| use crate::check::FnCtxt; |
| use rustc_infer::infer::InferOk; |
| use rustc_middle::middle::stability::EvalResult; |
| use rustc_trait_selection::infer::InferCtxtExt as _; |
| use rustc_trait_selection::traits::ObligationCause; |
| |
| use rustc_ast::util::parser::PREC_POSTFIX; |
| use rustc_errors::{Applicability, Diagnostic, DiagnosticBuilder, ErrorGuaranteed}; |
| use rustc_hir as hir; |
| use rustc_hir::lang_items::LangItem; |
| use rustc_hir::{is_range_literal, Node}; |
| use rustc_middle::lint::in_external_macro; |
| use rustc_middle::ty::adjustment::AllowTwoPhase; |
| use rustc_middle::ty::error::{ExpectedFound, TypeError}; |
| use rustc_middle::ty::print::with_no_trimmed_paths; |
| use rustc_middle::ty::{self, Article, AssocItem, Ty, TypeAndMut}; |
| use rustc_span::symbol::{sym, Symbol}; |
| use rustc_span::{BytePos, Span}; |
| |
| use super::method::probe; |
| |
| use std::iter; |
| |
| impl<'a, 'tcx> FnCtxt<'a, 'tcx> { |
| pub fn emit_coerce_suggestions( |
| &self, |
| err: &mut Diagnostic, |
| expr: &hir::Expr<'tcx>, |
| expr_ty: Ty<'tcx>, |
| expected: Ty<'tcx>, |
| expected_ty_expr: Option<&'tcx hir::Expr<'tcx>>, |
| error: Option<TypeError<'tcx>>, |
| ) { |
| self.annotate_expected_due_to_let_ty(err, expr, error); |
| self.suggest_deref_ref_or_into(err, expr, expected, expr_ty, expected_ty_expr); |
| self.suggest_compatible_variants(err, expr, expected, expr_ty); |
| self.suggest_non_zero_new_unwrap(err, expr, expected, expr_ty); |
| if self.suggest_calling_boxed_future_when_appropriate(err, expr, expected, expr_ty) { |
| return; |
| } |
| self.suggest_no_capture_closure(err, expected, expr_ty); |
| self.suggest_boxing_when_appropriate(err, expr, expected, expr_ty); |
| self.suggest_missing_parentheses(err, expr); |
| self.suggest_block_to_brackets_peeling_refs(err, expr, expr_ty, expected); |
| self.suggest_copied_or_cloned(err, expr, expr_ty, expected); |
| self.note_type_is_not_clone(err, expected, expr_ty, expr); |
| self.note_need_for_fn_pointer(err, expected, expr_ty); |
| self.note_internal_mutation_in_method(err, expr, expected, expr_ty); |
| } |
| |
| // Requires that the two types unify, and prints an error message if |
| // they don't. |
| pub fn demand_suptype(&self, sp: Span, expected: Ty<'tcx>, actual: Ty<'tcx>) { |
| if let Some(mut e) = self.demand_suptype_diag(sp, expected, actual) { |
| e.emit(); |
| } |
| } |
| |
| pub fn demand_suptype_diag( |
| &self, |
| sp: Span, |
| expected: Ty<'tcx>, |
| actual: Ty<'tcx>, |
| ) -> Option<DiagnosticBuilder<'tcx, ErrorGuaranteed>> { |
| self.demand_suptype_with_origin(&self.misc(sp), expected, actual) |
| } |
| |
| #[instrument(skip(self), level = "debug")] |
| pub fn demand_suptype_with_origin( |
| &self, |
| cause: &ObligationCause<'tcx>, |
| expected: Ty<'tcx>, |
| actual: Ty<'tcx>, |
| ) -> Option<DiagnosticBuilder<'tcx, ErrorGuaranteed>> { |
| match self.at(cause, self.param_env).sup(expected, actual) { |
| Ok(InferOk { obligations, value: () }) => { |
| self.register_predicates(obligations); |
| None |
| } |
| Err(e) => Some(self.report_mismatched_types(&cause, expected, actual, e)), |
| } |
| } |
| |
| pub fn demand_eqtype(&self, sp: Span, expected: Ty<'tcx>, actual: Ty<'tcx>) { |
| if let Some(mut err) = self.demand_eqtype_diag(sp, expected, actual) { |
| err.emit(); |
| } |
| } |
| |
| pub fn demand_eqtype_diag( |
| &self, |
| sp: Span, |
| expected: Ty<'tcx>, |
| actual: Ty<'tcx>, |
| ) -> Option<DiagnosticBuilder<'tcx, ErrorGuaranteed>> { |
| self.demand_eqtype_with_origin(&self.misc(sp), expected, actual) |
| } |
| |
| pub fn demand_eqtype_with_origin( |
| &self, |
| cause: &ObligationCause<'tcx>, |
| expected: Ty<'tcx>, |
| actual: Ty<'tcx>, |
| ) -> Option<DiagnosticBuilder<'tcx, ErrorGuaranteed>> { |
| match self.at(cause, self.param_env).eq(expected, actual) { |
| Ok(InferOk { obligations, value: () }) => { |
| self.register_predicates(obligations); |
| None |
| } |
| Err(e) => Some(self.report_mismatched_types(cause, expected, actual, e)), |
| } |
| } |
| |
| pub fn demand_coerce( |
| &self, |
| expr: &hir::Expr<'tcx>, |
| checked_ty: Ty<'tcx>, |
| expected: Ty<'tcx>, |
| expected_ty_expr: Option<&'tcx hir::Expr<'tcx>>, |
| allow_two_phase: AllowTwoPhase, |
| ) -> Ty<'tcx> { |
| let (ty, err) = |
| self.demand_coerce_diag(expr, checked_ty, expected, expected_ty_expr, allow_two_phase); |
| if let Some(mut err) = err { |
| err.emit(); |
| } |
| ty |
| } |
| |
| /// Checks that the type of `expr` can be coerced to `expected`. |
| /// |
| /// N.B., this code relies on `self.diverges` to be accurate. In particular, assignments to `!` |
| /// will be permitted if the diverges flag is currently "always". |
| #[instrument(level = "debug", skip(self, expr, expected_ty_expr, allow_two_phase))] |
| pub fn demand_coerce_diag( |
| &self, |
| expr: &hir::Expr<'tcx>, |
| checked_ty: Ty<'tcx>, |
| expected: Ty<'tcx>, |
| expected_ty_expr: Option<&'tcx hir::Expr<'tcx>>, |
| allow_two_phase: AllowTwoPhase, |
| ) -> (Ty<'tcx>, Option<DiagnosticBuilder<'tcx, ErrorGuaranteed>>) { |
| let expected = self.resolve_vars_with_obligations(expected); |
| |
| let e = match self.try_coerce(expr, checked_ty, expected, allow_two_phase, None) { |
| Ok(ty) => return (ty, None), |
| Err(e) => e, |
| }; |
| |
| self.set_tainted_by_errors(); |
| let expr = expr.peel_drop_temps(); |
| let cause = self.misc(expr.span); |
| let expr_ty = self.resolve_vars_with_obligations(checked_ty); |
| let mut err = self.report_mismatched_types(&cause, expected, expr_ty, e.clone()); |
| |
| let is_insufficiently_polymorphic = |
| matches!(e, TypeError::RegionsInsufficientlyPolymorphic(..)); |
