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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; | |
3dfed10e | 9 | use rustc_hir::lang_items::LangItem; |
ba9703b0 | 10 | use rustc_hir::{is_range_literal, Node}; |
17df50a5 | 11 | use rustc_middle::lint::in_external_macro; |
ba9703b0 | 12 | use rustc_middle::ty::adjustment::AllowTwoPhase; |
136023e0 | 13 | use rustc_middle::ty::print::with_no_trimmed_paths; |
f9f354fc | 14 | use rustc_middle::ty::{self, AssocItem, Ty, TypeAndMut}; |
dfeec247 XL |
15 | use rustc_span::symbol::sym; |
16 | use rustc_span::Span; | |
32a655c1 SL |
17 | |
18 | use super::method::probe; | |
1a4d82fc | 19 | |
f035d41b | 20 | use std::fmt; |
17df50a5 | 21 | use std::iter; |
f035d41b | 22 | |
dc9dc135 | 23 | impl<'a, 'tcx> FnCtxt<'a, 'tcx> { |
60c5eb7d XL |
24 | pub fn emit_coerce_suggestions( |
25 | &self, | |
26 | err: &mut DiagnosticBuilder<'_>, | |
dfeec247 | 27 | expr: &hir::Expr<'_>, |
60c5eb7d | 28 | expr_ty: Ty<'tcx>, |
dfeec247 | 29 | expected: Ty<'tcx>, |
f035d41b | 30 | expected_ty_expr: Option<&'tcx hir::Expr<'tcx>>, |
60c5eb7d XL |
31 | ) { |
32 | self.annotate_expected_due_to_let_ty(err, expr); | |
33 | self.suggest_compatible_variants(err, expr, expected, expr_ty); | |
f035d41b | 34 | self.suggest_deref_ref_or_into(err, expr, expected, expr_ty, expected_ty_expr); |
74b04a01 XL |
35 | if self.suggest_calling_boxed_future_when_appropriate(err, expr, expected, expr_ty) { |
36 | return; | |
37 | } | |
5869c6ff | 38 | self.suggest_no_capture_closure(err, expected, expr_ty); |
60c5eb7d | 39 | self.suggest_boxing_when_appropriate(err, expr, expected, expr_ty); |
3dfed10e | 40 | self.suggest_missing_parentheses(err, expr); |
f035d41b | 41 | self.note_need_for_fn_pointer(err, expected, expr_ty); |
3dfed10e | 42 | self.note_internal_mutation_in_method(err, expr, expected, expr_ty); |
cdc7bbd5 | 43 | self.report_closure_infered_return_type(err, expected) |
60c5eb7d XL |
44 | } |
45 | ||
a7813a04 XL |
46 | // Requires that the two types unify, and prints an error message if |
47 | // they don't. | |
48 | pub fn demand_suptype(&self, sp: Span, expected: Ty<'tcx>, actual: Ty<'tcx>) { | |
f9f354fc XL |
49 | if let Some(mut e) = self.demand_suptype_diag(sp, expected, actual) { |
50 | e.emit(); | |
51 | } | |
041b39d2 XL |
52 | } |
53 | ||
dfeec247 XL |
54 | pub fn demand_suptype_diag( |
55 | &self, | |
56 | sp: Span, | |
57 | expected: Ty<'tcx>, | |
58 | actual: Ty<'tcx>, | |
59 | ) -> Option<DiagnosticBuilder<'tcx>> { | |
74b04a01 XL |
60 | self.demand_suptype_with_origin(&self.misc(sp), expected, actual) |
61 | } | |
62 | ||
63 | pub fn demand_suptype_with_origin( | |
64 | &self, | |
65 | cause: &ObligationCause<'tcx>, | |
66 | expected: Ty<'tcx>, | |
67 | actual: Ty<'tcx>, | |
68 | ) -> Option<DiagnosticBuilder<'tcx>> { | |
7cac9316 | 69 | match self.at(cause, self.param_env).sup(expected, actual) { |
476ff2be SL |
70 | Ok(InferOk { obligations, value: () }) => { |
71 | self.register_predicates(obligations); | |
041b39d2 | 72 | None |
a7813a04 | 73 | } |
dfeec247 | 74 | Err(e) => Some(self.report_mismatched_types(&cause, expected, actual, e)), |
54a0048b | 75 | } |
1a4d82fc | 76 | } |
1a4d82fc | 77 | |
a7813a04 | 78 | pub fn demand_eqtype(&self, sp: Span, expected: Ty<'tcx>, actual: Ty<'tcx>) { |
32a655c1 SL |
79 | if let Some(mut err) = self.demand_eqtype_diag(sp, expected, actual) { |
80 | err.emit(); | |
81 | } | |
82 | } | |
83 | ||
dfeec247 XL |
84 | pub fn demand_eqtype_diag( |
85 | &self, | |
86 | sp: Span, | |
87 | expected: Ty<'tcx>, | |
88 | actual: Ty<'tcx>, | |
89 | ) -> Option<DiagnosticBuilder<'tcx>> { | |
32a655c1 | 90 | self.demand_eqtype_with_origin(&self.misc(sp), expected, actual) |
5bcae85e SL |
91 | } |
92 | ||
dfeec247 XL |
93 | pub fn demand_eqtype_with_origin( |
94 | &self, | |
95 | cause: &ObligationCause<'tcx>, | |
96 | expected: Ty<'tcx>, | |
97 | actual: Ty<'tcx>, | |
98 | ) -> Option<DiagnosticBuilder<'tcx>> { | |
7cac9316 | 99 | match self.at(cause, self.param_env).eq(expected, actual) { |
476ff2be SL |
100 | Ok(InferOk { obligations, value: () }) => { |
101 | self.register_predicates(obligations); | |
32a655c1 | 102 | None |
3b2f2976 | 103 | } |
dfeec247 | 104 | Err(e) => Some(self.report_mismatched_types(cause, expected, actual, e)), |
54a0048b | 105 | } |
1a4d82fc | 106 | } |
1a4d82fc | 107 | |
dfeec247 | 108 | pub fn demand_coerce( |
e74abb32 | 109 | &self, |
dfeec247 XL |
110 | expr: &hir::Expr<'_>, |
111 | checked_ty: Ty<'tcx>, | |
e74abb32 | 112 | expected: Ty<'tcx>, |
f035d41b | 113 | expected_ty_expr: Option<&'tcx hir::Expr<'tcx>>, |
dfeec247 XL |
114 | allow_two_phase: AllowTwoPhase, |
115 | ) -> Ty<'tcx> { | |
f035d41b XL |
116 | let (ty, err) = |
117 | self.demand_coerce_diag(expr, checked_ty, expected, expected_ty_expr, allow_two_phase); | |
abe05a73 | 118 | if let Some(mut err) = err { |
041b39d2 XL |
119 | err.emit(); |
120 | } | |
abe05a73 | 121 | ty |
041b39d2 XL |
122 | } |
123 | ||
1b1a35ee XL |
124 | /// Checks that the type of `expr` can be coerced to `expected`. |
125 | /// | |
126 | /// N.B., this code relies on `self.diverges` to be accurate. In particular, assignments to `!` | |
127 | /// will be permitted if the diverges flag is currently "always". | |
60c5eb7d XL |
128 | pub fn demand_coerce_diag( |
129 | &self, | |
dfeec247 | 130 | expr: &hir::Expr<'_>, |
60c5eb7d XL |
131 | checked_ty: Ty<'tcx>, |
132 | expected: Ty<'tcx>, | |
f035d41b | 133 | expected_ty_expr: Option<&'tcx hir::Expr<'tcx>>, |
60c5eb7d XL |
134 | allow_two_phase: AllowTwoPhase, |
135 | ) -> (Ty<'tcx>, Option<DiagnosticBuilder<'tcx>>) { | |
