diff --git a/compiler/rustc_middle/src/mir/query.rs b/compiler/rustc_middle/src/mir/query.rs index a80aa6ad3d81e..0edb79fdbc8e8 100644 --- a/compiler/rustc_middle/src/mir/query.rs +++ b/compiler/rustc_middle/src/mir/query.rs @@ -32,7 +32,6 @@ pub enum UnsafetyViolationDetails { UseOfInlineAssembly, InitializingTypeWith, CastOfPointerToInt, - BorrowOfPackedField, UseOfMutableStatic, UseOfExternStatic, DerefOfRawPointer, @@ -64,11 +63,6 @@ impl UnsafetyViolationDetails { CastOfPointerToInt => { ("cast of pointer to int", "casting pointers to integers in constants") } - BorrowOfPackedField => ( - "borrow of packed field", - "fields of packed structs might be misaligned: dereferencing a misaligned pointer \ - or even just creating a misaligned reference is undefined behavior", - ), UseOfMutableStatic => ( "use of mutable static", "mutable statics can be mutated by multiple threads: aliasing violations or data \ diff --git a/compiler/rustc_mir/src/borrow_check/region_infer/mod.rs b/compiler/rustc_mir/src/borrow_check/region_infer/mod.rs index bbd512fd36050..f4d78ac04cb02 100644 --- a/compiler/rustc_mir/src/borrow_check/region_infer/mod.rs +++ b/compiler/rustc_mir/src/borrow_check/region_infer/mod.rs @@ -1241,7 +1241,7 @@ impl<'tcx> RegionInferenceContext<'tcx> { /// it. However, it works pretty well in practice. In particular, /// this is needed to deal with projection outlives bounds like /// - /// ```ignore (internal compiler representation so lifetime syntax is invalid) + /// ```text /// >::Item: '1 /// ``` /// diff --git a/compiler/rustc_mir_build/src/check_unsafety.rs b/compiler/rustc_mir_build/src/check_unsafety.rs index 83288fa541e44..32799cbf4c7dd 100644 --- a/compiler/rustc_mir_build/src/check_unsafety.rs +++ b/compiler/rustc_mir_build/src/check_unsafety.rs @@ -64,38 +64,30 @@ impl<'tcx> UnsafetyVisitor<'tcx> { SafetyContext::UnsafeFn if unsafe_op_in_unsafe_fn_allowed => {} SafetyContext::UnsafeFn => { // unsafe_op_in_unsafe_fn is disallowed - if kind == BorrowOfPackedField { - // FIXME handle borrows of packed fields - } else { - struct_span_err!( - self.tcx.sess, - span, - E0133, - "{} is unsafe and requires unsafe block", - description, - ) - .span_label(span, description) - .note(note) - .emit(); - } + struct_span_err!( + self.tcx.sess, + span, + E0133, + "{} is unsafe and requires unsafe block", + description, + ) + .span_label(span, description) + .note(note) + .emit(); } SafetyContext::Safe => { - if kind == BorrowOfPackedField { - // FIXME handle borrows of packed fields - } else { - let fn_sugg = if unsafe_op_in_unsafe_fn_allowed { " function or" } else { "" }; - struct_span_err!( - self.tcx.sess, - span, - E0133, - "{} is unsafe and requires unsafe{} block", - description, - fn_sugg, - ) - .span_label(span, description) - .note(note) - .emit(); - } + let fn_sugg = if unsafe_op_in_unsafe_fn_allowed { " function or" } else { "" }; + struct_span_err!( + self.tcx.sess, + span, + E0133, + "{} is unsafe and requires unsafe{} block", + description, + fn_sugg, + ) + .span_label(span, description) + .note(note) + .emit(); } } } @@ -203,8 +195,6 @@ enum UnsafeOpKind { #[allow(dead_code)] // FIXME CastOfPointerToInt, #[allow(dead_code)] // FIXME - BorrowOfPackedField, - #[allow(dead_code)] // FIXME UseOfMutableStatic, #[allow(dead_code)] // FIXME UseOfExternStatic, @@ -244,11 +234,6 @@ impl UnsafeOpKind { CastOfPointerToInt => { ("cast of pointer to int", "casting pointers to integers in constants") } - BorrowOfPackedField => ( - "borrow of packed field", - "fields of packed structs might be misaligned: dereferencing a misaligned pointer \ - or even just creating a misaligned reference is undefined behavior", - ), UseOfMutableStatic => ( "use of mutable static", "mutable