| |
| // FIXME(#73154): For now, we do leak check when coercing function |
| // pointers in typeck, instead of only during borrowck. This can lead |
| // to these `RegionsInsufficientlyPolymorphic` errors that aren't helpful. |
| if !is_insufficiently_polymorphic { |
| self.emit_coerce_suggestions( |
| &mut err, |
| expr, |
| expr_ty, |
| expected, |
| expected_ty_expr, |
| Some(e), |
| ); |
| } |
| |
| (expected, Some(err)) |
| } |
| |
| fn annotate_expected_due_to_let_ty( |
| &self, |
| err: &mut Diagnostic, |
| expr: &hir::Expr<'_>, |
| error: Option<TypeError<'_>>, |
| ) { |
| let parent = self.tcx.hir().get_parent_node(expr.hir_id); |
| match (self.tcx.hir().find(parent), error) { |
| (Some(hir::Node::Local(hir::Local { ty: Some(ty), init: Some(init), .. })), _) |
| if init.hir_id == expr.hir_id => |
| { |
| // Point at `let` assignment type. |
| err.span_label(ty.span, "expected due to this"); |
| } |
| ( |
| Some(hir::Node::Expr(hir::Expr { |
| kind: hir::ExprKind::Assign(lhs, rhs, _), .. |
| })), |
| Some(TypeError::Sorts(ExpectedFound { expected, .. })), |
| ) if rhs.hir_id == expr.hir_id && !expected.is_closure() => { |
| // We ignore closures explicitly because we already point at them elsewhere. |
| // Point at the assigned-to binding. |
| let mut primary_span = lhs.span; |
| let mut secondary_span = lhs.span; |
| let mut post_message = ""; |
| match lhs.kind { |
| hir::ExprKind::Path(hir::QPath::Resolved( |
| None, |
| hir::Path { |
| res: |
| hir::def::Res::Def( |
| hir::def::DefKind::Static(_) | hir::def::DefKind::Const, |
| def_id, |
| ), |
| .. |
| }, |
| )) => { |
| if let Some(hir::Node::Item(hir::Item { |
| ident, |
| kind: hir::ItemKind::Static(ty, ..) | hir::ItemKind::Const(ty, ..), |
| .. |
| })) = self.tcx.hir().get_if_local(*def_id) |
| { |
| primary_span = ty.span; |
| secondary_span = ident.span; |
| post_message = " type"; |
| } |
| } |
| hir::ExprKind::Path(hir::QPath::Resolved( |
| None, |
| hir::Path { res: hir::def::Res::Local(hir_id), .. }, |
| )) => { |
| if let Some(hir::Node::Pat(pat)) = self.tcx.hir().find(*hir_id) { |
| let parent = self.tcx.hir().get_parent_node(pat.hir_id); |
| primary_span = pat.span; |
| secondary_span = pat.span; |
| match self.tcx.hir().find(parent) { |
| Some(hir::Node::Local(hir::Local { ty: Some(ty), .. })) => { |
| primary_span = ty.span; |
| post_message = " type"; |
| } |
| Some(hir::Node::Local(hir::Local { init: Some(init), .. })) => { |
| primary_span = init.span; |
| post_message = " value"; |
| } |
| Some(hir::Node::Param(hir::Param { ty_span, .. })) => { |
| primary_span = *ty_span; |
| post_message = " parameter type"; |
| } |
| _ => {} |
| } |
| } |
| } |
| _ => {} |
| } |
| |
| if primary_span != secondary_span |
| && self |
| .tcx |
| .sess |
| .source_map() |
| .is_multiline(secondary_span.shrink_to_hi().until(primary_span)) |
| { |
| // We are pointing at the binding's type or initializer value, but it's pattern |
| // is in a different line, so we point at both. |
| err.span_label(secondary_span, "expected due to the type of this binding"); |
| err.span_label(primary_span, &format!("expected due to this{post_message}")); |
| } else if post_message == "" { |
| // We are pointing at either the assignment lhs or the binding def pattern. |
| err.span_label(primary_span, "expected due to the type of this binding"); |
| } else { |
| // We are pointing at the binding's type or initializer value. |
| err.span_label(primary_span, &format!("expected due to this{post_message}")); |
| } |
| |
| if !lhs.is_syntactic_place_expr() { |
| // We already emitted E0070 "invalid left-hand side of assignment", so we |
| // silence this. |
| err.downgrade_to_delayed_bug(); |
| } |
| } |
| _ => {} |
| } |
| } |
| |
| /// If the expected type is an enum (Issue #55250) with any variants whose |
| /// sole field is of the found type, suggest such variants. (Issue #42764) |
| fn suggest_compatible_variants( |
| &self, |
| err: &mut Diagnostic, |
| expr: &hir::Expr<'_>, |
| expected: Ty<'tcx>, |
| expr_ty: Ty<'tcx>, |
| ) { |
| if let ty::Adt(expected_adt, substs) = expected.kind() { |
| if let hir::ExprKind::Field(base, ident) = expr.kind { |
| let base_ty = self.typeck_results.borrow().expr_ty(base); |
| if self.can_eq(self.param_env, base_ty, expected).is_ok() |
| && let Some(base_span) = base.span.find_ancestor_inside(expr.span) |
| { |
| err.span_suggestion_verbose( |
| expr.span.with_lo(base_span.hi()), |
| format!("consider removing the tuple struct field `{ident}`"), |
| "", |
| Applicability::MaybeIncorrect, |
| ); |
| return |
| } |
| } |
| |
| // If the expression is of type () and it's the return expression of a block, |
| // we suggest adding a separate return expression instead. |
| // (To avoid things like suggesting `Ok(while .. { .. })`.) |
| if expr_ty.is_unit() { |
| let mut id = expr.hir_id; |
| let mut parent; |
| |
| // Unroll desugaring, to make sure this works for `for` loops etc. |
| loop { |
| parent = self.tcx.hir().get_parent_node(id); |
| if let Some(parent_span) = self.tcx.hir().opt_span(parent) { |
| if parent_span.find_ancestor_inside(expr.span).is_some() { |
| // The parent node is part of the same span, so is the result of the |
| // same expansion/desugaring and not the 'real' parent node. |
| id = parent; |
| continue; |
| } |
| } |
| break; |
| } |
| |
| if let Some(hir::Node::Block(&hir::Block { |
| span: block_span, expr: Some(e), .. |
| })) = self.tcx.hir().find(parent) |
| { |
| if e.hir_id == id { |
| if let Some(span) = expr.span.find_ancestor_inside(block_span) { |
| let return_suggestions = if self |
