_map(|variant| { | |
197 | let sole_field = &variant.fields[0]; | |
198 | let sole_field_ty = sole_field.ty(self.tcx, substs); | |
199 | if self.can_coerce(expr_ty, sole_field_ty) { | |
200 | let variant_path = self.tcx.def_path_str(variant.def_id); | |
201 | // FIXME #56861: DRYer prelude filtering | |
202 | Some(variant_path.trim_start_matches("std::prelude::v1::").to_string()) | |
203 | } else { | |
204 | None | |
205 | } | |
dfeec247 XL |
206 | }) |
207 | .peekable(); | |
532ac7d7 XL |
208 | |
209 | if compatible_variants.peek().is_some() { | |
ba9703b0 XL |
210 | if let Ok(expr_text) = self.tcx.sess.source_map().span_to_snippet(expr.span) { |
211 | let suggestions = compatible_variants.map(|v| format!("{}({})", v, expr_text)); | |
212 | let msg = "try using a variant of the expected enum"; | |
213 | err.span_suggestions( | |
214 | expr.span, | |
215 | msg, | |
216 | suggestions, | |
217 | Applicability::MaybeIncorrect, | |
218 | ); | |
219 | } | |
532ac7d7 XL |
220 | } |
221 | } | |
222 | } | |
223 | ||
dfeec247 XL |
224 | pub fn get_conversion_methods( |
225 | &self, | |
226 | span: Span, | |
227 | expected: Ty<'tcx>, | |
228 | checked_ty: Ty<'tcx>, | |
ba9703b0 | 229 | hir_id: hir::HirId, |
dfeec247 | 230 | ) -> Vec<AssocItem> { |
ba9703b0 XL |
231 | let mut methods = |
232 | self.probe_for_return_type(span, probe::Mode::MethodCall, expected, checked_ty, hir_id); | |
2c00a5a8 | 233 | methods.retain(|m| { |
ba9703b0 | 234 | self.has_only_self_parameter(m) |
dfeec247 XL |
235 | && self |
236 | .tcx | |
237 | .get_attrs(m.def_id) | |
238 | .iter() | |
f035d41b | 239 | // This special internal attribute is used to permit |
dfeec247 XL |
240 | // "identity-like" conversion methods to be suggested here. |
241 | // | |
242 | // FIXME (#46459 and #46460): ideally | |
243 | // `std::convert::Into::into` and `std::borrow:ToOwned` would | |
244 | // also be `#[rustc_conversion_suggestion]`, if not for | |
245 | // method-probing false-positives and -negatives (respectively). | |
246 | // | |
247 | // FIXME? Other potential candidate methods: `as_ref` and | |
248 | // `as_mut`? | |
74b04a01 | 249 | .any(|a| a.check_name(sym::rustc_conversion_suggestion)) |
2c00a5a8 | 250 | }); |
32a655c1 | 251 | |
2c00a5a8 | 252 | methods |
32a655c1 SL |
253 | } |
254 | ||
ba9703b0 XL |
255 | /// This function checks whether the method is not static and does not accept other parameters than `self`. |
256 | fn has_only_self_parameter(&self, method: &AssocItem) -> bool { | |
48663c56 | 257 | match method.kind { |
ba9703b0 XL |
258 | ty::AssocKind::Fn => { |
259 | method.fn_has_self_parameter | |
260 | && self.tcx.fn_sig(method.def_id).inputs().skip_binder().len() == 1 | |
32a655c1 SL |
261 | } |
262 | _ => false, | |
a7813a04 XL |
263 | } |
264 | } | |
cc61c64b | 265 | |
94b46f34 XL |
266 | /// Identify some cases where `as_ref()` would be appropriate and suggest it. |
267 | /// | |
268 | /// Given the following code: | |
269 | /// ``` | |
270 | /// struct Foo; | |
271 | /// fn takes_ref(_: &Foo) {} | |
272 | /// let ref opt = Some(Foo); | |
273 | /// | |
e1599b0c | 274 | /// opt.map(|param| takes_ref(param)); |
94b46f34 | 275 | /// ``` |
e1599b0c | 276 | /// Suggest using `opt.as_ref().map(|param| takes_ref(param));` instead. |
94b46f34 XL |
277 | /// |
278 | /// It only checks for `Option` and `Result` and won't work with | |
279 | /// ``` | |
e1599b0c | 280 | /// opt.map(|param| { takes_ref(param) }); |
94b46f34 | 281 | /// ``` |
dfeec247 | 282 | fn can_use_as_ref(&self, expr: &hir::Expr<'_>) -> Option<(Span, &'static str, String)> { |
e74abb32 | 283 | let path = match expr.kind { |
416331ca | 284 | hir::ExprKind::Path(hir::QPath::Resolved(_, ref path)) => path, |
dfeec247 | 285 | _ => return None, |
416331ca XL |
286 | }; |
287 | ||
288 | let local_id = match path.res { | |
289 | hir::def::Res::Local(id) => id, | |
dfeec247 | 290 | _ => return None, |
416331ca XL |
291 | }; |
292 | ||
293 | let local_parent = self.tcx.hir().get_parent_node(local_id); | |
e1599b0c XL |
294 | let param_hir_id = match self.tcx.hir().find(local_parent) { |