e74abb32 | 136 | let expected = self.resolve_vars_with_obligations(expected); |
cc61c64b | 137 | |
83c7162d | 138 | let e = match self.try_coerce(expr, checked_ty, expected, allow_two_phase) { |
abe05a73 | 139 | Ok(ty) => return (ty, None), |
dfeec247 | 140 | Err(e) => e, |
abe05a73 XL |
141 | }; |
142 | ||
e74abb32 | 143 | let expr = expr.peel_drop_temps(); |
abe05a73 | 144 | let cause = self.misc(expr.span); |
e74abb32 | 145 | let expr_ty = self.resolve_vars_with_obligations(checked_ty); |
abe05a73 XL |
146 | let mut err = self.report_mismatched_types(&cause, expected, expr_ty, e); |
147 | ||
532ac7d7 XL |
148 | if self.is_assign_to_bool(expr, expected) { |
149 | // Error reported in `check_assign` so avoid emitting error again. | |
150 | err.delay_as_bug(); | |
dfeec247 | 151 | return (expected, None); |
abe05a73 | 152 | } |
3b2f2976 | 153 | |
f035d41b | 154 | self.emit_coerce_suggestions(&mut err, expr, expr_ty, expected, expected_ty_expr); |
8faf50e0 | 155 | |
abe05a73 | 156 | (expected, Some(err)) |
32a655c1 SL |
157 | } |
158 | ||
dfeec247 XL |
159 | fn annotate_expected_due_to_let_ty( |
160 | &self, | |
161 | err: &mut DiagnosticBuilder<'_>, | |
162 | expr: &hir::Expr<'_>, | |
163 | ) { | |
60c5eb7d | 164 | let parent = self.tcx.hir().get_parent_node(expr.hir_id); |
dfeec247 XL |
165 | if let Some(hir::Node::Local(hir::Local { ty: Some(ty), init: Some(init), .. })) = |
166 | self.tcx.hir().find(parent) | |
167 | { | |
60c5eb7d XL |
168 | if init.hir_id == expr.hir_id { |
169 | // Point at `let` assignment type. | |
170 | err.span_label(ty.span, "expected due to this"); | |
171 | } | |
172 | } | |
173 | } | |
174 | ||
532ac7d7 | 175 | /// Returns whether the expected type is `bool` and the expression is `x = y`. |
dfeec247 | 176 | pub fn is_assign_to_bool(&self, expr: &hir::Expr<'_>, expected: Ty<'tcx>) -> bool { |
e74abb32 | 177 | if let hir::ExprKind::Assign(..) = expr.kind { |
532ac7d7 XL |
178 | return expected == self.tcx.types.bool; |
179 | } | |
180 | false | |
181 | } | |
182 | ||
183 | /// If the expected type is an enum (Issue #55250) with any variants whose | |
184 | /// sole field is of the found type, suggest such variants. (Issue #42764) | |
185 | fn suggest_compatible_variants( | |
186 | &self, | |
187 | err: &mut DiagnosticBuilder<'_>, | |
dfeec247 | 188 | expr: &hir::Expr<'_>, |
532ac7d7 XL |
189 | expected: Ty<'tcx>, |
190 | expr_ty: Ty<'tcx>, | |
191 | ) { | |
1b1a35ee | 192 | if let ty::Adt(expected_adt, substs) = expected.kind() { |
532ac7d7 XL |
193 | if !expected_adt.is_enum() { |
194 | return; | |
195 | } | |
196 | ||
dfeec247 XL |
197 | let mut compatible_variants = expected_adt |
198 | .variants | |
532ac7d7 XL |
199 | .iter() |
200 | .filter(|variant| variant.fields.len() == 1) | |
201 | .filter_map(|variant| { | |
202 | let sole_field = &variant.fields[0]; | |
203 | let sole_field_ty = sole_field.ty(self.tcx, substs); | |
204 | if self.can_coerce(expr_ty, sole_field_ty) { | |
136023e0 XL |
205 | let variant_path = |
206 | with_no_trimmed_paths(|| self.tcx.def_path_str(variant.def_id)); | |
532ac7d7 | 207 | // FIXME #56861: DRYer prelude filtering |
6a06907d XL |
208 | if let Some(path) = variant_path.strip_prefix("std::prelude::") { |
209 | if let Some((_, path)) = path.split_once("::") { | |
210 | return Some(path.to_string()); | |
211 | } | |
212 | } | |
213 | Some(variant_path) | |
532ac7d7 XL |
214 | } else { |
215 | None | |
216 | } | |
dfeec247 XL |
217 | }) |
218 | .peekable(); | |
532ac7d7 XL |
219 | |
220 | if compatible_variants.peek().is_some() { | |
ba9703b0 XL |
221 | if let Ok(expr_text) = self.tcx.sess.source_map().span_to_snippet(expr.span) { |
222 | let suggestions = compatible_variants.map(|v| format!("{}({})", v, expr_text)); | |
223 | let msg = "try using a variant of the expected enum"; | |
224 | err.span_suggestions( | |
225 | expr.span, | |
226 | msg, | |
227 | suggestions, | |
228 | Applicability::MaybeIncorrect, | |
229 | ); | |
230 | } | |
532ac7d7 XL |
231 | } |
232 | } | |
233 | } | |
234 | ||
dfeec247 XL |
235 | pub fn get_conversion_methods( |
236 | &self, | |
237 | span: Span, | |
238 | expected: Ty<'tcx>, | |
239 | checked_ty: Ty<'tcx>, | |
ba9703b0 | 240 | hir_id: hir::HirId, |
dfeec247 | 241 | ) -> Vec<AssocItem> { |
ba9703b0 XL |
242 | let mut methods = |
243 | self.probe_for_return_type(span, probe::Mode::MethodCall, expected, checked_ty, hir_id); | |
2c00a5a8 | 244 | methods.retain(|m| { |
ba9703b0 | 245 | self.has_only_self_parameter(m) |
dfeec247 XL |
246 | && self |
247 | .tcx | |
248 | .get_attrs(m.def_id) | |
249 | .iter() | |
f035d41b | 250 | // This special internal attribute is used to permit |
dfeec247 XL |
251 | // "identity-like" conversion methods to be suggested here. |
252 | // | |
253 | // FIXME (#46459 and #46460): ideally | |
254 | // `std::convert::Into::into` and `std::borrow:ToOwned` would | |
255 | // also be `#[rustc_conversion_suggestion]`, if not for | |
256 | // method-probing false-positives and -negatives (respectively). | |
257 | // | |
258 | // FIXME? Other potential candidate methods: `as_ref` and | |
259 | // `as_mut`? | |
3dfed10e | 260 | .any(|a| self.sess().check_name(a, sym::rustc_conversion_suggestion)) |
2c00a5a8 | 261 | }); |
32a655c1 | 262 | |
2c00a5a8 | 263 | methods |
32a655c1 SL |
264 | } |
265 | ||
ba9703b0 XL |
266 | /// This function checks whether the method is not static and does not accept other parameters than `self`. |
267 | fn has_only_self_parameter(&self, method: &AssocItem) -> bool { | |
48663c56 | 268 | match method.kind { |
ba9703b0 XL |
269 | ty::AssocKind::Fn => { |