| .tcx |
| .is_diagnostic_item(sym::Result, expected_adt.did()) |
| { |
| vec!["Ok(())"] |
| } else if self.tcx.is_diagnostic_item(sym::Option, expected_adt.did()) { |
| vec!["None", "Some(())"] |
| } else { |
| return; |
| }; |
| if let Some(indent) = |
| self.tcx.sess.source_map().indentation_before(span.shrink_to_lo()) |
| { |
| // Add a semicolon, except after `}`. |
| let semicolon = |
| match self.tcx.sess.source_map().span_to_snippet(span) { |
| Ok(s) if s.ends_with('}') => "", |
| _ => ";", |
| }; |
| err.span_suggestions( |
| span.shrink_to_hi(), |
| "try adding an expression at the end of the block", |
| return_suggestions |
| .into_iter() |
| .map(|r| format!("{semicolon}\n{indent}{r}")), |
| Applicability::MaybeIncorrect, |
| ); |
| } |
| return; |
| } |
| } |
| } |
| } |
| |
| let compatible_variants: Vec<(String, _, _, Option<String>)> = expected_adt |
| .variants() |
| .iter() |
| .filter(|variant| { |
| variant.fields.len() == 1 |
| }) |
| .filter_map(|variant| { |
| let sole_field = &variant.fields[0]; |
| |
| let field_is_local = sole_field.did.is_local(); |
| let field_is_accessible = |
| sole_field.vis.is_accessible_from(expr.hir_id.owner, self.tcx) |
| // Skip suggestions for unstable public fields (for example `Pin::pointer`) |
| && matches!(self.tcx.eval_stability(sole_field.did, None, expr.span, None), EvalResult::Allow | EvalResult::Unmarked); |
| |
| if !field_is_local && !field_is_accessible { |
| return None; |
| } |
| |
| let note_about_variant_field_privacy = (field_is_local && !field_is_accessible) |
| .then(|| format!(" (its field is private, but it's local to this crate and its privacy can be changed)")); |
| |
| let sole_field_ty = sole_field.ty(self.tcx, substs); |
| if self.can_coerce(expr_ty, sole_field_ty) { |
| let variant_path = |
| with_no_trimmed_paths!(self.tcx.def_path_str(variant.def_id)); |
| // FIXME #56861: DRYer prelude filtering |
| if let Some(path) = variant_path.strip_prefix("std::prelude::") |
| && let Some((_, path)) = path.split_once("::") |
| { |
| return Some((path.to_string(), variant.ctor_kind, sole_field.name, note_about_variant_field_privacy)); |
| } |
| Some((variant_path, variant.ctor_kind, sole_field.name, note_about_variant_field_privacy)) |
| } else { |
| None |
| } |
| }) |
| .collect(); |
| |
| let suggestions_for = |variant: &_, ctor, field_name| { |
| let prefix = match self.maybe_get_struct_pattern_shorthand_field(expr) { |
| Some(ident) => format!("{ident}: "), |
| None => String::new(), |
| }; |
| |
| let (open, close) = match ctor { |
| hir::def::CtorKind::Fn => ("(".to_owned(), ")"), |
| hir::def::CtorKind::Fictive => (format!(" {{ {field_name}: "), " }"), |
| |
| // unit variants don't have fields |
| hir::def::CtorKind::Const => unreachable!(), |
| }; |
| |
| vec![ |
| (expr.span.shrink_to_lo(), format!("{prefix}{variant}{open}")), |
| (expr.span.shrink_to_hi(), close.to_owned()), |
| ] |
| }; |
| |
| match &compatible_variants[..] { |
| [] => { /* No variants to format */ } |
| [(variant, ctor_kind, field_name, note)] => { |
| // Just a single matching variant. |
| err.multipart_suggestion_verbose( |
| &format!( |
| "try wrapping the expression in `{variant}`{note}", |
| note = note.as_deref().unwrap_or("") |
| ), |
| suggestions_for(&**variant, *ctor_kind, *field_name), |
| Applicability::MaybeIncorrect, |
| ); |
| } |
| _ => { |
| // More than one matching variant. |
| err.multipart_suggestions( |
| &format!( |
| "try wrapping the expression in a variant of `{}`", |
| self.tcx.def_path_str(expected_adt.did()) |
| ), |
| compatible_variants.into_iter().map( |
| |(variant, ctor_kind, field_name, _)| { |
| suggestions_for(&variant, ctor_kind, field_name) |
| }, |
| ), |
| Applicability::MaybeIncorrect, |
| ); |
| } |
| } |
| } |
| } |
| |
| fn suggest_non_zero_new_unwrap( |
| &self, |
| err: &mut Diagnostic, |
| expr: &hir::Expr<'_>, |
| expected: Ty<'tcx>, |
| expr_ty: Ty<'tcx>, |
| ) { |
| let tcx = self.tcx; |
| let (adt, unwrap) = match expected.kind() { |
| // In case Option<NonZero*> is wanted, but * is provided, suggest calling new |
| ty::Adt(adt, substs) if tcx.is_diagnostic_item(sym::Option, adt.did()) => { |
| // Unwrap option |
| let ty::Adt(adt, _) = substs.type_at(0).kind() else { return }; |
| |
| (adt, "") |
| } |
| // In case NonZero* is wanted, but * is provided also add `.unwrap()` to satisfy types |
| ty::Adt(adt, _) => (adt, ".unwrap()"), |
| _ => return, |
| }; |
| |
| let map = [ |
| (sym::NonZeroU8, tcx.types.u8), |
| (sym::NonZeroU16, tcx.types.u16), |
| (sym::NonZeroU32, tcx.types.u32), |
| (sym::NonZeroU64, tcx.types.u64), |
| (sym::NonZeroU128, tcx.types.u128), |
| (sym::NonZeroI8, tcx.types.i8), |
| (sym::NonZeroI16, tcx.types.i16), |
| (sym::NonZeroI32, tcx.types.i32), |
| (sym::NonZeroI64, tcx.types.i64), |
| (sym::NonZeroI128, tcx.types.i128), |
| ]; |
| |
| let Some((s, _)) = map |
| .iter() |
| .find(|&&(s, t)| self.tcx.is_diagnostic_item(s, adt.did()) && self.can_coerce(expr_ty, t)) |
| else { return }; |
| |
| let path = self.tcx.def_path_str(adt.non_enum_variant().def_id); |
| |
| err.multipart_suggestion( |
| format!("consider calling `{s}::new`"), |
| vec![ |
| (expr.span.shrink_to_lo(), format!("{path}::new(")), |
| (expr.span.shrink_to_hi(), format!("){unwrap}")), |
| ], |
| Applicability::MaybeIncorrect, |
| ); |
| } |
| |
| pub fn get_conversion_methods( |
| &self, |
| span: Span, |
| expected: Ty<'tcx>, |
| checked_ty: Ty<'tcx>, |
| hir_id: hir::HirId, |
| ) -> Vec<AssocItem> { |
| let mut methods = |
| self.probe_for_return_type(span, probe::Mode::MethodCall, expected, checked_ty, hir_id); |