295 | Some(Node::Param(hir::Param { hir_id, .. })) => hir_id, | |
dfeec247 | 296 | _ => return None, |
416331ca XL |
297 | }; |
298 | ||
e1599b0c XL |
299 | let param_parent = self.tcx.hir().get_parent_node(*param_hir_id); |
300 | let (expr_hir_id, closure_fn_decl) = match self.tcx.hir().find(param_parent) { | |
dfeec247 XL |
301 | Some(Node::Expr(hir::Expr { |
302 | hir_id, | |
303 | kind: hir::ExprKind::Closure(_, decl, ..), | |
304 | .. | |
305 | })) => (hir_id, decl), | |
306 | _ => return None, | |
416331ca XL |
307 | }; |
308 | ||
309 | let expr_parent = self.tcx.hir().get_parent_node(*expr_hir_id); | |
310 | let hir = self.tcx.hir().find(expr_parent); | |
311 | let closure_params_len = closure_fn_decl.inputs.len(); | |
312 | let (method_path, method_span, method_expr) = match (hir, closure_params_len) { | |
dfeec247 XL |
313 | ( |
314 | Some(Node::Expr(hir::Expr { | |
f035d41b | 315 | kind: hir::ExprKind::MethodCall(path, span, expr, _), |
dfeec247 XL |
316 | .. |
317 | })), | |
318 | 1, | |
319 | ) => (path, span, expr), | |
320 | _ => return None, | |
416331ca XL |
321 | }; |
322 | ||
323 | let self_ty = self.tables.borrow().node_type(method_expr[0].hir_id); | |
324 | let self_ty = format!("{:?}", self_ty); | |
325 | let name = method_path.ident.as_str(); | |
dfeec247 XL |
326 | let is_as_ref_able = (self_ty.starts_with("&std::option::Option") |
327 | || self_ty.starts_with("&std::result::Result") | |
328 | || self_ty.starts_with("std::option::Option") | |
329 | || self_ty.starts_with("std::result::Result")) | |
330 | && (name == "map" || name == "and_then"); | |
416331ca XL |
331 | match (is_as_ref_able, self.sess().source_map().span_to_snippet(*method_span)) { |
332 | (true, Ok(src)) => { | |
333 | let suggestion = format!("as_ref().{}", src); | |
334 | Some((*method_span, "consider using `as_ref` instead", suggestion)) | |
dfeec247 XL |
335 | } |
336 | _ => None, | |
94b46f34 | 337 | } |
94b46f34 XL |
338 | } |
339 | ||
dc9dc135 XL |
340 | crate fn is_hir_id_from_struct_pattern_shorthand_field( |
341 | &self, | |
342 | hir_id: hir::HirId, | |
343 | sp: Span, | |
344 | ) -> bool { | |
74b04a01 | 345 | let sm = self.sess().source_map(); |
dc9dc135 XL |
346 | let parent_id = self.tcx.hir().get_parent_node(hir_id); |
347 | if let Some(parent) = self.tcx.hir().find(parent_id) { | |
532ac7d7 | 348 | // Account for fields |
dfeec247 XL |
349 | if let Node::Expr(hir::Expr { kind: hir::ExprKind::Struct(_, fields, ..), .. }) = parent |
350 | { | |
74b04a01 | 351 | if let Ok(src) = sm.span_to_snippet(sp) { |
dfeec247 | 352 | for field in *fields { |
60c5eb7d | 353 | if field.ident.as_str() == src && field.is_shorthand { |
532ac7d7 XL |
354 | return true; |
355 | } | |
356 | } | |
357 | } | |
358 | } | |
359 | } | |
360 | false | |
361 | } | |
362 | ||
f9f354fc XL |
363 | fn replace_prefix<A, B, C>(&self, s: A, old: B, new: C) -> Option<String> |
364 | where | |
365 | A: AsRef<str>, | |
366 | B: AsRef<str>, | |
367 | C: AsRef<str>, | |
368 | { | |
369 | let s = s.as_ref(); | |
370 | let old = old.as_ref(); | |
371 | if s.starts_with(old) { Some(new.as_ref().to_owned() + &s[old.len()..]) } else { None } | |
372 | } | |
373 | ||
cc61c64b XL |
374 | /// This function is used to determine potential "simple" improvements or users' errors and |
375 | /// provide them useful help. For example: | |
376 | /// | |
377 | /// ``` | |
378 | /// fn some_fn(s: &str) {} | |
379 | /// | |
380 | /// let x = "hey!".to_owned(); | |
381 | /// some_fn(x); // error | |
382 | /// ``` | |
383 | /// | |
384 | /// No need to find every potential function which could make a coercion to transform a | |
385 | /// `String` into a `&str` since a `&` would do the trick! | |
386 | /// | |
387 | /// In addition of this check, it also checks between references mutability state. If the | |
388 | /// expected is mutable but the provided isn't, maybe we could just say "Hey, try with | |
389 | /// `&mut`!". | |
dc9dc135 XL |
390 | pub fn check_ref( |
391 | &self, | |
dfeec247 | 392 | expr: &hir::Expr<'_>, |
dc9dc135 XL |
393 | checked_ty: Ty<'tcx>, |
394 | expected: Ty<'tcx>, | |