statics can be mutated by multiple threads: aliasing violations or data \ diff --git a/compiler/rustc_passes/src/lang_items.rs b/compiler/rustc_passes/src/lang_items.rs index cfc18062d53a3..118fcca4508ea 100644 --- a/compiler/rustc_passes/src/lang_items.rs +++ b/compiler/rustc_passes/src/lang_items.rs @@ -13,12 +13,13 @@ use crate::weak_lang_items; use rustc_middle::middle::cstore::ExternCrate; use rustc_middle::ty::TyCtxt; -use rustc_errors::struct_span_err; +use rustc_errors::{pluralize, struct_span_err}; use rustc_hir as hir; use rustc_hir::def_id::DefId; use rustc_hir::itemlikevisit::ItemLikeVisitor; use rustc_hir::lang_items::{extract, ITEM_REFS}; use rustc_hir::{HirId, LangItem, LanguageItems, Target}; +use rustc_span::Span; use rustc_middle::ty::query::Providers; @@ -61,8 +62,7 @@ impl LanguageItemCollector<'tcx> { match ITEM_REFS.get(&value).cloned() { // Known lang item with attribute on correct target. Some((item_index, expected_target)) if actual_target == expected_target => { - let def_id = self.tcx.hir().local_def_id(hir_id); - self.collect_item(item_index, def_id.to_def_id()); + self.collect_item_extended(item_index, hir_id, span); } // Known lang item with attribute on incorrect target. Some((_, expected_target)) => { @@ -180,6 +180,127 @@ impl LanguageItemCollector<'tcx> { self.items.groups[group as usize].push(item_def_id); } } + + // Like collect_item() above, but also checks whether the lang item is declared + // with the right number of generic arguments if it is a trait. + fn collect_item_extended(&mut self, item_index: usize, hir_id: HirId, span: Span) { + let item_def_id = self.tcx.hir().local_def_id(hir_id).to_def_id(); + let lang_item = LangItem::from_u32(item_index as u32).unwrap(); + let name = lang_item.name(); + + self.collect_item(item_index, item_def_id); + + // Now check whether the lang_item has the expected number of generic + // arguments if it is a trait. Generally speaking, binary and indexing + // operations have one (for the RHS/index), unary operations have none, + // and the rest also have none except for the closure traits (one for + // the argument list), generators (one for the resume argument), + // ordering/equality relations (one for the RHS), and various conversion + // traits. + + let expected_num = match lang_item { + // Binary operations + LangItem::Add + | LangItem::Sub + | LangItem::Mul + | LangItem::Div + | LangItem::Rem + | LangItem::BitXor + | LangItem::BitAnd + | LangItem::BitOr + | LangItem::Shl + | LangItem::Shr + | LangItem::AddAssign + | LangItem::SubAssign + | LangItem::MulAssign + | LangItem::DivAssign + | LangItem::RemAssign + | LangItem::BitXorAssign + | LangItem::BitAndAssign + | LangItem::BitOrAssign + | LangItem::ShlAssign + | LangItem::ShrAssign + | LangItem::Index + | LangItem::IndexMut + + // Miscellaneous + | LangItem::Unsize + | LangItem::CoerceUnsized + | LangItem::DispatchFromDyn + | LangItem::Fn + | LangItem::FnMut + | LangItem::FnOnce + | LangItem::Generator + | LangItem::PartialEq + | LangItem::PartialOrd + => Some(1), + + // Unary operations + LangItem::Neg + | LangItem::Not + + // Miscellaneous + | LangItem::Deref + | LangItem::DerefMut + | LangItem::Sized + | LangItem::StructuralPeq + | LangItem::StructuralTeq + | LangItem::Copy + | LangItem::Clone + | LangItem::Sync + | LangItem::DiscriminantKind + | LangItem::PointeeTrait + | LangItem::Freeze + | LangItem::Drop + | LangItem::Receiver + | LangItem::Future + | LangItem::Unpin + | LangItem::Termination + | LangItem::Try + | LangItem::Send + | LangItem::UnwindSafe + | LangItem::RefUnwindSafe + => Some(0), + + // Not a trait + _ => None, + }; + + if let Some(expected_num) = expected_num { + let (actual_num, generics_span) = match self.tcx.hir().get(hir_id) { + hir::Node::Item(hir::Item { + kind: hir::ItemKind::Trait(_, _, generics, ..), + .. + }) => (generics.params.len(), generics.span), + _ => bug!