| methods.retain(|m| { |
| self.has_only_self_parameter(m) |
| && self |
| .tcx |
| // This special internal attribute is used to permit |
| // "identity-like" conversion methods to be suggested here. |
| // |
| // FIXME (#46459 and #46460): ideally |
| // `std::convert::Into::into` and `std::borrow:ToOwned` would |
| // also be `#[rustc_conversion_suggestion]`, if not for |
| // method-probing false-positives and -negatives (respectively). |
| // |
| // FIXME? Other potential candidate methods: `as_ref` and |
| // `as_mut`? |
| .has_attr(m.def_id, sym::rustc_conversion_suggestion) |
| }); |
| |
| methods |
| } |
| |
| /// This function checks whether the method is not static and does not accept other parameters than `self`. |
| fn has_only_self_parameter(&self, method: &AssocItem) -> bool { |
| match method.kind { |
| ty::AssocKind::Fn => { |
| method.fn_has_self_parameter |
| && self.tcx.fn_sig(method.def_id).inputs().skip_binder().len() == 1 |
| } |
| _ => false, |
| } |
| } |
| |
| /// Identify some cases where `as_ref()` would be appropriate and suggest it. |
| /// |
| /// Given the following code: |
| /// ```compile_fail,E0308 |
| /// struct Foo; |
| /// fn takes_ref(_: &Foo) {} |
| /// let ref opt = Some(Foo); |
| /// |
| /// opt.map(|param| takes_ref(param)); |
| /// ``` |
| /// Suggest using `opt.as_ref().map(|param| takes_ref(param));` instead. |
| /// |
| /// It only checks for `Option` and `Result` and won't work with |
| /// ```ignore (illustrative) |
| /// opt.map(|param| { takes_ref(param) }); |
| /// ``` |
| fn can_use_as_ref(&self, expr: &hir::Expr<'_>) -> Option<(Span, &'static str, String)> { |
| let hir::ExprKind::Path(hir::QPath::Resolved(_, ref path)) = expr.kind else { |
| return None; |
| }; |
| |
| let hir::def::Res::Local(local_id) = path.res else { |
| return None; |
| }; |
| |
| let local_parent = self.tcx.hir().get_parent_node(local_id); |
| let Some(Node::Param(hir::Param { hir_id: param_hir_id, .. })) = self.tcx.hir().find(local_parent) else { |
| return None; |
| }; |
| |
| let param_parent = self.tcx.hir().get_parent_node(*param_hir_id); |
| let Some(Node::Expr(hir::Expr { |
| hir_id: expr_hir_id, |
| kind: hir::ExprKind::Closure(hir::Closure { fn_decl: closure_fn_decl, .. }), |
| .. |
| })) = self.tcx.hir().find(param_parent) else { |
| return None; |
| }; |
| |
| let expr_parent = self.tcx.hir().get_parent_node(*expr_hir_id); |
| let hir = self.tcx.hir().find(expr_parent); |
| let closure_params_len = closure_fn_decl.inputs.len(); |
| let ( |
| Some(Node::Expr(hir::Expr { |
| kind: hir::ExprKind::MethodCall(method_path, receiver, ..), |
| .. |
| })), |
| 1, |
| ) = (hir, closure_params_len) else { |
| return None; |
| }; |
| |
| let self_ty = self.typeck_results.borrow().expr_ty(receiver); |
| let name = method_path.ident.name; |
| let is_as_ref_able = match self_ty.peel_refs().kind() { |
| ty::Adt(def, _) => { |
| (self.tcx.is_diagnostic_item(sym::Option, def.did()) |
| || self.tcx.is_diagnostic_item(sym::Result, def.did())) |
| && (name == sym::map || name == sym::and_then) |
| } |
| _ => false, |
| }; |
| match (is_as_ref_able, self.sess().source_map().span_to_snippet(method_path.ident.span)) { |
| (true, Ok(src)) => { |
| let suggestion = format!("as_ref().{}", src); |
| Some((method_path.ident.span, "consider using `as_ref` instead", suggestion)) |
| } |
| _ => None, |
| } |
| } |
| |
| pub(crate) fn maybe_get_struct_pattern_shorthand_field( |
| &self, |
| expr: &hir::Expr<'_>, |
| ) -> Option<Symbol> { |
| let hir = self.tcx.hir(); |
| let local = match expr { |
| hir::Expr { |
| kind: |
| hir::ExprKind::Path(hir::QPath::Resolved( |
| None, |
| hir::Path { |
| res: hir::def::Res::Local(_), |
| segments: [hir::PathSegment { ident, .. }], |
| .. |
| }, |
| )), |
| .. |
| } => Some(ident), |
| _ => None, |
| }?; |
| |
| match hir.find(hir.get_parent_node(expr.hir_id))? { |
| Node::ExprField(field) => { |
| if field.ident.name == local.name && field.is_shorthand { |
| return Some(local.name); |
| } |
| } |
| _ => {} |
| } |
| |
| None |
| } |
| |
| /// If the given `HirId` corresponds to a block with a trailing expression, return that expression |
| pub(crate) fn maybe_get_block_expr( |
| &self, |
| expr: &hir::Expr<'tcx>, |
| ) -> Option<&'tcx hir::Expr<'tcx>> { |
| match expr { |
| hir::Expr { kind: hir::ExprKind::Block(block, ..), .. } => block.expr, |
| _ => None, |
| } |
| } |
| |
| /// Returns whether the given expression is an `else if`. |
| pub(crate) fn is_else_if_block(&self, expr: &hir::Expr<'_>) -> bool { |
| if let hir::ExprKind::If(..) = expr.kind { |
| let parent_id = self.tcx.hir().get_parent_node(expr.hir_id); |
| if let Some(Node::Expr(hir::Expr { |
| kind: hir::ExprKind::If(_, _, Some(else_expr)), |
| .. |
| })) = self.tcx.hir().find(parent_id) |
| { |
| return else_expr.hir_id == expr.hir_id; |
| } |
| } |
| false |
| } |
| |
| /// This function is used to determine potential "simple" improvements or users' errors and |
| /// provide them useful help. For example: |
| /// |
| /// ```compile_fail,E0308 |
| /// fn some_fn(s: &str) {} |
| /// |
| /// let x = "hey!".to_owned(); |
| /// some_fn(x); // error |
| /// ``` |
| /// |
| /// No need to find every potential function which could make a coercion to transform a |
| /// `String` into a `&str` since a `&` would do the trick! |
| /// |
| /// In addition of this check, it also checks between references mutability state. If the |
| /// expected is mutable but the provided isn't, maybe we could just say "Hey, try with |
| /// `&mut`!". |
| pub fn check_ref( |
| &self, |
| expr: &hir::Expr<'tcx>, |