f9f354fc | 395 | ) -> Option<(Span, &'static str, String, Applicability)> { |
74b04a01 | 396 | let sm = self.sess().source_map(); |
532ac7d7 | 397 | let sp = expr.span; |
ba9703b0 | 398 | if sm.is_imported(sp) { |
532ac7d7 XL |
399 | // Ignore if span is from within a macro #41858, #58298. We previously used the macro |
400 | // call span, but that breaks down when the type error comes from multiple calls down. | |
8faf50e0 XL |
401 | return None; |
402 | } | |
403 | ||
dfeec247 XL |
404 | let is_struct_pat_shorthand_field = |
405 | self.is_hir_id_from_struct_pattern_shorthand_field(expr.hir_id, sp); | |
532ac7d7 | 406 | |
e1599b0c XL |
407 | // If the span is from a macro, then it's hard to extract the text |
408 | // and make a good suggestion, so don't bother. | |
e74abb32 XL |
409 | let is_macro = sp.from_expansion() && sp.desugaring_kind().is_none(); |
410 | ||
411 | // `ExprKind::DropTemps` is semantically irrelevant for these suggestions. | |
412 | let expr = expr.peel_drop_temps(); | |
48663c56 | 413 | |
e74abb32 XL |
414 | match (&expr.kind, &expected.kind, &checked_ty.kind) { |
415 | (_, &ty::Ref(_, exp, _), &ty::Ref(_, check, _)) => match (&exp.kind, &check.kind) { | |
ba9703b0 | 416 | (&ty::Str, &ty::Array(arr, _) | &ty::Slice(arr)) if arr == self.tcx.types.u8 => { |
e74abb32 | 417 | if let hir::ExprKind::Lit(_) = expr.kind { |
74b04a01 | 418 | if let Ok(src) = sm.span_to_snippet(sp) { |
f9f354fc | 419 | if let Some(src) = self.replace_prefix(src, "b\"", "\"") { |
dfeec247 XL |
420 | return Some(( |
421 | sp, | |
422 | "consider removing the leading `b`", | |
f9f354fc XL |
423 | src, |
424 | Applicability::MachineApplicable, | |
dfeec247 | 425 | )); |
8faf50e0 | 426 | } |
ea8adc8c XL |
427 | } |
428 | } | |
dfeec247 | 429 | } |
ba9703b0 | 430 | (&ty::Array(arr, _) | &ty::Slice(arr), &ty::Str) if arr == self.tcx.types.u8 => { |
e74abb32 | 431 | if let hir::ExprKind::Lit(_) = expr.kind { |
74b04a01 | 432 | if let Ok(src) = sm.span_to_snippet(sp) { |
f9f354fc | 433 | if let Some(src) = self.replace_prefix(src, "\"", "b\"") { |
dfeec247 XL |
434 | return Some(( |
435 | sp, | |
436 | "consider adding a leading `b`", | |
f9f354fc XL |
437 | src, |
438 | Applicability::MachineApplicable, | |
dfeec247 | 439 | )); |
8faf50e0 | 440 | } |
ea8adc8c XL |
441 | } |
442 | } | |
ea8adc8c | 443 | } |
94b46f34 | 444 | _ => {} |
ea8adc8c | 445 | }, |
48663c56 | 446 | (_, &ty::Ref(_, _, mutability), _) => { |
cc61c64b XL |
447 | // Check if it can work when put into a ref. For example: |
448 | // | |
449 | // ``` | |
450 | // fn bar(x: &mut i32) {} | |
451 | // | |
452 | // let x = 0u32; | |
453 | // bar(&x); // error, expected &mut | |
454 | // ``` | |
94b46f34 | 455 | let ref_ty = match mutability { |
dfeec247 | 456 | hir::Mutability::Mut => { |
532ac7d7 XL |
457 | self.tcx.mk_mut_ref(self.tcx.mk_region(ty::ReStatic), checked_ty) |
458 | } | |
dfeec247 | 459 | hir::Mutability::Not => { |
532ac7d7 XL |
460 | self.tcx.mk_imm_ref(self.tcx.mk_region(ty::ReStatic), checked_ty) |
461 | } | |
cc61c64b XL |
462 | }; |
463 | if self.can_coerce(ref_ty, expected) { | |
dc9dc135 | 464 | let mut sugg_sp = sp; |
f035d41b | 465 | if let hir::ExprKind::MethodCall(ref segment, sp, ref args, _) = expr.kind { |
f9f354fc | 466 | let clone_trait = self.tcx.require_lang_item(CloneTraitLangItem, Some(sp)); |
60c5eb7d | 467 | if let ([arg], Some(true), sym::clone) = ( |
dc9dc135 XL |
468 | &args[..], |
469 | self.tables.borrow().type_dependent_def_id(expr.hir_id).map(|did| { | |
470 | let ai = self.tcx.associated_item(did); | |
471 | ai.container == ty::TraitContainer(clone_trait) | |
472 | }), | |
60c5eb7d | 473 | segment.ident.name, |
dc9dc135 XL |
474 | ) { |
475 | // If this expression had a clone call when suggesting borrowing | |
60c5eb7d | 476 | // we want to suggest removing it because it'd now be unnecessary. |
dc9dc135 XL |
477 | sugg_sp = arg.span; |
478 | } | |
479 | } | |
74b04a01 | 480 | if let Ok(src) = sm.span_to_snippet(sugg_sp) { |
e74abb32 | 481 | let needs_parens = match expr.kind { |
0bf4aa26 | 482 | // parenthesize if needed (Issue #46756) |