270 | method.fn_has_self_parameter | |
271 | && self.tcx.fn_sig(method.def_id).inputs().skip_binder().len() == 1 | |
32a655c1 SL |
272 | } |
273 | _ => false, | |
a7813a04 XL |
274 | } |
275 | } | |
cc61c64b | 276 | |
94b46f34 XL |
277 | /// Identify some cases where `as_ref()` would be appropriate and suggest it. |
278 | /// | |
279 | /// Given the following code: | |
280 | /// ``` | |
281 | /// struct Foo; | |
282 | /// fn takes_ref(_: &Foo) {} | |
283 | /// let ref opt = Some(Foo); | |
284 | /// | |
e1599b0c | 285 | /// opt.map(|param| takes_ref(param)); |
94b46f34 | 286 | /// ``` |
e1599b0c | 287 | /// Suggest using `opt.as_ref().map(|param| takes_ref(param));` instead. |
94b46f34 XL |
288 | /// |
289 | /// It only checks for `Option` and `Result` and won't work with | |
290 | /// ``` | |
e1599b0c | 291 | /// opt.map(|param| { takes_ref(param) }); |
94b46f34 | 292 | /// ``` |
dfeec247 | 293 | fn can_use_as_ref(&self, expr: &hir::Expr<'_>) -> Option<(Span, &'static str, String)> { |
e74abb32 | 294 | let path = match expr.kind { |
416331ca | 295 | hir::ExprKind::Path(hir::QPath::Resolved(_, ref path)) => path, |
dfeec247 | 296 | _ => return None, |
416331ca XL |
297 | }; |
298 | ||
299 | let local_id = match path.res { | |
300 | hir::def::Res::Local(id) => id, | |
dfeec247 | 301 | _ => return None, |
416331ca XL |
302 | }; |
303 | ||
304 | let local_parent = self.tcx.hir().get_parent_node(local_id); | |
e1599b0c XL |
305 | let param_hir_id = match self.tcx.hir().find(local_parent) { |
306 | Some(Node::Param(hir::Param { hir_id, .. })) => hir_id, | |
dfeec247 | 307 | _ => return None, |
416331ca XL |
308 | }; |
309 | ||
e1599b0c XL |
310 | let param_parent = self.tcx.hir().get_parent_node(*param_hir_id); |
311 | let (expr_hir_id, closure_fn_decl) = match self.tcx.hir().find(param_parent) { | |
dfeec247 XL |
312 | Some(Node::Expr(hir::Expr { |
313 | hir_id, | |
314 | kind: hir::ExprKind::Closure(_, decl, ..), | |
315 | .. | |
316 | })) => (hir_id, decl), | |
317 | _ => return None, | |
416331ca XL |
318 | }; |
319 | ||
320 | let expr_parent = self.tcx.hir().get_parent_node(*expr_hir_id); | |
321 | let hir = self.tcx.hir().find(expr_parent); | |
322 | let closure_params_len = closure_fn_decl.inputs.len(); | |
323 | let (method_path, method_span, method_expr) = match (hir, closure_params_len) { | |
dfeec247 XL |
324 | ( |
325 | Some(Node::Expr(hir::Expr { | |
f035d41b | 326 | kind: hir::ExprKind::MethodCall(path, span, expr, _), |
dfeec247 XL |
327 | .. |
328 | })), | |
329 | 1, | |
330 | ) => (path, span, expr), | |
331 | _ => return None, | |
416331ca XL |
332 | }; |
333 | ||
3dfed10e | 334 | let self_ty = self.typeck_results.borrow().node_type(method_expr[0].hir_id); |
416331ca | 335 | let self_ty = format!("{:?}", self_ty); |
3dfed10e | 336 | let name = method_path.ident.name; |
dfeec247 XL |
337 | let is_as_ref_able = (self_ty.starts_with("&std::option::Option") |
338 | || self_ty.starts_with("&std::result::Result") | |
339 | || self_ty.starts_with("std::option::Option") | |
340 | || self_ty.starts_with("std::result::Result")) | |
3dfed10e | 341 | && (name == sym::map || name == sym::and_then); |
416331ca XL |
342 | match (is_as_ref_able, self.sess().source_map().span_to_snippet(*method_span)) { |
343 | (true, Ok(src)) => { | |
344 | let suggestion = format!("as_ref().{}", src); | |
345 | Some((*method_span, "consider using `as_ref` instead", suggestion)) | |
dfeec247 XL |
346 | } |
347 | _ => None, | |
94b46f34 | 348 | } |
94b46f34 XL |
349 | } |
350 | ||
dc9dc135 XL |
351 | crate fn is_hir_id_from_struct_pattern_shorthand_field( |
352 | &self, | |
353 | hir_id: hir::HirId, | |
354 | sp: Span, | |
355 | ) -> bool { | |
74b04a01 | 356 | let sm = self.sess().source_map(); |
dc9dc135 XL |
357 | let parent_id = self.tcx.hir().get_parent_node(hir_id); |
358 | if let Some(parent) = self.tcx.hir().find(parent_id) { | |
532ac7d7 | 359 | // Account for fields |
dfeec247 XL |
360 | if let Node::Expr(hir::Expr { kind: hir::ExprKind::Struct(_, fields, ..), .. }) = parent |
361 | { | |
74b04a01 | 362 | if let Ok(src) = sm.span_to_snippet(sp) { |
dfeec247 | 363 | for field in *fields { |
60c5eb7d | 364 | if field.ident.as_str() == src && field.is_shorthand { |
532ac7d7 XL |
365 | return true; |
366 | } | |
367 | } | |
368 | } | |
369 | } | |
370 | } | |
371 | false | |
372 | } | |
373 | ||
cdc7bbd5 XL |
374 | /// If the given `HirId` corresponds to a block with a trailing expression, return that expression |
375 | crate fn maybe_get_block_expr(&self, hir_id: hir::HirId) -> Option<&'tcx hir::Expr<'tcx>> { | |
376 | match self.tcx.hir().find(hir_id)? { | |
377 | Node::Expr(hir::Expr { kind: hir::ExprKind::Block(block, ..), .. }) => block.expr, | |
378 | _ => None, | |
379 | } | |
380 | } | |
381 | ||
382 | /// Returns whether the given expression is an `else if`. | |
383 | crate fn is_else_if_block(&self, expr: &hir::Expr<'_>) -> bool { | |
384 | if let hir::ExprKind::If(..) = expr.kind { | |
385 | let parent_id = self.tcx.hir().get_parent_node(expr.hir_id); | |
386 | if let Some(Node::Expr(hir::Expr { | |
387 | kind: hir::ExprKind::If(_, _, Some(else_expr)), | |
388 | .. | |
389 | })) = self.tcx.hir().find(parent_id) | |
390 | { | |
391 | return else_expr.hir_id == expr.hir_id; | |
392 | } | |
393 | } | |
394 | false | |
395 | } | |
396 | ||
cc61c64b XL |
397 | /// This function is used to determine potential "simple" improvements or users' errors and |
398 | /// provide them useful help. For example: | |
399 | /// | |
400 | /// ``` | |
401 | /// fn some_fn(s: &str) {} | |
402 | /// | |
403 | /// let x = "hey!".to_owned(); | |