| checked_ty: Ty<'tcx>, |
| expected: Ty<'tcx>, |
| ) -> Option<(Span, String, String, Applicability, bool /* verbose */)> { |
| let sess = self.sess(); |
| let sp = expr.span; |
| |
| // If the span is from an external macro, there's no suggestion we can make. |
| if in_external_macro(sess, sp) { |
| return None; |
| } |
| |
| let sm = sess.source_map(); |
| |
| let replace_prefix = |s: &str, old: &str, new: &str| { |
| s.strip_prefix(old).map(|stripped| new.to_string() + stripped) |
| }; |
| |
| // `ExprKind::DropTemps` is semantically irrelevant for these suggestions. |
| let expr = expr.peel_drop_temps(); |
| |
| match (&expr.kind, expected.kind(), checked_ty.kind()) { |
| (_, &ty::Ref(_, exp, _), &ty::Ref(_, check, _)) => match (exp.kind(), check.kind()) { |
| (&ty::Str, &ty::Array(arr, _) | &ty::Slice(arr)) if arr == self.tcx.types.u8 => { |
| if let hir::ExprKind::Lit(_) = expr.kind |
| && let Ok(src) = sm.span_to_snippet(sp) |
| && replace_prefix(&src, "b\"", "\"").is_some() |
| { |
| let pos = sp.lo() + BytePos(1); |
| return Some(( |
| sp.with_hi(pos), |
| "consider removing the leading `b`".to_string(), |
| String::new(), |
| Applicability::MachineApplicable, |
| true, |
| )); |
| } |
| } |
| (&ty::Array(arr, _) | &ty::Slice(arr), &ty::Str) if arr == self.tcx.types.u8 => { |
| if let hir::ExprKind::Lit(_) = expr.kind |
| && let Ok(src) = sm.span_to_snippet(sp) |
| && replace_prefix(&src, "\"", "b\"").is_some() |
| { |
| return Some(( |
| sp.shrink_to_lo(), |
| "consider adding a leading `b`".to_string(), |
| "b".to_string(), |
| Applicability::MachineApplicable, |
| true, |
| )); |
| } |
| } |
| _ => {} |
| }, |
| (_, &ty::Ref(_, _, mutability), _) => { |
| // Check if it can work when put into a ref. For example: |
| // |
| // ``` |
| // fn bar(x: &mut i32) {} |
| // |
| // let x = 0u32; |
| // bar(&x); // error, expected &mut |
| // ``` |
| let ref_ty = match mutability { |
| hir::Mutability::Mut => { |
| self.tcx.mk_mut_ref(self.tcx.mk_region(ty::ReStatic), checked_ty) |
| } |
| hir::Mutability::Not => { |
| self.tcx.mk_imm_ref(self.tcx.mk_region(ty::ReStatic), checked_ty) |
| } |
| }; |
| if self.can_coerce(ref_ty, expected) { |
| let mut sugg_sp = sp; |
| if let hir::ExprKind::MethodCall(ref segment, receiver, args, _) = expr.kind { |
| let clone_trait = |
| self.tcx.require_lang_item(LangItem::Clone, Some(segment.ident.span)); |
| if args.is_empty() |
| && self.typeck_results.borrow().type_dependent_def_id(expr.hir_id).map( |
| |did| { |
| let ai = self.tcx.associated_item(did); |
| ai.trait_container(self.tcx) == Some(clone_trait) |
| }, |
| ) == Some(true) |
| && segment.ident.name == sym::clone |
| { |
| // If this expression had a clone call when suggesting borrowing |
| // we want to suggest removing it because it'd now be unnecessary. |
| sugg_sp = receiver.span; |
| } |
| } |
| if let Ok(src) = sm.span_to_snippet(sugg_sp) { |
| let needs_parens = match expr.kind { |
| // parenthesize if needed (Issue #46756) |
| hir::ExprKind::Cast(_, _) | hir::ExprKind::Binary(_, _, _) => true, |
| // parenthesize borrows of range literals (Issue #54505) |
| _ if is_range_literal(expr) => true, |
| _ => false, |
| }; |
| |
| if let Some(sugg) = self.can_use_as_ref(expr) { |
| return Some(( |
| sugg.0, |
| sugg.1.to_string(), |
| sugg.2, |
| Applicability::MachineApplicable, |
| false, |
| )); |
| } |
| |
| let prefix = match self.maybe_get_struct_pattern_shorthand_field(expr) { |
| Some(ident) => format!("{ident}: "), |
| None => String::new(), |
| }; |
| |
| if let Some(hir::Node::Expr(hir::Expr { |
| kind: hir::ExprKind::Assign(..), |
| .. |
| })) = self.tcx.hir().find(self.tcx.hir().get_parent_node(expr.hir_id)) |
| { |
| if mutability == hir::Mutability::Mut { |
| // Suppressing this diagnostic, we'll properly print it in `check_expr_assign` |
| return None; |
| } |
| } |
| |
| let sugg_expr = if needs_parens { format!("({src})") } else { src }; |
| return Some(match mutability { |
| hir::Mutability::Mut => ( |
| sp, |
| "consider mutably borrowing here".to_string(), |
| format!("{prefix}&mut {sugg_expr}"), |
| Applicability::MachineApplicable, |
| false, |
| ), |
| hir::Mutability::Not => ( |
| sp, |
| "consider borrowing here".to_string(), |
| format!("{prefix}&{sugg_expr}"), |
| Applicability::MachineApplicable, |
| false, |
| ), |
| }); |
| } |
| } |
| } |
| ( |
| hir::ExprKind::AddrOf(hir::BorrowKind::Ref, _, ref expr), |
| _, |
| &ty::Ref(_, checked, _), |
| ) if self.can_sub(self.param_env, checked, expected).is_ok() => { |
| // We have `&T`, check if what was expected was `T`. If so, |
| // we may want to suggest removing a `&`. |
| if sm.is_imported(expr.span) { |
| // Go through the spans from which this span was expanded, |
| // and find the one that's pointing inside `sp`. |
| // |
| // E.g. for `&format!("")`, where we want the span to the |
| // `format!()` invocation instead of its expansion. |
| if let Some(call_span) = |
| iter::successors(Some(expr.span), |s| s.parent_callsite()) |
| .find(|&s| sp.contains(s)) |
| && sm.is_span_accessible(call_span) |
| { |
| return Some(( |
| sp.with_hi(call_span.lo()), |
| "consider removing the borrow".to_string(), |
| String::new(), |
| Applicability::MachineApplicable, |
| true, |
| )); |
| } |
| return None; |
| } |
| if sp.contains(expr.span) |
| && sm.is_span_accessible(expr.span) |
| { |
| return Some(( |
| sp.with_hi(expr.span.lo()), |
| "consider removing the borrow".to_string(), |
| String::new(), |
| Applicability::MachineApplicable, |
| true, |
| )); |
| } |
| } |
| ( |
| _, |
| &ty::RawPtr(TypeAndMut { ty: ty_b, mutbl: mutbl_b }), |