dfeec247 | 483 | hir::ExprKind::Cast(_, _) | hir::ExprKind::Binary(_, _, _) => true, |
0bf4aa26 | 484 | // parenthesize borrows of range literals (Issue #54505) |
dfeec247 | 485 | _ if is_range_literal(self.tcx.sess.source_map(), expr) => true, |
0bf4aa26 XL |
486 | _ => false, |
487 | }; | |
dfeec247 | 488 | let sugg_expr = if needs_parens { format!("({})", src) } else { src }; |
0bf4aa26 | 489 | |
94b46f34 | 490 | if let Some(sugg) = self.can_use_as_ref(expr) { |
f9f354fc XL |
491 | return Some(( |
492 | sugg.0, | |
493 | sugg.1, | |
494 | sugg.2, | |
495 | Applicability::MachineApplicable, | |
496 | )); | |
94b46f34 | 497 | } |
532ac7d7 XL |
498 | let field_name = if is_struct_pat_shorthand_field { |
499 | format!("{}: ", sugg_expr) | |
500 | } else { | |
501 | String::new() | |
502 | }; | |
dc9dc135 | 503 | if let Some(hir::Node::Expr(hir::Expr { |
dfeec247 | 504 | kind: hir::ExprKind::Assign(left_expr, ..), |
dc9dc135 | 505 | .. |
dfeec247 XL |
506 | })) = self.tcx.hir().find(self.tcx.hir().get_parent_node(expr.hir_id)) |
507 | { | |
508 | if mutability == hir::Mutability::Mut { | |
dc9dc135 XL |
509 | // Found the following case: |
510 | // fn foo(opt: &mut Option<String>){ opt = None } | |
511 | // --- ^^^^ | |
512 | // | | | |
513 | // consider dereferencing here: `*opt` | | |
514 | // expected mutable reference, found enum `Option` | |
74b04a01 | 515 | if let Ok(src) = sm.span_to_snippet(left_expr.span) { |
dc9dc135 XL |
516 | return Some(( |
517 | left_expr.span, | |
518 | "consider dereferencing here to assign to the mutable \ | |
519 | borrowed piece of memory", | |
520 | format!("*{}", src), | |
f9f354fc | 521 | Applicability::MachineApplicable, |
dc9dc135 XL |
522 | )); |
523 | } | |
524 | } | |
525 | } | |
526 | ||
94b46f34 | 527 | return Some(match mutability { |
dfeec247 | 528 | hir::Mutability::Mut => ( |
532ac7d7 XL |
529 | sp, |
530 | "consider mutably borrowing here", | |
531 | format!("{}&mut {}", field_name, sugg_expr), | |
f9f354fc | 532 | Applicability::MachineApplicable, |
532ac7d7 | 533 | ), |
dfeec247 | 534 | hir::Mutability::Not => ( |
532ac7d7 XL |
535 | sp, |
536 | "consider borrowing here", | |
537 | format!("{}&{}", field_name, sugg_expr), | |
f9f354fc | 538 | Applicability::MachineApplicable, |
532ac7d7 | 539 | ), |
ff7c6d11 | 540 | }); |
cc61c64b XL |
541 | } |
542 | } | |
dfeec247 | 543 | } |
60c5eb7d XL |
544 | ( |
545 | hir::ExprKind::AddrOf(hir::BorrowKind::Ref, _, ref expr), | |
546 | _, | |
dfeec247 | 547 | &ty::Ref(_, checked, _), |
60c5eb7d | 548 | ) if { |
48663c56 | 549 | self.infcx.can_sub(self.param_env, checked, &expected).is_ok() && !is_macro |
dfeec247 XL |
550 | } => |
551 | { | |
ea8adc8c | 552 | // We have `&T`, check if what was expected was `T`. If so, |
48663c56 | 553 | // we may want to suggest removing a `&`. |
ba9703b0 | 554 | if sm.is_imported(expr.span) { |
f9f354fc XL |
555 | if let Ok(src) = sm.span_to_snippet(sp) { |
556 | if let Some(src) = self.replace_prefix(src, "&", "") { | |
48663c56 XL |
557 | return Some(( |
558 | sp, | |
559 | "consider removing the borrow", | |
f9f354fc XL |
560 | src, |
561 | Applicability::MachineApplicable, | |
48663c56 | 562 | )); |
2c00a5a8 | 563 | } |
ea8adc8c | 564 | } |
48663c56 | 565 | return None; |
ea8adc8c | 566 | } |
74b04a01 | 567 | if let Ok(code) = sm.span_to_snippet(expr.span) { |
f9f354fc XL |
568 | return Some(( |
569 | sp, | |
570 | "consider removing the borrow", | |
571 | code, | |
572 | Applicability::MachineApplicable, | |
573 | )); | |
574 | } | |
575 | } | |
576 | ( | |
577 | _, | |
578 | &ty::RawPtr(TypeAndMut { ty: ty_b, mutbl: mutbl_b }), | |
579 | &ty::Ref(_, ty_a, mutbl_a), | |
580 | ) => { | |
581 | if let Some(steps) = self.deref_steps(ty_a, ty_b) { | |
582 | // Only suggest valid if dereferencing needed. | |
583 | if steps > 0 { | |
584 | // The pointer type implements `Copy` trait so the suggestion is always valid. | |
585 | if let Ok(src) = sm.span_to_snippet(sp) { | |
586 | let derefs = &"*".repeat(steps); | |
587 | if let Some((src, applicability)) = match mutbl_b { | |
588 | hir::Mutability::Mut => { | |