404 | /// some_fn(x); // error | |
405 | /// ``` | |
406 | /// | |
407 | /// No need to find every potential function which could make a coercion to transform a | |
408 | /// `String` into a `&str` since a `&` would do the trick! | |
409 | /// | |
410 | /// In addition of this check, it also checks between references mutability state. If the | |
411 | /// expected is mutable but the provided isn't, maybe we could just say "Hey, try with | |
412 | /// `&mut`!". | |
dc9dc135 XL |
413 | pub fn check_ref( |
414 | &self, | |
dfeec247 | 415 | expr: &hir::Expr<'_>, |
dc9dc135 XL |
416 | checked_ty: Ty<'tcx>, |
417 | expected: Ty<'tcx>, | |
f9f354fc | 418 | ) -> Option<(Span, &'static str, String, Applicability)> { |
17df50a5 | 419 | let sess = self.sess(); |
532ac7d7 | 420 | let sp = expr.span; |
17df50a5 XL |
421 | |
422 | // If the span is from an external macro, there's no suggestion we can make. | |
423 | if in_external_macro(sess, sp) { | |
8faf50e0 XL |
424 | return None; |
425 | } | |
426 | ||
17df50a5 XL |
427 | let sm = sess.source_map(); |
428 | ||
fc512014 XL |
429 | let replace_prefix = |s: &str, old: &str, new: &str| { |
430 | s.strip_prefix(old).map(|stripped| new.to_string() + stripped) | |
431 | }; | |
432 | ||
dfeec247 XL |
433 | let is_struct_pat_shorthand_field = |
434 | self.is_hir_id_from_struct_pattern_shorthand_field(expr.hir_id, sp); | |
532ac7d7 | 435 | |
e74abb32 XL |
436 | // `ExprKind::DropTemps` is semantically irrelevant for these suggestions. |
437 | let expr = expr.peel_drop_temps(); | |
48663c56 | 438 | |
1b1a35ee XL |
439 | match (&expr.kind, expected.kind(), checked_ty.kind()) { |
440 | (_, &ty::Ref(_, exp, _), &ty::Ref(_, check, _)) => match (exp.kind(), check.kind()) { | |
ba9703b0 | 441 | (&ty::Str, &ty::Array(arr, _) | &ty::Slice(arr)) if arr == self.tcx.types.u8 => { |
e74abb32 | 442 | if let hir::ExprKind::Lit(_) = expr.kind { |
74b04a01 | 443 | if let Ok(src) = sm.span_to_snippet(sp) { |
fc512014 | 444 | if let Some(src) = replace_prefix(&src, "b\"", "\"") { |
dfeec247 XL |
445 | return Some(( |
446 | sp, | |
447 | "consider removing the leading `b`", | |
f9f354fc XL |
448 | src, |
449 | Applicability::MachineApplicable, | |
dfeec247 | 450 | )); |
8faf50e0 | 451 | } |
ea8adc8c XL |
452 | } |
453 | } | |
dfeec247 | 454 | } |
ba9703b0 | 455 | (&ty::Array(arr, _) | &ty::Slice(arr), &ty::Str) if arr == self.tcx.types.u8 => { |
e74abb32 | 456 | if let hir::ExprKind::Lit(_) = expr.kind { |
74b04a01 | 457 | if let Ok(src) = sm.span_to_snippet(sp) { |
fc512014 | 458 | if let Some(src) = replace_prefix(&src, "\"", "b\"") { |
dfeec247 XL |
459 | return Some(( |
460 | sp, | |
461 | "consider adding a leading `b`", | |
f9f354fc XL |
462 | src, |
463 | Applicability::MachineApplicable, | |
dfeec247 | 464 | )); |
8faf50e0 | 465 | } |
ea8adc8c XL |
466 | } |
467 | } | |
ea8adc8c | 468 | } |
94b46f34 | 469 | _ => {} |
ea8adc8c | 470 | }, |
48663c56 | 471 | (_, &ty::Ref(_, _, mutability), _) => { |
cc61c64b XL |
472 | // Check if it can work when put into a ref. For example: |
473 | // | |
474 | // ``` | |
475 | // fn bar(x: &mut i32) {} | |
476 | // | |
477 | // let x = 0u32; | |
478 | // bar(&x); // error, expected &mut | |
479 | // ``` | |
94b46f34 | 480 | let ref_ty = match mutability { |
dfeec247 | 481 | hir::Mutability::Mut => { |
532ac7d7 XL |
482 | self.tcx.mk_mut_ref(self.tcx.mk_region(ty::ReStatic), checked_ty) |
483 | } | |
dfeec247 | 484 | hir::Mutability::Not => { |
532ac7d7 XL |
485 | self.tcx.mk_imm_ref(self.tcx.mk_region(ty::ReStatic), checked_ty) |
486 | } | |
cc61c64b XL |
487 | }; |
488 | if self.can_coerce(ref_ty, expected) { | |
dc9dc135 | 489 | let mut sugg_sp = sp; |
f035d41b | 490 | if let hir::ExprKind::MethodCall(ref segment, sp, ref args, _) = expr.kind { |
3dfed10e | 491 | let clone_trait = self.tcx.require_lang_item(LangItem::Clone, Some(sp)); |
60c5eb7d | 492 | if let ([arg], Some(true), sym::clone) = ( |
dc9dc135 | 493 | &args[..], |
3dfed10e XL |
494 | self.typeck_results.borrow().type_dependent_def_id(expr.hir_id).map( |
495 | |did| { | |
496 | let ai = self.tcx.associated_item(did); | |
497 | ai.container == ty::TraitContainer(clone_trait) | |
498 | }, | |
499 | ), | |
60c5eb7d | 500 | segment.ident.name, |
dc9dc135 XL |
501 | ) { |
502 | // If this expression had a clone call when suggesting borrowing | |
60c5eb7d | 503 | // we want to suggest removing it because it'd now be unnecessary. |
dc9dc135 XL |
504 | sugg_sp = arg.span; |
505 | } | |
506 | } | |
74b04a01 | 507 | if let Ok(src) = sm.span_to_snippet(sugg_sp) { |
e74abb32 | 508 | let needs_parens = match expr.kind { |
0bf4aa26 | 509 | // parenthesize if needed (Issue #46756) |
dfeec247 | 510 | hir::ExprKind::Cast(_, _) | hir::ExprKind::Binary(_, _, _) => true, |
0bf4aa26 | 511 | // parenthesize borrows of range literals (Issue #54505) |
3dfed10e | 512 | _ if is_range_literal(expr) => true, |
0bf4aa26 XL |
513 | _ => false, |
514 | }; | |
dfeec247 | 515 | let sugg_expr = if needs_parens { format!("({})", src) } else { src }; |
0bf4aa26 | 516 | |
94b46f34 | 517 | if let Some(sugg) = self.can_use_as_ref(expr) { |
f9f354fc XL |
518 | return Some(( |
519 | sugg.0, | |
520 | sugg.1, | |
521 | sugg.2, | |
522 | Applicability::MachineApplicable, | |
523 | )); | |
94b46f34 | 524 | } |
532ac7d7 XL |
525 | let field_name = if is_struct_pat_shorthand_field { |
526 | format!("{}: ", sugg_expr) | |
527 | } else { | |
528 | String::new() | |
529 | }; | |
dc9dc135 | 530 | if let Some(hir::Node::Expr(hir::Expr { |
dfeec247 | 531 | kind: hir::ExprKind::Assign(left_expr, ..), |
dc9dc135 | 532 | .. |
dfeec247 XL |
