diff options
Diffstat (limited to 'compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs')
| -rw-r--r-- | compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs | 149 |
1 files changed, 119 insertions, 30 deletions
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs index 4db9c56f9..4f92477b5 100644 --- a/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs +++ b/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs @@ -10,24 +10,35 @@ use rustc_hir::{ Expr, ExprKind, GenericBound, Node, Path, QPath, Stmt, StmtKind, TyKind, WherePredicate, }; use rustc_hir_analysis::astconv::AstConv; -use rustc_infer::infer::{self, TyCtxtInferExt}; +use rustc_infer::infer; use rustc_infer::traits::{self, StatementAsExpression}; use rustc_middle::lint::in_external_macro; -use rustc_middle::ty::{self, Binder, IsSuggestable, ToPredicate, Ty}; +use rustc_middle::ty::{self, Binder, DefIdTree, IsSuggestable, ToPredicate, Ty}; use rustc_session::errors::ExprParenthesesNeeded; use rustc_span::symbol::sym; use rustc_span::Span; use rustc_trait_selection::infer::InferCtxtExt; use rustc_trait_selection::traits::error_reporting::DefIdOrName; use rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt as _; +use rustc_trait_selection::traits::NormalizeExt; impl<'a, 'tcx> FnCtxt<'a, 'tcx> { + pub(crate) fn body_fn_sig(&self) -> Option<ty::FnSig<'tcx>> { + self.typeck_results + .borrow() + .liberated_fn_sigs() + .get(self.tcx.hir().get_parent_node(self.body_id)) + .copied() + } + pub(in super::super) fn suggest_semicolon_at_end(&self, span: Span, err: &mut Diagnostic) { + // This suggestion is incorrect for + // fn foo() -> bool { match () { () => true } || match () { () => true } } err.span_suggestion_short( span.shrink_to_hi(), "consider using a semicolon here", ";", - Applicability::MachineApplicable, + Applicability::MaybeIncorrect, ); } @@ -165,7 +176,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { } ty::Opaque(def_id, substs) => { self.tcx.bound_item_bounds(def_id).subst(self.tcx, substs).iter().find_map(|pred| { - if let ty::PredicateKind::Projection(proj) = pred.kind().skip_binder() + if let ty::PredicateKind::Clause(ty::Clause::Projection(proj)) = pred.kind().skip_binder() && Some(proj.projection_ty.item_def_id) == self.tcx.lang_items().fn_once_output() // args tuple will always be substs[1] && let ty::Tuple(args) = proj.projection_ty.substs.type_at(1).kind() @@ -200,7 +211,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { ty::Param(param) => { let def_id = self.tcx.generics_of(self.body_id.owner).type_param(¶m, self.tcx).def_id; self.tcx.predicates_of(self.body_id.owner).predicates.iter().find_map(|(pred, _)| { - if let ty::PredicateKind::Projection(proj) = pred.kind().skip_binder() + if let ty::PredicateKind::Clause(ty::Clause::Projection(proj)) = pred.kind().skip_binder() && Some(proj.projection_ty.item_def_id) == self.tcx.lang_items().fn_once_output() && proj.projection_ty.self_ty() == found // args tuple will always be substs[1] @@ -237,7 +248,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { // implied by wf, but also because that would possibly result in // erroneous errors later on. let infer::InferOk { value: output, obligations: _ } = - self.normalize_associated_types_in_as_infer_ok(expr.span, output); + self.at(&self.misc(expr.span), self.param_env).normalize(output); if output.is_ty_var() { None } else { Some((def_id_or_name, output, inputs)) } } @@ -337,8 +348,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { } if annotation { let suggest_annotation = match expr.peel_drop_temps().kind { - hir::ExprKind::AddrOf(hir::BorrowKind::Ref, hir::Mutability::Not, _) => "&", - hir::ExprKind::AddrOf(hir::BorrowKind::Ref, hir::Mutability::Mut, _) => "&mut ", + hir::ExprKind::AddrOf(hir::BorrowKind::Ref, mutbl, _) => mutbl.ref_prefix_str(), _ => return true, }; let mut tuple_indexes = Vec::new(); @@ -366,7 +376,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { let annotation_span = ty.span; err.span_suggestion( annotation_span.with_hi(annotation_span.lo()), - format!("alternatively, consider changing the type annotation"), + "alternatively, consider changing the type annotation", suggest_annotation, Applicability::MaybeIncorrect, ); @@ -456,7 +466,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { ref_cnt += 1; } if let ty::Adt(adt, _) = peeled.kind() - && self.tcx.is_diagnostic_item(sym::String, adt.did()) + && Some(adt.did()) == self.tcx.lang_items().string() { err.span_suggestion_verbose( expr.span.shrink_to_hi(), @@ -752,7 +762,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { debug!("suggest_missing_return_type: expected type {:?