589 | let new_prefix = "&mut ".to_owned() + derefs; | |
590 | match mutbl_a { | |
591 | hir::Mutability::Mut => { | |
592 | if let Some(s) = | |
593 | self.replace_prefix(src, "&mut ", new_prefix) | |
594 | { | |
595 | Some((s, Applicability::MachineApplicable)) | |
596 | } else { | |
597 | None | |
598 | } | |
599 | } | |
600 | hir::Mutability::Not => { | |
601 | if let Some(s) = | |
602 | self.replace_prefix(src, "&", new_prefix) | |
603 | { | |
604 | Some((s, Applicability::Unspecified)) | |
605 | } else { | |
606 | None | |
607 | } | |
608 | } | |
609 | } | |
610 | } | |
611 | hir::Mutability::Not => { | |
612 | let new_prefix = "&".to_owned() + derefs; | |
613 | match mutbl_a { | |
614 | hir::Mutability::Mut => { | |
615 | if let Some(s) = | |
616 | self.replace_prefix(src, "&mut ", new_prefix) | |
617 | { | |
618 | Some((s, Applicability::MachineApplicable)) | |
619 | } else { | |
620 | None | |
621 | } | |
622 | } | |
623 | hir::Mutability::Not => { | |
624 | if let Some(s) = | |
625 | self.replace_prefix(src, "&", new_prefix) | |
626 | { | |
627 | Some((s, Applicability::MachineApplicable)) | |
628 | } else { | |
629 | None | |
630 | } | |
631 | } | |
632 | } | |
633 | } | |
634 | } { | |
635 | return Some((sp, "consider dereferencing", src, applicability)); | |
636 | } | |
637 | } | |
638 | } | |
9fa01778 | 639 | } |
dfeec247 | 640 | } |
48663c56 | 641 | _ if sp == expr.span && !is_macro => { |
f9f354fc XL |
642 | if let Some(steps) = self.deref_steps(checked_ty, expected) { |
643 | if steps == 1 { | |
644 | // For a suggestion to make sense, the type would need to be `Copy`. | |
645 | if self.infcx.type_is_copy_modulo_regions(self.param_env, expected, sp) { | |
646 | if let Ok(code) = sm.span_to_snippet(sp) { | |
647 | let message = if checked_ty.is_region_ptr() { | |
648 | "consider dereferencing the borrow" | |
649 | } else { | |
650 | "consider dereferencing the type" | |
651 | }; | |
652 | let suggestion = if is_struct_pat_shorthand_field { | |
653 | format!("{}: *{}", code, code) | |
654 | } else { | |
655 | format!("*{}", code) | |
656 | }; | |
657 | return Some(( | |
658 | sp, | |
659 | message, | |
660 | suggestion, | |
661 | Applicability::MachineApplicable, | |
662 | )); | |
663 | } | |
664 | } | |
0bf4aa26 XL |
665 | } |
666 | } | |
667 | } | |
0bf4aa26 XL |
668 | _ => {} |
669 | } | |
48663c56 | 670 | None |
0bf4aa26 XL |
671 | } |
672 | ||
9fa01778 XL |
673 | pub fn check_for_cast( |
674 | &self, | |
60c5eb7d | 675 | err: &mut DiagnosticBuilder<'_>, |
dfeec247 | 676 | expr: &hir::Expr<'_>, |
9fa01778 XL |
677 | checked_ty: Ty<'tcx>, |
678 | expected_ty: Ty<'tcx>, | |
f035d41b | 679 | expected_ty_expr: Option<&'tcx hir::Expr<'tcx>>, |
9fa01778 | 680 | ) -> bool { |
ba9703b0 | 681 | if self.tcx.sess.source_map().is_imported(expr.span) { |
e1599b0c XL |
682 | // Ignore if span is from within a macro. |
683 | return false; | |
684 | } | |
2c00a5a8 | 685 | |
f035d41b XL |
686 | let src = if let Ok(src) = self.tcx.sess.source_map().span_to_snippet(expr.span) { |
687 | src | |
688 | } else { | |
689 | return false; | |
690 | }; | |
691 | ||
2c00a5a8 XL |
692 | // If casting this expression to a given numeric type would be appropriate in case of a type |
693 | // mismatch. | |
694 | // | |
695 | // We want to minimize the amount of casting operations that are suggested, as it can be a | |
696 | // lossy operation with potentially bad side effects, so we only suggest when encountering | |
697 | // an expression that indicates that the original type couldn't be directly changed. | |
698 | // | |
699 | // For now, don't suggest casting with `as`. | |
700 | let can_cast = false; | |
701 | ||
f9f354fc XL |
702 | let prefix = if let Some(hir::Node::Expr(hir::Expr { |
703 | kind: hir::ExprKind::Struct(_, fields, _), | |
704 | .. | |
dfeec247 XL |
705 | })) = self.tcx.hir().find(self.tcx.hir().get_parent_node(expr.hir_id)) |
706 | { | |
9fa01778 | 707 | // `expr` is a literal field for a struct, only suggest if appropriate |
f9f354fc XL |
708 | match (*fields) |
709 | .iter() | |