| &ty::Ref(_, ty_a, mutbl_a), |
| ) => { |
| if let Some(steps) = self.deref_steps(ty_a, ty_b) |
| // Only suggest valid if dereferencing needed. |
| && steps > 0 |
| // The pointer type implements `Copy` trait so the suggestion is always valid. |
| && let Ok(src) = sm.span_to_snippet(sp) |
| { |
| let derefs = "*".repeat(steps); |
| if let Some((span, src, applicability)) = match mutbl_b { |
| hir::Mutability::Mut => { |
| let new_prefix = "&mut ".to_owned() + &derefs; |
| match mutbl_a { |
| hir::Mutability::Mut => { |
| replace_prefix(&src, "&mut ", &new_prefix).map(|_| { |
| let pos = sp.lo() + BytePos(5); |
| let sp = sp.with_lo(pos).with_hi(pos); |
| (sp, derefs, Applicability::MachineApplicable) |
| }) |
| } |
| hir::Mutability::Not => { |
| replace_prefix(&src, "&", &new_prefix).map(|_| { |
| let pos = sp.lo() + BytePos(1); |
| let sp = sp.with_lo(pos).with_hi(pos); |
| ( |
| sp, |
| format!("mut {derefs}"), |
| Applicability::Unspecified, |
| ) |
| }) |
| } |
| } |
| } |
| hir::Mutability::Not => { |
| let new_prefix = "&".to_owned() + &derefs; |
| match mutbl_a { |
| hir::Mutability::Mut => { |
| replace_prefix(&src, "&mut ", &new_prefix).map(|_| { |
| let lo = sp.lo() + BytePos(1); |
| let hi = sp.lo() + BytePos(5); |
| let sp = sp.with_lo(lo).with_hi(hi); |
| (sp, derefs, Applicability::MachineApplicable) |
| }) |
| } |
| hir::Mutability::Not => { |
| replace_prefix(&src, "&", &new_prefix).map(|_| { |
| let pos = sp.lo() + BytePos(1); |
| let sp = sp.with_lo(pos).with_hi(pos); |
| (sp, derefs, Applicability::MachineApplicable) |
| }) |
| } |
| } |
| } |
| } { |
| return Some(( |
| span, |
| "consider dereferencing".to_string(), |
| src, |
| applicability, |
| true, |
| )); |
| } |
| } |
| } |
| _ if sp == expr.span => { |
| if let Some(mut steps) = self.deref_steps(checked_ty, expected) { |
| let mut expr = expr.peel_blocks(); |
| let mut prefix_span = expr.span.shrink_to_lo(); |
| let mut remove = String::new(); |
| |
| // Try peeling off any existing `&` and `&mut` to reach our target type |
| while steps > 0 { |
| if let hir::ExprKind::AddrOf(_, mutbl, inner) = expr.kind { |
| // If the expression has `&`, removing it would fix the error |
| prefix_span = prefix_span.with_hi(inner.span.lo()); |
| expr = inner; |
| remove += match mutbl { |
| hir::Mutability::Not => "&", |
| hir::Mutability::Mut => "&mut ", |
| }; |
| steps -= 1; |
| } else { |
| break; |
| } |
| } |
| // If we've reached our target type with just removing `&`, then just print now. |
| if steps == 0 { |
| return Some(( |
| prefix_span, |
| format!("consider removing the `{}`", remove.trim()), |
| String::new(), |
| // Do not remove `&&` to get to bool, because it might be something like |
| // { a } && b, which we have a separate fixup suggestion that is more |
| // likely correct... |
| if remove.trim() == "&&" && expected == self.tcx.types.bool { |
| Applicability::MaybeIncorrect |
| } else { |
| Applicability::MachineApplicable |
| }, |
| true, |
| )); |
| } |
| |
| // For this suggestion to make sense, the type would need to be `Copy`, |
| // or we have to be moving out of a `Box<T>` |
| if self.type_is_copy_modulo_regions(self.param_env, expected, sp) |
| // FIXME(compiler-errors): We can actually do this if the checked_ty is |
| // `steps` layers of boxes, not just one, but this is easier and most likely. |
| || (checked_ty.is_box() && steps == 1) |
| { |
| let deref_kind = if checked_ty.is_box() { |
| "unboxing the value" |
| } else if checked_ty.is_region_ptr() { |
| "dereferencing the borrow" |
| } else { |
| "dereferencing the type" |
| }; |
| |
| // Suggest removing `&` if we have removed any, otherwise suggest just |
| // dereferencing the remaining number of steps. |
| let message = if remove.is_empty() { |
| format!("consider {deref_kind}") |
| } else { |
| format!( |
| "consider removing the `{}` and {} instead", |
| remove.trim(), |
| deref_kind |
| ) |
| }; |
| |
| let prefix = match self.maybe_get_struct_pattern_shorthand_field(expr) { |
| Some(ident) => format!("{ident}: "), |
| None => String::new(), |
| }; |
| |
| let (span, suggestion) = if self.is_else_if_block(expr) { |
| // Don't suggest nonsense like `else *if` |
| return None; |
| } else if let Some(expr) = self.maybe_get_block_expr(expr) { |
| // prefix should be empty here.. |
| (expr.span.shrink_to_lo(), "*".to_string()) |
| } else { |
| (prefix_span, format!("{}{}", prefix, "*".repeat(steps))) |
| }; |
| |
| return Some(( |
| span, |
| message, |
| suggestion, |
| Applicability::MachineApplicable, |
| true, |
| )); |
| } |
| } |
| } |
| _ => {} |
| } |
| None |
| } |
| |
| pub fn check_for_cast( |
| &self, |
| err: &mut Diagnostic, |
| expr: &hir::Expr<'_>, |
| checked_ty: Ty<'tcx>, |
| expected_ty: Ty<'tcx>, |
| expected_ty_expr: Option<&'tcx hir::Expr<'tcx>>, |
| ) -> bool { |
| if self.tcx.sess.source_map().is_imported(expr.span) { |
| // Ignore if span is from within a macro. |
| return false; |
| } |
| |
| let Ok(src) = self.tcx.sess.source_map().span_to_snippet(expr.span) else { |
| return false; |
| }; |
| |
| // If casting this expression to a given numeric type would be appropriate in case of a type |
| // mismatch. |
| // |
| // We want to minimize the amount of casting operations that are suggested, as it can be a |
| // lossy operation with potentially bad side effects, so we only suggest when encountering |
| // an expression that indicates that the original type couldn't be directly changed. |
| // |
| // For now, don't suggest casting with `as`. |
| let can_cast = false; |
| |
| let mut sugg = vec![]; |
| |
| if let Some(hir::Node::ExprField(field)) = |