533 | })) = self.tcx.hir().find(self.tcx.hir().get_parent_node(expr.hir_id)) |
534 | { | |
535 | if mutability == hir::Mutability::Mut { | |
dc9dc135 XL |
536 | // Found the following case: |
537 | // fn foo(opt: &mut Option<String>){ opt = None } | |
538 | // --- ^^^^ | |
539 | // | | | |
540 | // consider dereferencing here: `*opt` | | |
541 | // expected mutable reference, found enum `Option` | |
74b04a01 | 542 | if let Ok(src) = sm.span_to_snippet(left_expr.span) { |
dc9dc135 XL |
543 | return Some(( |
544 | left_expr.span, | |
545 | "consider dereferencing here to assign to the mutable \ | |
546 | borrowed piece of memory", | |
547 | format!("*{}", src), | |
f9f354fc | 548 | Applicability::MachineApplicable, |
dc9dc135 XL |
549 | )); |
550 | } | |
551 | } | |
552 | } | |
553 | ||
94b46f34 | 554 | return Some(match mutability { |
dfeec247 | 555 | hir::Mutability::Mut => ( |
532ac7d7 XL |
556 | sp, |
557 | "consider mutably borrowing here", | |
558 | format!("{}&mut {}", field_name, sugg_expr), | |
f9f354fc | 559 | Applicability::MachineApplicable, |
532ac7d7 | 560 | ), |
dfeec247 | 561 | hir::Mutability::Not => ( |
532ac7d7 XL |
562 | sp, |
563 | "consider borrowing here", | |
564 | format!("{}&{}", field_name, sugg_expr), | |
f9f354fc | 565 | Applicability::MachineApplicable, |
532ac7d7 | 566 | ), |
ff7c6d11 | 567 | }); |
cc61c64b XL |
568 | } |
569 | } | |
dfeec247 | 570 | } |
60c5eb7d XL |
571 | ( |
572 | hir::ExprKind::AddrOf(hir::BorrowKind::Ref, _, ref expr), | |
573 | _, | |
dfeec247 | 574 | &ty::Ref(_, checked, _), |
17df50a5 | 575 | ) if self.infcx.can_sub(self.param_env, checked, &expected).is_ok() => { |
ea8adc8c | 576 | // We have `&T`, check if what was expected was `T`. If so, |
48663c56 | 577 | // we may want to suggest removing a `&`. |
ba9703b0 | 578 | if sm.is_imported(expr.span) { |
17df50a5 XL |
579 | // Go through the spans from which this span was expanded, |
580 | // and find the one that's pointing inside `sp`. | |
581 | // | |
582 | // E.g. for `&format!("")`, where we want the span to the | |
583 | // `format!()` invocation instead of its expansion. | |
584 | if let Some(call_span) = | |
585 | iter::successors(Some(expr.span), |s| s.parent()).find(|&s| sp.contains(s)) | |
586 | { | |
587 | if let Ok(code) = sm.span_to_snippet(call_span) { | |
48663c56 XL |
588 | return Some(( |
589 | sp, | |
590 | "consider removing the borrow", | |
17df50a5 | 591 | code, |
f9f354fc | 592 | Applicability::MachineApplicable, |
48663c56 | 593 | )); |
2c00a5a8 | 594 | } |
ea8adc8c | 595 | } |
48663c56 | 596 | return None; |
ea8adc8c | 597 | } |
17df50a5 XL |
598 | if sp.contains(expr.span) { |
599 | if let Ok(code) = sm.span_to_snippet(expr.span) { | |
600 | return Some(( | |
601 | sp, | |
602 | "consider removing the borrow", | |
603 | code, | |
604 | Applicability::MachineApplicable, | |
605 | )); | |
606 | } | |
f9f354fc XL |
607 | } |
608 | } | |
609 | ( | |
610 | _, | |
611 | &ty::RawPtr(TypeAndMut { ty: ty_b, mutbl: mutbl_b }), | |
612 | &ty::Ref(_, ty_a, mutbl_a), | |
613 | ) => { | |
614 | if let Some(steps) = self.deref_steps(ty_a, ty_b) { | |
615 | // Only suggest valid if dereferencing needed. | |
616 | if steps > 0 { | |
617 | // The pointer type implements `Copy` trait so the suggestion is always valid. | |
618 | if let Ok(src) = sm.span_to_snippet(sp) { | |
619 | let derefs = &"*".repeat(steps); | |
620 | if let Some((src, applicability)) = match mutbl_b { | |
621 | hir::Mutability::Mut => { | |
622 | let new_prefix = "&mut ".to_owned() + derefs; | |
623 | match mutbl_a { | |
624 | hir::Mutability::Mut => { | |
fc512014 XL |
625 | replace_prefix(&src, "&mut ", &new_prefix) |
626 | .map(|s| (s, Applicability::MachineApplicable)) | |
f9f354fc XL |
627 | } |
628 | hir::Mutability::Not => { | |
fc512014 XL |
629 | replace_prefix(&src, "&", &new_prefix) |
630 | .map(|s| (s, Applicability::Unspecified)) | |
f9f354fc XL |
631 | } |
632 | } | |
633 | } | |
634 | hir::Mutability::Not => { | |
635 | let new_prefix = "&".to_owned() + derefs; | |
636 | match mutbl_a { | |
637 | hir::Mutability::Mut => { | |
fc512014 XL |
638 | replace_prefix(&src, "&mut ", &new_prefix) |
639 | .map(|s| (s, Applicability::MachineApplicable)) | |
f9f354fc XL |
640 | } |
641 | hir::Mutability::Not => { | |
fc512014 XL |
642 | replace_prefix(&src, "&", &new_prefix) |
643 | .map(|s| (s, Applicability::MachineApplicable)) | |
f9f354fc XL |
644 | } |
645 | } | |
646 | } | |
647 | } { | |
648 | return Some((sp, "consider dereferencing", src, applicability)); | |
649 | } | |
650 | } | |
651 | } | |
9fa01778 | 652 | } |
dfeec247 | 653 | } |
17df50a5 | 654 | _ if sp == expr.span => { |
f9f354fc | 655 | if let Some(steps) = self.deref_steps(checked_ty, expected) { |
6a06907d XL |
656 | let expr = expr.peel_blocks(); |
657 | ||
f9f354fc | 658 | if steps == 1 { |
6a06907d XL |
659 | if let hir::ExprKind::AddrOf(_, mutbl, inner) = expr.kind { |
660 | // If the expression has `&`, removing it would fix the error | |
661 | let prefix_span = expr.span.with_hi(inner.span.lo()); | |
662 | let message = match mutbl { | |
663 | hir::Mutability::Not => "consider removing the `&`", | |
664 | hir::Mutability::Mut => "consider removing the `&mut`", | |
665 | }; | |
666 | let suggestion = String::new(); | |
667 | return Some(( | |
668 | prefix_span, | |
669 | message, | |
670 | suggestion, | |
671 | Applicability::MachineApplicable, | |
672 | )); | |
673 | } else if self.infcx.type_is_copy_modulo_regions( | |
674 | self.param_env, | |
675 | expected, | |
676 | sp, | |
677 | ) { | |
678 | // For this suggestion to make sense, the type would need to be `Copy`. | |