710 | .find(|field| field.expr.hir_id == expr.hir_id && field.is_shorthand) | |
711 | { | |
712 | // This is a field literal | |
713 | Some(field) => format!("{}: ", field.ident), | |
9fa01778 | 714 | // Likely a field was meant, but this field wasn't found. Do not suggest anything. |
f9f354fc | 715 | None => return false, |
9fa01778 | 716 | } |
f9f354fc XL |
717 | } else { |
718 | String::new() | |
719 | }; | |
f035d41b | 720 | |
e74abb32 | 721 | if let hir::ExprKind::Call(path, args) = &expr.kind { |
dfeec247 XL |
722 | if let (hir::ExprKind::Path(hir::QPath::TypeRelative(base_ty, path_segment)), 1) = |
723 | (&path.kind, args.len()) | |
724 | { | |
e1599b0c | 725 | // `expr` is a conversion like `u32::from(val)`, do not suggest anything (#63697). |
dfeec247 XL |
726 | if let (hir::TyKind::Path(hir::QPath::Resolved(None, base_ty_path)), sym::from) = |
727 | (&base_ty.kind, path_segment.ident.name) | |
728 | { | |
e1599b0c XL |
729 | if let Some(ident) = &base_ty_path.segments.iter().map(|s| s.ident).next() { |
730 | match ident.name { | |
dfeec247 XL |
731 | sym::i128 |
732 | | sym::i64 | |
733 | | sym::i32 | |
734 | | sym::i16 | |
735 | | sym::i8 | |
736 | | sym::u128 | |
737 | | sym::u64 | |
738 | | sym::u32 | |
739 | | sym::u16 | |
740 | | sym::u8 | |
741 | | sym::isize | |
742 | | sym::usize | |
743 | if base_ty_path.segments.len() == 1 => | |
744 | { | |
e1599b0c XL |
745 | return false; |
746 | } | |
747 | _ => {} | |
748 | } | |
749 | } | |
750 | } | |
751 | } | |
752 | } | |
9fa01778 | 753 | |
48663c56 XL |
754 | let msg = format!("you can convert an `{}` to `{}`", checked_ty, expected_ty); |
755 | let cast_msg = format!("you can cast an `{} to `{}`", checked_ty, expected_ty); | |
48663c56 XL |
756 | let lit_msg = format!( |
757 | "change the type of the numeric literal from `{}` to `{}`", | |
dfeec247 | 758 | checked_ty, expected_ty, |
48663c56 XL |
759 | ); |
760 | ||
f035d41b XL |
761 | let with_opt_paren: fn(&dyn fmt::Display) -> String = |
762 | if expr.precedence().order() < PREC_POSTFIX { | |
763 | |s| format!("({})", s) | |
764 | } else { | |
765 | |s| s.to_string() | |
766 | }; | |
767 | ||
768 | let cast_suggestion = format!("{}{} as {}", prefix, with_opt_paren(&src), expected_ty); | |
769 | let into_suggestion = format!("{}{}.into()", prefix, with_opt_paren(&src)); | |
770 | let suffix_suggestion = with_opt_paren(&format_args!( | |
771 | "{}{}", | |
772 | if matches!( | |
773 | (&expected_ty.kind, &checked_ty.kind), | |
774 | (ty::Int(_) | ty::Uint(_), ty::Float(_)) | |
775 | ) { | |
776 | // Remove fractional part from literal, for example `42.0f32` into `42` | |
777 | let src = src.trim_end_matches(&checked_ty.to_string()); | |
778 | src.split('.').next().unwrap() | |
779 | } else { | |
780 | src.trim_end_matches(&checked_ty.to_string()) | |
781 | }, | |
782 | expected_ty, | |
783 | )); | |
784 | let literal_is_ty_suffixed = |expr: &hir::Expr<'_>| { | |
785 | if let hir::ExprKind::Lit(lit) = &expr.kind { lit.node.is_suffixed() } else { false } | |
786 | }; | |
787 | let is_negative_int = | |
788 | |expr: &hir::Expr<'_>| matches!(expr.kind, hir::ExprKind::Unary(hir::UnOp::UnNeg, ..)); | |
789 | let is_uint = |ty: Ty<'_>| matches!(ty.kind, ty::Uint(..)); | |
790 | ||
791 | let in_const_context = self.tcx.hir().is_inside_const_context(expr.hir_id); | |
792 | ||
793 | let suggest_fallible_into_or_lhs_from = | |
794 | |err: &mut DiagnosticBuilder<'_>, exp_to_found_is_fallible: bool| { | |
795 | // If we know the expression the expected type is derived from, we might be able | |
796 | // to suggest a widening conversion rather than a narrowing one (which may | |
797 | // panic). For example, given x: u8 and y: u32, if we know the span of "x", | |
798 | // x > y | |
799 | // can be given the suggestion "u32::from(x) > y" rather than | |
800 | // "x > y.try_into().unwrap()". | |
801 | let lhs_expr_and_src = expected_ty_expr.and_then(|expr| { | |
802 | match self.tcx.sess.source_map().span_to_snippet(expr.span).ok() { | |
803 | Some(src) => Some((expr, src)), | |
804 | None => None, | |
805 | } | |
806 | }); | |