("op/index/deref lang item target is not a trait: {:?}", lang_item), + }; + + if expected_num != actual_num { + // We are issuing E0718 "incorrect target" here, because while the + // item kind of the target is correct, the target is still wrong + // because of the wrong number of generic arguments. + struct_span_err!( + self.tcx.sess, + span, + E0718, + "`{}` language item must be applied to a trait with {} generic argument{}", + name, + expected_num, + pluralize!(expected_num) + ) + .span_label( + generics_span, + format!( + "this trait has {} generic argument{}, not {}", + actual_num, + pluralize!(actual_num), + expected_num + ), + ) + .emit(); + } + } + } } /// Traverses and collects all the lang items in all crates. diff --git a/compiler/rustc_trait_selection/src/opaque_types.rs b/compiler/rustc_trait_selection/src/opaque_types.rs index fb4a8ce687c4d..7e67bc118ec1e 100644 --- a/compiler/rustc_trait_selection/src/opaque_types.rs +++ b/compiler/rustc_trait_selection/src/opaque_types.rs @@ -46,6 +46,7 @@ pub struct OpaqueTypeDecl<'tcx> { /// type Foo = impl Baz; /// fn bar() -> Foo { /// // ^^^ This is the span we are looking for! + /// } /// ``` /// /// In cases where the fn returns `(impl Trait, impl Trait)` or diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs index 6a4d41ffc1ac9..8bbd2da537513 100644 --- a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs +++ b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs @@ -686,17 +686,36 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> { return false; } + // Blacklist traits for which it would be nonsensical to suggest borrowing. + // For instance, immutable references are always Copy, so suggesting to + // borrow would always succeed, but it's probably not what the user wanted. + let blacklist: Vec<_> = + [LangItem::Copy, LangItem::Clone, LangItem::Unpin, LangItem::Sized, LangItem::Send] + .iter() + .filter_map(|lang_item| self.tcx.lang_items().require(*lang_item).ok()) + .collect(); + let span = obligation.cause.span; let param_env = obligation.param_env; let trait_ref = trait_ref.skip_binder(); - if let ObligationCauseCode::ImplDerivedObligation(obligation) = &obligation.cause.code { - // Try to apply the original trait binding obligation by borrowing. - let self_ty = trait_ref.self_ty(); - let found = self_ty.to_string(); - let new_self_ty = self.tcx.mk_imm_ref(self.tcx.lifetimes.re_static, self_ty); - let substs = self.tcx.mk_substs_trait(new_self_ty, &[]); - let new_trait_ref = ty::TraitRef::new(obligation.parent_trait_ref.def_id(), substs); + let found_ty = trait_ref.self_ty(); + let found_ty_str = found_ty.to_string(); + let imm_borrowed_found_ty = self.tcx.mk_imm_ref(self.tcx.lifetimes.re_static, found_ty); + let imm_substs = self.tcx.mk_substs_trait(imm_borrowed_found_ty, &[]); + let mut_borrowed_found_ty = self.tcx.mk_mut_ref(self.tcx.lifetimes.re_static, found_ty); + let mut_substs = self.tcx.mk_substs_trait(mut_borrowed_found_ty, &[]); + + // Try to apply the original trait binding obligation by borrowing. + let mut try_borrowing = |new_trait_ref: ty::TraitRef<'tcx>, + expected_trait_ref: ty::TraitRef<'tcx>, + mtbl: bool, + blacklist: &[DefId]| + -> bool { + if blacklist.contains(&expected_trait_ref.def_id) { + return false; + } + let new_obligation = Obligation::new( ObligationCause::dummy(), param_env, @@ -713,8 +732,8 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> { let msg = format!( "the trait bound `{}: {}` is not satisfied", - found, - obligation.parent_trait_ref.skip_binder().print_only_trait_path(), + found_ty_str, + expected_trait_ref.print_only_trait_path(), ); if has_custom_message { err.note(&msg); @@ -730,7 +749,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> { span, &format!