| self.tcx.hir().find(self.tcx.hir().get_parent_node(expr.hir_id)) |
| { |
| // `expr` is a literal field for a struct, only suggest if appropriate |
| if field.is_shorthand { |
| // This is a field literal |
| sugg.push((field.ident.span.shrink_to_lo(), format!("{}: ", field.ident))); |
| } else { |
| // Likely a field was meant, but this field wasn't found. Do not suggest anything. |
| return false; |
| } |
| }; |
| |
| if let hir::ExprKind::Call(path, args) = &expr.kind |
| && let (hir::ExprKind::Path(hir::QPath::TypeRelative(base_ty, path_segment)), 1) = |
| (&path.kind, args.len()) |
| // `expr` is a conversion like `u32::from(val)`, do not suggest anything (#63697). |
| && let (hir::TyKind::Path(hir::QPath::Resolved(None, base_ty_path)), sym::from) = |
| (&base_ty.kind, path_segment.ident.name) |
| { |
| if let Some(ident) = &base_ty_path.segments.iter().map(|s| s.ident).next() { |
| match ident.name { |
| sym::i128 |
| | sym::i64 |
| | sym::i32 |
| | sym::i16 |
| | sym::i8 |
| | sym::u128 |
| | sym::u64 |
| | sym::u32 |
| | sym::u16 |
| | sym::u8 |
| | sym::isize |
| | sym::usize |
| if base_ty_path.segments.len() == 1 => |
| { |
| return false; |
| } |
| _ => {} |
| } |
| } |
| } |
| |
| let msg = format!( |
| "you can convert {} `{}` to {} `{}`", |
| checked_ty.kind().article(), |
| checked_ty, |
| expected_ty.kind().article(), |
| expected_ty, |
| ); |
| let cast_msg = format!( |
| "you can cast {} `{}` to {} `{}`", |
| checked_ty.kind().article(), |
| checked_ty, |
| expected_ty.kind().article(), |
| expected_ty, |
| ); |
| let lit_msg = format!( |
| "change the type of the numeric literal from `{checked_ty}` to `{expected_ty}`", |
| ); |
| |
| let close_paren = if expr.precedence().order() < PREC_POSTFIX { |
| sugg.push((expr.span.shrink_to_lo(), "(".to_string())); |
| ")" |
| } else { |
| "" |
| }; |
| |
| let mut cast_suggestion = sugg.clone(); |
| cast_suggestion.push((expr.span.shrink_to_hi(), format!("{close_paren} as {expected_ty}"))); |
| let mut into_suggestion = sugg.clone(); |
| into_suggestion.push((expr.span.shrink_to_hi(), format!("{close_paren}.into()"))); |
| let mut suffix_suggestion = sugg.clone(); |
| suffix_suggestion.push(( |
| if matches!( |
| (&expected_ty.kind(), &checked_ty.kind()), |
| (ty::Int(_) | ty::Uint(_), ty::Float(_)) |
| ) { |
| // Remove fractional part from literal, for example `42.0f32` into `42` |
| let src = src.trim_end_matches(&checked_ty.to_string()); |
| let len = src.split('.').next().unwrap().len(); |
| expr.span.with_lo(expr.span.lo() + BytePos(len as u32)) |
| } else { |
| let len = src.trim_end_matches(&checked_ty.to_string()).len(); |
| expr.span.with_lo(expr.span.lo() + BytePos(len as u32)) |
| }, |
| if expr.precedence().order() < PREC_POSTFIX { |
| // Readd `)` |
| format!("{expected_ty})") |
| } else { |
| expected_ty.to_string() |
| }, |
| )); |
| let literal_is_ty_suffixed = |expr: &hir::Expr<'_>| { |
| if let hir::ExprKind::Lit(lit) = &expr.kind { lit.node.is_suffixed() } else { false } |
| }; |
| let is_negative_int = |
| |expr: &hir::Expr<'_>| matches!(expr.kind, hir::ExprKind::Unary(hir::UnOp::Neg, ..)); |
| let is_uint = |ty: Ty<'_>| matches!(ty.kind(), ty::Uint(..)); |
| |
| let in_const_context = self.tcx.hir().is_inside_const_context(expr.hir_id); |
| |
| let suggest_fallible_into_or_lhs_from = |
| |err: &mut Diagnostic, exp_to_found_is_fallible: bool| { |
| // If we know the expression the expected type is derived from, we might be able |
| // to suggest a widening conversion rather than a narrowing one (which may |
| // panic). For example, given x: u8 and y: u32, if we know the span of "x", |
| // x > y |
| // can be given the suggestion "u32::from(x) > y" rather than |
| // "x > y.try_into().unwrap()". |
| let lhs_expr_and_src = expected_ty_expr.and_then(|expr| { |
| self.tcx |
| .sess |
| .source_map() |
| .span_to_snippet(expr.span) |
| .ok() |
| .map(|src| (expr, src)) |
| }); |
| let (msg, suggestion) = if let (Some((lhs_expr, lhs_src)), false) = |
| (lhs_expr_and_src, exp_to_found_is_fallible) |
| { |
| let msg = format!( |
| "you can convert `{lhs_src}` from `{expected_ty}` to `{checked_ty}`, matching the type of `{src}`", |
| ); |
| let suggestion = vec![ |
| (lhs_expr.span.shrink_to_lo(), format!("{checked_ty}::from(")), |
| (lhs_expr.span.shrink_to_hi(), ")".to_string()), |
| ]; |
| (msg, suggestion) |
| } else { |
| let msg = format!("{msg} and panic if the converted value doesn't fit"); |
| let mut suggestion = sugg.clone(); |
| suggestion.push(( |
| expr.span.shrink_to_hi(), |
| format!("{close_paren}.try_into().unwrap()"), |
| )); |
| (msg, suggestion) |
| }; |
| err.multipart_suggestion_verbose( |
| &msg, |
| suggestion, |
| Applicability::MachineApplicable, |
| ); |
| }; |
| |
| let suggest_to_change_suffix_or_into = |
| |err: &mut Diagnostic, |
| found_to_exp_is_fallible: bool, |
| exp_to_found_is_fallible: bool| { |
| let exp_is_lhs = |
| expected_ty_expr.map(|e| self.tcx.hir().is_lhs(e.hir_id)).unwrap_or(false); |
| |
| if exp_is_lhs { |
| return; |
| } |
| |
| let always_fallible = found_to_exp_is_fallible |
| && (exp_to_found_is_fallible || expected_ty_expr.is_none()); |
| let msg = if literal_is_ty_suffixed(expr) { |
| &lit_msg |
| } else if always_fallible && (is_negative_int(expr) && is_uint(expected_ty)) { |
| // We now know that converting either the lhs or rhs is fallible. Before we |
| // suggest a fallible conversion, check if the value can never fit in the |
| // expected type. |
| let msg = format!("`{src}` cannot fit into type `{expected_ty}`"); |
| err.note(&msg); |
| return; |