}", ty); let bound_vars = self.tcx.late_bound_vars(fn_id); let ty = Binder::bind_with_vars(ty, bound_vars); - let ty = self.normalize_associated_types_in(span, ty); + let ty = self.normalize(span, ty); let ty = self.tcx.erase_late_bound_regions(ty); if self.can_coerce(expected, ty) { err.subdiagnostic(ExpectedReturnTypeLabel::Other { span, expected }); @@ -913,22 +923,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { let ty = <dyn AstConv<'_>>::ast_ty_to_ty(self, ty); let bound_vars = self.tcx.late_bound_vars(fn_id); let ty = self.tcx.erase_late_bound_regions(Binder::bind_with_vars(ty, bound_vars)); - let ty = self.normalize_associated_types_in(expr.span, ty); let ty = match self.tcx.asyncness(fn_id.owner) { - hir::IsAsync::Async => { - let infcx = self.tcx.infer_ctxt().build(); - infcx - .get_impl_future_output_ty(ty) - .unwrap_or_else(|| { - span_bug!( - fn_decl.output.span(), - "failed to get output type of async function" - ) - }) - .skip_binder() - } + hir::IsAsync::Async => self.get_impl_future_output_ty(ty).unwrap_or_else(|| { + span_bug!(fn_decl.output.span(), "failed to get output type of async function") + }), hir::IsAsync::NotAsync => ty, }; + let ty = self.normalize(expr.span, ty); if self.can_coerce(found, ty) { err.multipart_suggestion( "you might have meant to return this value", @@ -1082,14 +1083,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { if let Some(into_def_id) = self.tcx.get_diagnostic_item(sym::Into) && self.predicate_must_hold_modulo_regions(&traits::Obligation::new( + self.tcx, self.misc(expr.span), self.param_env, - ty::Binder::dummy(ty::TraitRef { - def_id: into_def_id, - substs: self.tcx.mk_substs_trait(expr_ty, &[expected_ty.into()]), - }) - .to_poly_trait_predicate() - .to_predicate(self.tcx), + ty::Binder::dummy(self.tcx.mk_trait_ref( + into_def_id, + [expr_ty, expected_ty] + )), )) { let sugg = if expr.precedence().order() >= PREC_POSTFIX { @@ -1108,6 +1108,53 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { false } + /// When expecting a `bool` and finding an `Option`, suggests using `let Some(..)` or `.is_some()` + pub(crate) fn suggest_option_to_bool( + &self, + diag: &mut Diagnostic, + expr: &hir::Expr<'_>, + expr_ty: Ty<'tcx>, + expected_ty: Ty<'tcx>, + ) -> bool { + if !expected_ty.is_bool() { + return false; + } + + let ty::Adt(def, _) = expr_ty.peel_refs().kind() else { return false; }; + if !self.tcx.is_diagnostic_item(sym::Option, def.did()) { + return false; + } + + let hir = self.tcx.hir(); + let cond_parent = hir.parent_iter(expr.hir_id).skip_while(|(_, node)| { + matches!(node, hir::Node::Expr(hir::Expr { kind: hir::ExprKind::Binary(op, _, _), .. }) if op.node == hir::BinOpKind::And) + }).next(); + // Don't suggest: + // `let Some(_) = a.is_some() && b` + // ++++++++++ + // since the user probably just misunderstood how `let else` + // and `&&` work together. + if let Some((_, hir::Node::Local(local))) = cond_parent + && let hir::PatKind::Path(qpath) | hir::PatKind::TupleStruct(qpath, _, _) = &local.pat.kind + && let hir::QPath::Resolved(None, path) = qpath + && let Some(did) = path.res.opt_def_id() + .and_then(|did| self.tcx.opt_parent(did)) + .and_then(|did| self.tcx.opt_parent(did)) + && self.tcx.is_diagnostic_item(sym::Option, did) + { + return false; + } + + diag.span_suggestion( + expr.span.shrink_to_hi(), + "use `Option::is_some` to test if the `Option` has a value", + ".is_some()", + Applicability::MachineApplicable, + ); + + true + } + /// Suggest wrapping the block in square brackets instead of curly braces /// in case the block was mistaken array syntax, e.g. `{ 1 }` -> `[ 1 ]`. pub(crate) fn suggest_block_to_brackets( @@ -1149,6 +1196,48 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { } } + #[instrument(skip(self, err))] + pub(crate) fn suggest_floating_point_literal( + &self, + err: &mut Diagnostic, + expr: &hir::Expr<'_>, + expected_ty: Ty<'tcx>, + ) -> bool { + if !expected_ty.is_floating_point() { + return false; + } + match expr.kind { + ExprKind::Struct(QPath::LangItem(LangItem::Range, ..), [start, end], _) => { + err.span_suggestion_verbose( + start.span.shrink_to_hi().with_hi(end.span.lo()), + "remove the unnecessary `.` operator for a floating point literal", + '.', + Applicability::MaybeIncorrect, + ); + true + } + ExprKind::Struct(QPath::LangItem(LangItem::RangeFrom, ..), [start], _) => { + err.span_suggestion_verbose( + expr.span.with_lo(start.span.hi()), + "remove the unnecessary `.` operator for a floating point literal", + '.', + Applicability::MaybeIncorrect, + ); + true + } + ExprKind::Struct(QPath::LangItem(LangItem::RangeTo, ..), [end], _) => { + err.span_suggestion_verbose( + expr.span.until(end.span), + "remove the unnecessary `.` operator and add an integer part for a floating point literal", + "0.", + Applicability::MaybeIncorrect, + ); + true + } + _ => false, + } + } + fn is_loop(&self, id: hir::HirId) -> bool { let node = self.tcx.hir().get(id); matches!(node, Node::Expr(Expr { kind: ExprKind::Loop(..), .. })) |