807 | let (span, msg, suggestion) = if let (Some((lhs_expr, lhs_src)), false) = | |
808 | (lhs_expr_and_src, exp_to_found_is_fallible) | |
dfeec247 | 809 | { |
f035d41b XL |
810 | let msg = format!( |
811 | "you can convert `{}` from `{}` to `{}`, matching the type of `{}`", | |
812 | lhs_src, expected_ty, checked_ty, src | |
813 | ); | |
814 | let suggestion = format!("{}::from({})", checked_ty, lhs_src); | |
815 | (lhs_expr.span, msg, suggestion) | |
48663c56 | 816 | } else { |
f035d41b XL |
817 | let msg = format!("{} and panic if the converted value wouldn't fit", msg); |
818 | let suggestion = | |
819 | format!("{}{}.try_into().unwrap()", prefix, with_opt_paren(&src)); | |
820 | (expr.span, msg, suggestion) | |
821 | }; | |
822 | err.span_suggestion(span, &msg, suggestion, Applicability::MachineApplicable); | |
823 | }; | |
824 | ||
825 | let suggest_to_change_suffix_or_into = | |
826 | |err: &mut DiagnosticBuilder<'_>, | |
827 | found_to_exp_is_fallible: bool, | |
828 | exp_to_found_is_fallible: bool| { | |
829 | let always_fallible = found_to_exp_is_fallible | |
830 | && (exp_to_found_is_fallible || expected_ty_expr.is_none()); | |
831 | let msg = if literal_is_ty_suffixed(expr) { | |
832 | &lit_msg | |
833 | } else if always_fallible && (is_negative_int(expr) && is_uint(expected_ty)) { | |
834 | // We now know that converting either the lhs or rhs is fallible. Before we | |
835 | // suggest a fallible conversion, check if the value can never fit in the | |
836 | // expected type. | |
837 | let msg = format!("`{}` cannot fit into type `{}`", src, expected_ty); | |
838 | err.note(&msg); | |
839 | return; | |
840 | } else if in_const_context { | |
841 | // Do not recommend `into` or `try_into` in const contexts. | |
842 | return; | |
843 | } else if found_to_exp_is_fallible { | |
844 | return suggest_fallible_into_or_lhs_from(err, exp_to_found_is_fallible); | |
0bf4aa26 | 845 | } else { |
f035d41b XL |
846 | &msg |
847 | }; | |
848 | let suggestion = if literal_is_ty_suffixed(expr) { | |
849 | suffix_suggestion.clone() | |
850 | } else { | |
851 | into_suggestion.clone() | |
852 | }; | |
853 | err.span_suggestion(expr.span, msg, suggestion, Applicability::MachineApplicable); | |
0bf4aa26 XL |
854 | }; |
855 | ||
f035d41b XL |
856 | match (&expected_ty.kind, &checked_ty.kind) { |
857 | (&ty::Int(ref exp), &ty::Int(ref found)) => { | |
858 | let (f2e_is_fallible, e2f_is_fallible) = match (exp.bit_width(), found.bit_width()) | |
859 | { | |
860 | (Some(exp), Some(found)) if exp < found => (true, false), | |
861 | (Some(exp), Some(found)) if exp > found => (false, true), | |
862 | (None, Some(8 | 16)) => (false, true), | |
863 | (Some(8 | 16), None) => (true, false), | |
864 | (None, _) | (_, None) => (true, true), | |
865 | _ => (false, false), | |
866 | }; | |
867 | suggest_to_change_suffix_or_into(err, f2e_is_fallible, e2f_is_fallible); | |
868 | true | |
869 | } | |
870 | (&ty::Uint(ref exp), &ty::Uint(ref found)) => { | |
871 | let (f2e_is_fallible, e2f_is_fallible) = match (exp.bit_width(), found.bit_width()) | |
872 | { | |
873 | (Some(exp), Some(found)) if exp < found => (true, false), | |
874 | (Some(exp), Some(found)) if exp > found => (false, true), | |
875 | (None, Some(8 | 16)) => (false, true), | |
876 | (Some(8 | 16), None) => (true, false), | |
877 | (None, _) | (_, None) => (true, true), | |
878 | _ => (false, false), | |
879 | }; | |
880 | suggest_to_change_suffix_or_into(err, f2e_is_fallible, e2f_is_fallible); | |
881 | true | |
882 | } | |
883 | (&ty::Int(exp), &ty::Uint(found)) => { | |
884 | let (f2e_is_fallible, e2f_is_fallible) = match (exp.bit_width(), found.bit_width()) | |
885 | { | |
886 | (Some(exp), Some(found)) if found < exp => (false, true), | |
887 | (None, Some(8)) => (false, true), | |
888 | _ => (true, true), | |
889 | }; | |
890 | suggest_to_change_suffix_or_into(err, f2e_is_fallible, e2f_is_fallible); | |
891 | true | |
892 | } | |
893 | (&ty::Uint(exp), &ty::Int(found)) => { | |
894 | let (f2e_is_fallible, e2f_is_fallible) = match (exp.bit_width(), found.bit_width()) | |
895 | { | |
896 | (Some(exp), Some(found)) if found > exp => (true, false), | |