( "expected an implementor of trait `{}`", - obligation.parent_trait_ref.skip_binder().print_only_trait_path(), + expected_trait_ref.print_only_trait_path(), ), ); @@ -745,16 +764,52 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> { err.span_suggestion( span, - "consider borrowing here", - format!("&{}", snippet), + &format!( + "consider{} borrowing here", + if mtbl { " mutably" } else { "" } + ), + format!("&{}{}", if mtbl { "mut " } else { "" }, snippet), Applicability::MaybeIncorrect, ); } return true; } } + return false; + }; + + if let ObligationCauseCode::ImplDerivedObligation(obligation) = &obligation.cause.code { + let expected_trait_ref = obligation.parent_trait_ref.skip_binder(); + let new_imm_trait_ref = + ty::TraitRef::new(obligation.parent_trait_ref.def_id(), imm_substs); + let new_mut_trait_ref = + ty::TraitRef::new(obligation.parent_trait_ref.def_id(), mut_substs); + if try_borrowing(new_imm_trait_ref, expected_trait_ref, false, &[]) { + return true; + } else { + return try_borrowing(new_mut_trait_ref, expected_trait_ref, true, &[]); + } + } else if let ObligationCauseCode::BindingObligation(_, _) + | ObligationCauseCode::ItemObligation(_) = &obligation.cause.code + { + if try_borrowing( + ty::TraitRef::new(trait_ref.def_id, imm_substs), + trait_ref, + false, + &blacklist[..], + ) { + return true; + } else { + return try_borrowing( + ty::TraitRef::new(trait_ref.def_id, mut_substs), + trait_ref, + true, + &blacklist[..], + ); + } + } else { + false } - false } /// Whenever references are used by mistake, like `for (i, e) in &vec.iter().enumerate()`, diff --git a/compiler/rustc_typeck/src/check/generator_interior.rs b/compiler/rustc_typeck/src/check/generator_interior.rs index e40aa91485858..5f26e701c0ab7 100644 --- a/compiler/rustc_typeck/src/check/generator_interior.rs +++ b/compiler/rustc_typeck/src/check/generator_interior.rs @@ -89,19 +89,31 @@ impl<'a, 'tcx> InteriorVisitor<'a, 'tcx> { if let Some((unresolved_type, unresolved_type_span)) = self.fcx.unresolved_type_vars(&ty) { - let note = format!( - "the type is part of the {} because of this {}", - self.kind, yield_data.source - ); - // If unresolved type isn't a ty_var then unresolved_type_span is None let span = self .prev_unresolved_span .unwrap_or_else(|| unresolved_type_span.unwrap_or(source_span)); - self.fcx - .need_type_info_err_in_generator(self.kind, span, unresolved_type) - .span_note(yield_data.span, &*note) - .emit(); + + // If we encounter an int/float variable, then inference fallback didn't + // finish due to some other error. Don't emit spurious additional errors. + if let ty::Infer(ty::InferTy::IntVar(_) | ty::InferTy::FloatVar(_)) = + unresolved_type.kind() + { + self.fcx + .tcx + .sess + .delay_span_bug(span, &format!("Encountered var {:?}", unresolved_type)); + } else { + let note = format!( + "the type is part of the {} because of this {}", + self.kind, yield_data.source + ); + + self.fcx + .need_type_info_err_in_generator(self.kind, span, unresolved_type) + .span_note(yield_data.span, &*note) + .emit(); + } } else { // Insert the type into the ordered set. let scope_span = scope.map(|s| s.span(self.fcx.tcx, self.region_scope_tree)); diff --git a/compiler/rustc_typeck/src/check/method/mod.rs b/compiler/rustc_typeck/src/check/method/mod.rs index 0b1129a631249..427102afee103 100644 --- a/compiler/rustc_typeck/src/check/method/mod.rs +++ b/compiler/rustc_typeck/src/check/method/mod.rs @@ -303,8 +303,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { opt_input_types: Option<&[Ty<'tcx>]>, ) -> Option>> { debug!