679 | if let Ok(code) = sm.span_to_snippet(expr.span) { | |
f9f354fc XL |
680 | let message = if checked_ty.is_region_ptr() { |
681 | "consider dereferencing the borrow" | |
682 | } else { | |
683 | "consider dereferencing the type" | |
684 | }; | |
685 | let suggestion = if is_struct_pat_shorthand_field { | |
686 | format!("{}: *{}", code, code) | |
cdc7bbd5 XL |
687 | } else if self.is_else_if_block(expr) { |
688 | // Don't suggest nonsense like `else *if` | |
689 | return None; | |
690 | } else if let Some(expr) = self.maybe_get_block_expr(expr.hir_id) { | |
691 | format!("*{}", sm.span_to_snippet(expr.span).unwrap_or(code)) | |
f9f354fc XL |
692 | } else { |
693 | format!("*{}", code) | |
694 | }; | |
695 | return Some(( | |
6a06907d | 696 | expr.span, |
f9f354fc XL |
697 | message, |
698 | suggestion, | |
699 | Applicability::MachineApplicable, | |
700 | )); | |
701 | } | |
702 | } | |
0bf4aa26 XL |
703 | } |
704 | } | |
705 | } | |
0bf4aa26 XL |
706 | _ => {} |
707 | } | |
48663c56 | 708 | None |
0bf4aa26 XL |
709 | } |
710 | ||
9fa01778 XL |
711 | pub fn check_for_cast( |
712 | &self, | |
60c5eb7d | 713 | err: &mut DiagnosticBuilder<'_>, |
dfeec247 | 714 | expr: &hir::Expr<'_>, |
9fa01778 XL |
715 | checked_ty: Ty<'tcx>, |
716 | expected_ty: Ty<'tcx>, | |
f035d41b | 717 | expected_ty_expr: Option<&'tcx hir::Expr<'tcx>>, |
9fa01778 | 718 | ) -> bool { |
ba9703b0 | 719 | if self.tcx.sess.source_map().is_imported(expr.span) { |
e1599b0c XL |
720 | // Ignore if span is from within a macro. |
721 | return false; | |
722 | } | |
2c00a5a8 | 723 | |
f035d41b XL |
724 | let src = if let Ok(src) = self.tcx.sess.source_map().span_to_snippet(expr.span) { |
725 | src | |
726 | } else { | |
727 | return false; | |
728 | }; | |
729 | ||
2c00a5a8 XL |
730 | // If casting this expression to a given numeric type would be appropriate in case of a type |
731 | // mismatch. | |
732 | // | |
733 | // We want to minimize the amount of casting operations that are suggested, as it can be a | |
734 | // lossy operation with potentially bad side effects, so we only suggest when encountering | |
735 | // an expression that indicates that the original type couldn't be directly changed. | |
736 | // | |
737 | // For now, don't suggest casting with `as`. | |
738 | let can_cast = false; | |
739 | ||
f9f354fc XL |
740 | let prefix = if let Some(hir::Node::Expr(hir::Expr { |
741 | kind: hir::ExprKind::Struct(_, fields, _), | |
742 | .. | |
dfeec247 XL |
743 | })) = self.tcx.hir().find(self.tcx.hir().get_parent_node(expr.hir_id)) |
744 | { | |
9fa01778 | 745 | // `expr` is a literal field for a struct, only suggest if appropriate |
f9f354fc XL |
746 | match (*fields) |
747 | .iter() | |
748 | .find(|field| field.expr.hir_id == expr.hir_id && field.is_shorthand) | |
749 | { | |
750 | // This is a field literal | |
751 | Some(field) => format!("{}: ", field.ident), | |
9fa01778 | 752 | // Likely a field was meant, but this field wasn't found. Do not suggest anything. |
f9f354fc | 753 | None => return false, |
9fa01778 | 754 | } |
f9f354fc XL |
755 | } else { |
756 | String::new() | |
757 | }; | |
f035d41b | 758 | |
e74abb32 | 759 | if let hir::ExprKind::Call(path, args) = &expr.kind { |
dfeec247 XL |
760 | if let (hir::ExprKind::Path(hir::QPath::TypeRelative(base_ty, path_segment)), 1) = |
761 | (&path.kind, args.len()) | |
762 | { | |
e1599b0c | 763 | // `expr` is a conversion like `u32::from(val)`, do not suggest anything (#63697). |
dfeec247 XL |
764 | if let (hir::TyKind::Path(hir::QPath::Resolved(None, base_ty_path)), sym::from) = |
765 | (&base_ty.kind, path_segment.ident.name) | |
766 | { | |
e1599b0c XL |
767 | if let Some(ident) = &base_ty_path.segments.iter().map(|s| s.ident).next() { |
768 | match ident.name { | |
dfeec247 XL |
769 | sym::i128 |
770 | | sym::i64 | |
771 | | sym::i32 | |
772 | | sym::i16 | |
773 | | sym::i8 | |
774 | | sym::u128 | |
775 | | sym::u64 | |
776 | | sym::u32 | |
777 | | sym::u16 | |
778 | | sym::u8 | |
779 | | sym::isize | |
780 | | sym::usize | |
781 | if base_ty_path.segments.len() == 1 => | |
782 | { | |
e1599b0c XL |
783 | return false; |
784 | } | |
785 | _ => {} | |
786 | } | |
787 | } | |
788 | } | |
789 | } | |
790 | } | |
9fa01778 | 791 | |
29967ef6 XL |
792 | let msg = format!( |
793 | "you can convert {} `{}` to {} `{}`", | |
794 | checked_ty.kind().article(), | |
795 | checked_ty, | |
796 | expected_ty.kind().article(), | |
797 | expected_ty, | |
798 | ); | |
799 | let cast_msg = format!( | |
800 | "you can cast {} `{}` to {} `{}`", | |
801 | checked_ty.kind().article(), | |
802 | checked_ty, | |
803 | expected_ty.kind().article(), | |
804 | expected_ty, | |
805 | ); | |
48663c56 XL |
806 | let lit_msg = format!( |
807 | "change the type of the numeric literal from `{}` to `{}`", | |
dfeec247 | 808 | checked_ty, expected_ty, |
48663c56 XL |
809 | ); |
810 | ||
f035d41b XL |
811 | let with_opt_paren: fn(&dyn fmt::Display) -> String = |
812 | if expr.precedence().order() < PREC_POSTFIX { | |
813 | |s| format!("({})", s) | |
814 | } else { | |
815 | |s| s.to_string() | |
816 | }; | |
817 | ||
818 | let cast_suggestion = format!("{}{} as {}", prefix, with_opt_paren(&src), expected_ty); | |
819 | let into_suggestion = format!("{}{}.into()", prefix, with_opt_paren(&src)); | |
820 | let suffix_suggestion = with_opt_paren(&format_args!( | |
821 | "{}{}", | |
822 | if matches!( | |
1b1a35ee | 823 | (&expected_ty.kind(), &checked_ty.kind()), |
f035d41b XL |
824 | (ty::Int(_) | ty::Uint(_), ty::Float(_)) |
825 | ) { | |
826 | // Remove fractional part from literal, for example `42.0f32` into `42` | |