897 | (Some(8), None) => (true, false), | |
898 | _ => (true, true), | |
899 | }; | |
900 | suggest_to_change_suffix_or_into(err, f2e_is_fallible, e2f_is_fallible); | |
901 | true | |
902 | } | |
903 | (&ty::Float(ref exp), &ty::Float(ref found)) => { | |
904 | if found.bit_width() < exp.bit_width() { | |
905 | suggest_to_change_suffix_or_into(err, false, true); | |
906 | } else if literal_is_ty_suffixed(expr) { | |
dfeec247 XL |
907 | err.span_suggestion( |
908 | expr.span, | |
f035d41b XL |
909 | &lit_msg, |
910 | suffix_suggestion, | |
dfeec247 XL |
911 | Applicability::MachineApplicable, |
912 | ); | |
f035d41b XL |
913 | } else if can_cast { |
914 | // Missing try_into implementation for `f64` to `f32` | |
915 | err.span_suggestion( | |
916 | expr.span, | |
917 | &format!("{}, producing the closest possible value", cast_msg), | |
918 | cast_suggestion, | |
919 | Applicability::MaybeIncorrect, // lossy conversion | |
920 | ); | |
2c00a5a8 | 921 | } |
f035d41b XL |
922 | true |
923 | } | |
924 | (&ty::Uint(_) | &ty::Int(_), &ty::Float(_)) => { | |
925 | if literal_is_ty_suffixed(expr) { | |
926 | err.span_suggestion( | |
927 | expr.span, | |
928 | &lit_msg, | |
929 | suffix_suggestion, | |
930 | Applicability::MachineApplicable, | |
931 | ); | |
932 | } else if can_cast { | |
933 | // Missing try_into implementation for `{float}` to `{integer}` | |
934 | err.span_suggestion( | |
935 | expr.span, | |
936 | &format!("{}, rounding the float towards zero", msg), | |
937 | cast_suggestion, | |
938 | Applicability::MaybeIncorrect, // lossy conversion | |
939 | ); | |
2c00a5a8 | 940 | } |
f035d41b XL |
941 | true |
942 | } | |
943 | (&ty::Float(ref exp), &ty::Uint(ref found)) => { | |
944 | // if `found` is `None` (meaning found is `usize`), don't suggest `.into()` | |
945 | if exp.bit_width() > found.bit_width().unwrap_or(256) { | |
946 | err.span_suggestion( | |
947 | expr.span, | |
948 | &format!( | |
949 | "{}, producing the floating point representation of the integer", | |
950 | msg, | |
951 | ), | |
952 | into_suggestion, | |
953 | Applicability::MachineApplicable, | |
954 | ); | |
955 | } else if literal_is_ty_suffixed(expr) { | |
956 | err.span_suggestion( | |
957 | expr.span, | |
958 | &lit_msg, | |
959 | suffix_suggestion, | |
960 | Applicability::MachineApplicable, | |
961 | ); | |
962 | } else { | |
963 | // Missing try_into implementation for `{integer}` to `{float}` | |
964 | err.span_suggestion( | |
965 | expr.span, | |
966 | &format!( | |
967 | "{}, producing the floating point representation of the integer, | |
48663c56 | 968 | rounded if necessary", |
f035d41b XL |
969 | cast_msg, |
970 | ), | |
971 | cast_suggestion, | |
972 | Applicability::MaybeIncorrect, // lossy conversion | |
973 | ); | |
2c00a5a8 | 974 | } |
f035d41b XL |
975 | true |
976 | } | |
977 | (&ty::Float(ref exp), &ty::Int(ref found)) => { | |
978 | // if `found` is `None` (meaning found is `isize`), don't suggest `.into()` | |
979 | if exp.bit_width() > found.bit_width().unwrap_or(256) { | |
980 | err.span_suggestion( | |
981 | expr.span, | |
982 | &format!( | |
983 | "{}, producing the floating point representation of the integer", | |
984 | &msg, | |
985 | ), | |
986 | into_suggestion, | |
987 | Applicability::MachineApplicable, | |
988 | ); | |
989 | } else if literal_is_ty_suffixed(expr) { | |
990 | err.span_suggestion( | |
991 | expr.span, | |
992 | &lit_msg, | |
993 | suffix_suggestion, | |
994 | Applicability::MachineApplicable, | |
995 | ); | |
996 | } else { | |
997 | // Missing try_into implementation for `{integer}` to `{float}` | |
998 | err.span_suggestion( | |
999 | expr.span, | |
1000 | &format!( | |
1001 | "{}, producing the floating point representation of the integer, \ | |
1002 | rounded if necessary", | |
1003 | &msg, | |
1004 | ), | |
1005 | cast_suggestion, | |
1006 | Applicability::MaybeIncorrect, // lossy conversion | |
1007 | ); | |
2c00a5a8 | 1008 | } |
f035d41b | 1009 | true |
2c00a5a8 | 1010 | } |
f035d41b | 1011 | _ => false, |
2c00a5a8 XL |
1012 | } |
1013 | } | |
1a4d82fc | 1014 | } |