( - "lookup_in_trait_adjusted(self_ty={:?}, m_name={}, trait_def_id={:?})", - self_ty, m_name, trait_def_id + "lookup_in_trait_adjusted(self_ty={:?}, m_name={}, trait_def_id={:?}, opt_input_types={:?})", + self_ty, m_name, trait_def_id, opt_input_types ); // Construct a trait-reference `self_ty : Trait` diff --git a/compiler/rustc_typeck/src/check/mod.rs b/compiler/rustc_typeck/src/check/mod.rs index d6db2e1d76f89..ad7853b7cd0f1 100644 --- a/compiler/rustc_typeck/src/check/mod.rs +++ b/compiler/rustc_typeck/src/check/mod.rs @@ -1187,3 +1187,14 @@ fn fatally_break_rust(sess: &Session) { fn potentially_plural_count(count: usize, word: &str) -> String { format!("{} {}{}", count, word, pluralize!(count)) } + +fn has_expected_num_generic_args<'tcx>( + tcx: TyCtxt<'tcx>, + trait_did: Option, + expected: usize, +) -> bool { + trait_did.map_or(true, |trait_did| { + let generics = tcx.generics_of(trait_did); + generics.count() == expected + if generics.has_self { 1 } else { 0 } + }) +} diff --git a/compiler/rustc_typeck/src/check/op.rs b/compiler/rustc_typeck/src/check/op.rs index 567cb1a90d0d9..963436d05d8ef 100644 --- a/compiler/rustc_typeck/src/check/op.rs +++ b/compiler/rustc_typeck/src/check/op.rs @@ -1,7 +1,7 @@ //! Code related to processing overloaded binary and unary operators. use super::method::MethodCallee; -use super::FnCtxt; +use super::{has_expected_num_generic_args, FnCtxt}; use rustc_ast as ast; use rustc_errors::{self, struct_span_err, Applicability, DiagnosticBuilder}; use rustc_hir as hir; @@ -795,6 +795,23 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { lhs_ty, op, opname, trait_did ); + // Catches cases like #83893, where a lang item is declared with the + // wrong number of generic arguments. Should have yielded an error + // elsewhere by now, but we have to catch it here so that we do not + // index `other_tys` out of bounds (if the lang item has too many + // generic arguments, `other_tys` is too short). + if !has_expected_num_generic_args( + self.tcx, + trait_did, + match op { + // Binary ops have a generic right-hand side, unary ops don't + Op::Binary(..) => 1, + Op::Unary(..) => 0, + }, + ) { + return Err(()); + } + let method = trait_did.and_then(|trait_did| { let opname = Ident::with_dummy_span(opname); self.lookup_method_in_trait(span, opname, trait_did, lhs_ty, Some(other_tys)) diff --git a/compiler/rustc_typeck/src/check/place_op.rs b/compiler/rustc_typeck/src/check/place_op.rs index 5bd385107ca39..a63aec07ad1c0 100644 --- a/compiler/rustc_typeck/src/check/place_op.rs +++ b/compiler/rustc_typeck/src/check/place_op.rs @@ -1,5 +1,5 @@ use crate::check::method::MethodCallee; -use crate::check::{FnCtxt, PlaceOp}; +use crate::check::{has_expected_num_generic_args, FnCtxt, PlaceOp}; use rustc_hir as hir; use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind}; use rustc_infer::infer::InferOk; @@ -153,6 +153,21 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { PlaceOp::Deref => (self.tcx.lang_items().deref_trait(), sym::deref), PlaceOp::Index => (self.tcx.lang_items().index_trait(), sym::index), }; + + // If the lang item was declared incorrectly, stop here so that we don't + // run into an ICE (#83893). The error is reported where the lang item is + // declared. + if !has_expected_num_generic_args( + self.tcx, + imm_tr, + match op { + PlaceOp::Deref => 0, + PlaceOp::Index => 1, + }, + ) { + return None; + } + imm_tr.and_then(|trait_did| { self.lookup_method_in_trait( span, @@ -177,6 +192,21 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { PlaceOp::Deref => (self.tcx.lang_items().deref_mut_trait(), sym::deref_mut), PlaceOp::Index => (self.tcx.lang_items().index_mut_trait(), sym::index_mut), }; + + // If the lang item was declared incorrectly, stop here so