827 | let src = src.trim_end_matches(&checked_ty.to_string()); | |
828 | src.split('.').next().unwrap() | |
829 | } else { | |
830 | src.trim_end_matches(&checked_ty.to_string()) | |
831 | }, | |
832 | expected_ty, | |
833 | )); | |
834 | let literal_is_ty_suffixed = |expr: &hir::Expr<'_>| { | |
835 | if let hir::ExprKind::Lit(lit) = &expr.kind { lit.node.is_suffixed() } else { false } | |
836 | }; | |
837 | let is_negative_int = | |
6a06907d | 838 | |expr: &hir::Expr<'_>| matches!(expr.kind, hir::ExprKind::Unary(hir::UnOp::Neg, ..)); |
1b1a35ee | 839 | let is_uint = |ty: Ty<'_>| matches!(ty.kind(), ty::Uint(..)); |
f035d41b XL |
840 | |
841 | let in_const_context = self.tcx.hir().is_inside_const_context(expr.hir_id); | |
842 | ||
843 | let suggest_fallible_into_or_lhs_from = | |
844 | |err: &mut DiagnosticBuilder<'_>, exp_to_found_is_fallible: bool| { | |
845 | // If we know the expression the expected type is derived from, we might be able | |
846 | // to suggest a widening conversion rather than a narrowing one (which may | |
847 | // panic). For example, given x: u8 and y: u32, if we know the span of "x", | |
848 | // x > y | |
849 | // can be given the suggestion "u32::from(x) > y" rather than | |
850 | // "x > y.try_into().unwrap()". | |
851 | let lhs_expr_and_src = expected_ty_expr.and_then(|expr| { | |
fc512014 XL |
852 | self.tcx |
853 | .sess | |
854 | .source_map() | |
855 | .span_to_snippet(expr.span) | |
856 | .ok() | |
857 | .map(|src| (expr, src)) | |
f035d41b XL |
858 | }); |
859 | let (span, msg, suggestion) = if let (Some((lhs_expr, lhs_src)), false) = | |
860 | (lhs_expr_and_src, exp_to_found_is_fallible) | |
dfeec247 | 861 | { |
f035d41b XL |
862 | let msg = format!( |
863 | "you can convert `{}` from `{}` to `{}`, matching the type of `{}`", | |
864 | lhs_src, expected_ty, checked_ty, src | |
865 | ); | |
866 | let suggestion = format!("{}::from({})", checked_ty, lhs_src); | |
867 | (lhs_expr.span, msg, suggestion) | |
48663c56 | 868 | } else { |
29967ef6 | 869 | let msg = format!("{} and panic if the converted value doesn't fit", msg); |
f035d41b XL |
870 | let suggestion = |
871 | format!("{}{}.try_into().unwrap()", prefix, with_opt_paren(&src)); | |
872 | (expr.span, msg, suggestion) | |
873 | }; | |
874 | err.span_suggestion(span, &msg, suggestion, Applicability::MachineApplicable); | |
875 | }; | |
876 | ||
877 | let suggest_to_change_suffix_or_into = | |
878 | |err: &mut DiagnosticBuilder<'_>, | |
879 | found_to_exp_is_fallible: bool, | |
880 | exp_to_found_is_fallible: bool| { | |
5869c6ff XL |
881 | let exp_is_lhs = |
882 | expected_ty_expr.map(|e| self.tcx.hir().is_lhs(e.hir_id)).unwrap_or(false); | |
883 | ||
884 | if exp_is_lhs { | |
885 | return; | |
886 | } | |
887 | ||
f035d41b XL |
888 | let always_fallible = found_to_exp_is_fallible |
889 | && (exp_to_found_is_fallible || expected_ty_expr.is_none()); | |
890 | let msg = if literal_is_ty_suffixed(expr) { | |
891 | &lit_msg | |
892 | } else if always_fallible && (is_negative_int(expr) && is_uint(expected_ty)) { | |
893 | // We now know that converting either the lhs or rhs is fallible. Before we | |
894 | // suggest a fallible conversion, check if the value can never fit in the | |
895 | // expected type. | |
896 | let msg = format!("`{}` cannot fit into type `{}`", src, expected_ty); | |
897 | err.note(&msg); | |
898 | return; | |
899 | } else if in_const_context { | |
900 | // Do not recommend `into` or `try_into` in const contexts. | |
901 | return; | |
902 | } else if found_to_exp_is_fallible { | |
903 | return suggest_fallible_into_or_lhs_from(err, exp_to_found_is_fallible); | |
0bf4aa26 | 904 | } else { |
f035d41b XL |
905 | &msg |
906 | }; | |
907 | let suggestion = if literal_is_ty_suffixed(expr) { | |
908 | suffix_suggestion.clone() | |
909 | } else { | |
910 | into_suggestion.clone() | |
911 | }; | |
912 | err.span_suggestion(expr.span, msg, suggestion, Applicability::MachineApplicable); | |
0bf4aa26 XL |
913 | }; |
914 | ||
1b1a35ee | 915 | match (&expected_ty.kind(), &checked_ty.kind()) { |
f035d41b XL |
916 | (&ty::Int(ref exp), &ty::Int(ref found)) => { |
917 | let (f2e_is_fallible, e2f_is_fallible) = match (exp.bit_width(), found.bit_width()) | |
918 | { | |
919 | (Some(exp), Some(found)) if exp < found => (true, false), | |
920 | (Some(exp), Some(found)) if exp > found => (false, true), | |
921 | (None, Some(8 | 16)) => (false, true), | |
922 | (Some(8 | 16), None) => (true, false), | |
923 | (None, _) | (_, None) => (true, true), | |
924 | _ => (false, false), | |
925 | }; | |
926 | suggest_to_change_suffix_or_into(err, f2e_is_fallible, e2f_is_fallible); | |
927 | true | |
928 | } | |
929 | (&ty::Uint(ref exp), &ty::Uint(ref found)) => { | |
930 | let (f2e_is_fallible, e2f_is_fallible) = match (exp.bit_width(), found.bit_width()) | |
931 | { | |
932 | (Some(exp), Some(found)) if exp < found => (true, false), | |
933 | (Some(exp), Some(found)) if exp > found => (false, true), | |
934 | (None, Some(8 | 16)) => (false, true), | |
935 | (Some(8 | 16), None) => (true, false), | |
936 | (None, _) | (_, None) => (true, true), | |
937 | _ => (false, false), | |
938 | }; | |
939 | suggest_to_change_suffix_or_into(err, f2e_is_fallible, e2f_is_fallible); | |
940 | true | |
941 | } | |
942 | (&ty::Int(exp), &ty::Uint(found)) => { | |
943 | let (f2e_is_fallible, e2f_is_fallible) = match (exp.bit_width(), found.bit_width()) | |
944 | { | |
945 | (Some(exp), Some(found)) if found < exp => (false, true), | |
946 | (None, Some(8)) => (false, true), | |
947 | _ => (true, true), | |
948 | }; | |