| } else if in_const_context { |
| // Do not recommend `into` or `try_into` in const contexts. |
| return; |
| } else if found_to_exp_is_fallible { |
| return suggest_fallible_into_or_lhs_from(err, exp_to_found_is_fallible); |
| } else { |
| &msg |
| }; |
| let suggestion = if literal_is_ty_suffixed(expr) { |
| suffix_suggestion.clone() |
| } else { |
| into_suggestion.clone() |
| }; |
| err.multipart_suggestion_verbose(msg, suggestion, Applicability::MachineApplicable); |
| }; |
| |
| match (&expected_ty.kind(), &checked_ty.kind()) { |
| (&ty::Int(ref exp), &ty::Int(ref found)) => { |
| let (f2e_is_fallible, e2f_is_fallible) = match (exp.bit_width(), found.bit_width()) |
| { |
| (Some(exp), Some(found)) if exp < found => (true, false), |
| (Some(exp), Some(found)) if exp > found => (false, true), |
| (None, Some(8 | 16)) => (false, true), |
| (Some(8 | 16), None) => (true, false), |
| (None, _) | (_, None) => (true, true), |
| _ => (false, false), |
| }; |
| suggest_to_change_suffix_or_into(err, f2e_is_fallible, e2f_is_fallible); |
| true |
| } |
| (&ty::Uint(ref exp), &ty::Uint(ref found)) => { |
| let (f2e_is_fallible, e2f_is_fallible) = match (exp.bit_width(), found.bit_width()) |
| { |
| (Some(exp), Some(found)) if exp < found => (true, false), |
| (Some(exp), Some(found)) if exp > found => (false, true), |
| (None, Some(8 | 16)) => (false, true), |
| (Some(8 | 16), None) => (true, false), |
| (None, _) | (_, None) => (true, true), |
| _ => (false, false), |
| }; |
| suggest_to_change_suffix_or_into(err, f2e_is_fallible, e2f_is_fallible); |
| true |
| } |
| (&ty::Int(exp), &ty::Uint(found)) => { |
| let (f2e_is_fallible, e2f_is_fallible) = match (exp.bit_width(), found.bit_width()) |
| { |
| (Some(exp), Some(found)) if found < exp => (false, true), |
| (None, Some(8)) => (false, true), |
| _ => (true, true), |
| }; |
| suggest_to_change_suffix_or_into(err, f2e_is_fallible, e2f_is_fallible); |
| true |
| } |
| (&ty::Uint(exp), &ty::Int(found)) => { |
| let (f2e_is_fallible, e2f_is_fallible) = match (exp.bit_width(), found.bit_width()) |
| { |
| (Some(exp), Some(found)) if found > exp => (true, false), |
| (Some(8), None) => (true, false), |
| _ => (true, true), |
| }; |
| suggest_to_change_suffix_or_into(err, f2e_is_fallible, e2f_is_fallible); |
| true |
| } |
| (&ty::Float(ref exp), &ty::Float(ref found)) => { |
| if found.bit_width() < exp.bit_width() { |
| suggest_to_change_suffix_or_into(err, false, true); |
| } else if literal_is_ty_suffixed(expr) { |
| err.multipart_suggestion_verbose( |
| &lit_msg, |
| suffix_suggestion, |
| Applicability::MachineApplicable, |
| ); |
| } else if can_cast { |
| // Missing try_into implementation for `f64` to `f32` |
| err.multipart_suggestion_verbose( |
| &format!("{cast_msg}, producing the closest possible value"), |
| cast_suggestion, |
| Applicability::MaybeIncorrect, // lossy conversion |
| ); |
| } |
| true |
| } |
| (&ty::Uint(_) | &ty::Int(_), &ty::Float(_)) => { |
| if literal_is_ty_suffixed(expr) { |
| err.multipart_suggestion_verbose( |
| &lit_msg, |
| suffix_suggestion, |
| Applicability::MachineApplicable, |
| ); |
| } else if can_cast { |
| // Missing try_into implementation for `{float}` to `{integer}` |
| err.multipart_suggestion_verbose( |
| &format!("{msg}, rounding the float towards zero"), |
| cast_suggestion, |
| Applicability::MaybeIncorrect, // lossy conversion |
| ); |
| } |
| true |
| } |
| (&ty::Float(ref exp), &ty::Uint(ref found)) => { |
| // if `found` is `None` (meaning found is `usize`), don't suggest `.into()` |
| if exp.bit_width() > found.bit_width().unwrap_or(256) { |
| err.multipart_suggestion_verbose( |
| &format!( |
| "{msg}, producing the floating point representation of the integer", |
| ), |
| into_suggestion, |
| Applicability::MachineApplicable, |
| ); |
| } else if literal_is_ty_suffixed(expr) { |
| err.multipart_suggestion_verbose( |
| &lit_msg, |
| suffix_suggestion, |
| Applicability::MachineApplicable, |
| ); |
| } else { |
| // Missing try_into implementation for `{integer}` to `{float}` |
| err.multipart_suggestion_verbose( |
| &format!( |
| "{cast_msg}, producing the floating point representation of the integer, \ |
| rounded if necessary", |
| ), |
| cast_suggestion, |
| Applicability::MaybeIncorrect, // lossy conversion |
| ); |
| } |
| true |
| } |
| (&ty::Float(ref exp), &ty::Int(ref found)) => { |
| // if `found` is `None` (meaning found is `isize`), don't suggest `.into()` |
| if exp.bit_width() > found.bit_width().unwrap_or(256) { |
| err.multipart_suggestion_verbose( |
| &format!( |
| "{}, producing the floating point representation of the integer", |
| &msg, |
| ), |
| into_suggestion, |
| Applicability::MachineApplicable, |
| ); |
| } else if literal_is_ty_suffixed(expr) { |
| err.multipart_suggestion_verbose( |
| &lit_msg, |
| suffix_suggestion, |
| Applicability::MachineApplicable, |
| ); |
| } else { |
| // Missing try_into implementation for `{integer}` to `{float}` |
| err.multipart_suggestion_verbose( |
| &format!( |
| "{}, producing the floating point representation of the integer, \ |
| rounded if necessary", |
| &msg, |
| ), |
| cast_suggestion, |
| Applicability::MaybeIncorrect, // lossy conversion |
| ); |
| } |
| true |
| } |
| ( |
| &ty::Uint(ty::UintTy::U32 | ty::UintTy::U64 | ty::UintTy::U128) |
| | &ty::Int(ty::IntTy::I32 | ty::IntTy::I64 | ty::IntTy::I128), |
| &ty::Char, |
| ) => { |
| err.multipart_suggestion_verbose( |
| &format!("{cast_msg}, since a `char` always occupies 4 bytes"), |
| cast_suggestion, |
| Applicability::MachineApplicable, |
| ); |
| true |
| } |
| _ => false, |
| } |
| } |
| } |