949 | suggest_to_change_suffix_or_into(err, f2e_is_fallible, e2f_is_fallible); | |
950 | true | |
951 | } | |
952 | (&ty::Uint(exp), &ty::Int(found)) => { | |
953 | let (f2e_is_fallible, e2f_is_fallible) = match (exp.bit_width(), found.bit_width()) | |
954 | { | |
955 | (Some(exp), Some(found)) if found > exp => (true, false), | |
956 | (Some(8), None) => (true, false), | |
957 | _ => (true, true), | |
958 | }; | |
959 | suggest_to_change_suffix_or_into(err, f2e_is_fallible, e2f_is_fallible); | |
960 | true | |
961 | } | |
962 | (&ty::Float(ref exp), &ty::Float(ref found)) => { | |
963 | if found.bit_width() < exp.bit_width() { | |
964 | suggest_to_change_suffix_or_into(err, false, true); | |
965 | } else if literal_is_ty_suffixed(expr) { | |
dfeec247 XL |
966 | err.span_suggestion( |
967 | expr.span, | |
f035d41b XL |
968 | &lit_msg, |
969 | suffix_suggestion, | |
dfeec247 XL |
970 | Applicability::MachineApplicable, |
971 | ); | |
f035d41b XL |
972 | } else if can_cast { |
973 | // Missing try_into implementation for `f64` to `f32` | |
974 | err.span_suggestion( | |
975 | expr.span, | |
976 | &format!("{}, producing the closest possible value", cast_msg), | |
977 | cast_suggestion, | |
978 | Applicability::MaybeIncorrect, // lossy conversion | |
979 | ); | |
2c00a5a8 | 980 | } |
f035d41b XL |
981 | true |
982 | } | |
983 | (&ty::Uint(_) | &ty::Int(_), &ty::Float(_)) => { | |
984 | if literal_is_ty_suffixed(expr) { | |
985 | err.span_suggestion( | |
986 | expr.span, | |
987 | &lit_msg, | |
988 | suffix_suggestion, | |
989 | Applicability::MachineApplicable, | |
990 | ); | |
991 | } else if can_cast { | |
992 | // Missing try_into implementation for `{float}` to `{integer}` | |
993 | err.span_suggestion( | |
994 | expr.span, | |
995 | &format!("{}, rounding the float towards zero", msg), | |
996 | cast_suggestion, | |
997 | Applicability::MaybeIncorrect, // lossy conversion | |
998 | ); | |
2c00a5a8 | 999 | } |
f035d41b XL |
1000 | true |
1001 | } | |
1002 | (&ty::Float(ref exp), &ty::Uint(ref found)) => { | |
1003 | // if `found` is `None` (meaning found is `usize`), don't suggest `.into()` | |
1004 | if exp.bit_width() > found.bit_width().unwrap_or(256) { | |
1005 | err.span_suggestion( | |
1006 | expr.span, | |
1007 | &format!( | |
1008 | "{}, producing the floating point representation of the integer", | |
1009 | msg, | |
1010 | ), | |
1011 | into_suggestion, | |
1012 | Applicability::MachineApplicable, | |
1013 | ); | |
1014 | } else if literal_is_ty_suffixed(expr) { | |
1015 | err.span_suggestion( | |
1016 | expr.span, | |
1017 | &lit_msg, | |
1018 | suffix_suggestion, | |
1019 | Applicability::MachineApplicable, | |
1020 | ); | |
1021 | } else { | |
1022 | // Missing try_into implementation for `{integer}` to `{float}` | |
1023 | err.span_suggestion( | |
1024 | expr.span, | |
1025 | &format!( | |
1026 | "{}, producing the floating point representation of the integer, | |
48663c56 | 1027 | rounded if necessary", |
f035d41b XL |
1028 | cast_msg, |
1029 | ), | |
1030 | cast_suggestion, | |
1031 | Applicability::MaybeIncorrect, // lossy conversion | |
1032 | ); | |
2c00a5a8 | 1033 | } |
f035d41b XL |
1034 | true |
1035 | } | |
1036 | (&ty::Float(ref exp), &ty::Int(ref found)) => { | |
1037 | // if `found` is `None` (meaning found is `isize`), don't suggest `.into()` | |
1038 | if exp.bit_width() > found.bit_width().unwrap_or(256) { | |
1039 | err.span_suggestion( | |
1040 | expr.span, | |
1041 | &format!( | |
1042 | "{}, producing the floating point representation of the integer", | |
1043 | &msg, | |
1044 | ), | |
1045 | into_suggestion, | |
1046 | Applicability::MachineApplicable, | |
1047 | ); | |
1048 | } else if literal_is_ty_suffixed(expr) { | |
1049 | err.span_suggestion( | |
1050 | expr.span, | |
1051 | &lit_msg, | |
1052 | suffix_suggestion, | |
1053 | Applicability::MachineApplicable, | |
1054 | ); | |
1055 | } else { | |
1056 | // Missing try_into implementation for `{integer}` to `{float}` | |
1057 | err.span_suggestion( | |
1058 | expr.span, | |
1059 | &format!( | |
1060 | "{}, producing the floating point representation of the integer, \ | |
1061 | rounded if necessary", | |
1062 | &msg, | |
1063 | ), | |
1064 | cast_suggestion, | |
1065 | Applicability::MaybeIncorrect, // lossy conversion | |
1066 | ); | |
2c00a5a8 | 1067 | } |
f035d41b | 1068 | true |
2c00a5a8 | 1069 | } |
f035d41b | 1070 | _ => false, |
2c00a5a8 XL |
1071 | } |
1072 | } | |
cdc7bbd5 XL |
1073 | |
1074 | // Report the type inferred by the return statement. | |
1075 | fn report_closure_infered_return_type( | |
1076 | &self, | |
1077 | err: &mut DiagnosticBuilder<'_>, | |
1078 | expected: Ty<'tcx>, | |
1079 | ) { | |
1080 | if let Some(sp) = self.ret_coercion_span.get() { | |
1081 | // If the closure has an explicit return type annotation, | |
1082 | // then a type error may occur at the first return expression we | |
1083 | // see in the closure (if it conflicts with the declared | |
1084 | // return type). Skip adding a note in this case, since it | |
1085 | // would be incorrect. | |
1086 | if !err.span.primary_spans().iter().any(|&span| span == sp) { | |
1087 | let hir = self.tcx.hir(); | |
1088 | let body_owner = hir.body_owned_by(hir.enclosing_body_owner(self.body_id)); | |
1089 | if self.tcx.is_closure(hir.body_owner_def_id(body_owner).to_def_id()) { | |
1090 | err.span_note( | |
1091 | sp, | |
1092 | &format!( | |
1093 | "return type inferred to be `{}` here", | |
1094 | self.resolve_vars_if_possible(expected) | |
1095 | ), | |
1096 | ); | |
1097 | } | |
1098 | } | |
1099 | } | |
1100 | } | |
1a4d82fc | 1101 | } |