that we don't + // run into an ICE (#83893). The error is reported where the lang item is + // declared. + if !has_expected_num_generic_args( + self.tcx, + mut_tr, + match op { + PlaceOp::Deref => 0, + PlaceOp::Index => 1, + }, + ) { + return None; + } + mut_tr.and_then(|trait_did| { self.lookup_method_in_trait( span, diff --git a/compiler/rustc_typeck/src/check/upvar.rs b/compiler/rustc_typeck/src/check/upvar.rs index ff506ef8727b9..71e222c560a05 100644 --- a/compiler/rustc_typeck/src/check/upvar.rs +++ b/compiler/rustc_typeck/src/check/upvar.rs @@ -323,7 +323,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { /// /// InferBorrowKind results in a structure like this: /// - /// ``` + /// ```text /// { /// Place(base: hir_id_s, projections: [], ....) -> { /// capture_kind_expr: hir_id_L5, @@ -348,7 +348,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { /// ``` /// /// After the min capture analysis, we get: - /// ``` + /// ```text /// { /// hir_id_s -> [ /// Place(base: hir_id_s, projections: [], ....) -> { diff --git a/library/core/src/iter/sources/repeat.rs b/library/core/src/iter/sources/repeat.rs index d1f2879235f1a..a9478041c69c4 100644 --- a/library/core/src/iter/sources/repeat.rs +++ b/library/core/src/iter/sources/repeat.rs @@ -72,10 +72,32 @@ impl Iterator for Repeat { fn next(&mut self) -> Option { Some(self.element.clone()) } + #[inline] fn size_hint(&self) -> (usize, Option) { (usize::MAX, None) } + + #[inline] + fn advance_by(&mut self, n: usize) -> Result<(), usize> { + // Advancing an infinite iterator of a single element is a no-op. + let _ = n; + Ok(()) + } + + #[inline] + fn nth(&mut self, n: usize) -> Option { + let _ = n; + Some(self.element.clone()) + } + + fn last(self) -> Option { + loop {} + } + + fn count(self) -> usize { + loop {} + } } #[stable(feature = "rust1", since = "1.0.0")] @@ -84,6 +106,19 @@ impl DoubleEndedIterator for Repeat { fn next_back(&mut self) -> Option { Some(self.element.clone()) } + + #[inline] + fn advance_back_by(&mut self, n: usize) -> Result<(), usize> { + // Advancing an infinite iterator of a single element is a no-op. + let _ = n; + Ok(()) + } + + #[inline] + fn nth_back(&mut self, n: usize) -> Option { + let _ = n; + Some(self.element.clone()) + } } #[stable(feature = "fused", since = "1.26.0")] diff --git a/src/doc/rustdoc/src/lints.md b/src/doc/rustdoc/src/lints.md index a6626679a7d60..16b091eb255b0 100644 --- a/src/doc/rustdoc/src/lints.md +++ b/src/doc/rustdoc/src/lints.md @@ -294,6 +294,50 @@ warning: unclosed HTML tag `h1` warning: 2 warnings emitted ``` +## invalid_rust_codeblocks + +This lint **warns by default**. It detects Rust code blocks in documentation +examples that are invalid (e.g. empty, not parsable as Rust). For example: + +```rust +/// Empty code blocks (with and without the `rust` marker): +/// +/// ```rust +/// ``` +/// +/// Invalid syntax in code blocks: +/// +/// ```rust +/// '< +/// ``` +pub fn foo() {} +``` + +Which will give: + +```text +warning: Rust code block is empty + --> lint.rs:3:5 + | +3 | /// ```rust + | _____^ +4 | | /// ``` + | |_______^ + | + = note: `#[warn(rustdoc::invalid_rust_codeblocks)]` on by default + +warning: could not parse code block as Rust code + --> lint.rs:8:5 + | +8 | /// ```rust + | _____^ +9 | | /// '< +10 | | /// ``` + | |_______^ + | + = note: error from rustc: unterminated character literal +``` + ## bare_urls This lint is **warn-by-default**. It detects URLs which are not links. diff --git a/src/librustdoc/html/render/mod.rs b/src/librustdoc/html/render/mod.rs index b807c5ccc4759..a288b43722ad4 100644 --- a/src/librustdoc/html/render/mod.rs +++ b/src/librustdoc/html/render/mod.rs @@ -509,7 +509,11 @@ fn document(w: &mut Buffer, cx: &Context<'_>, item: &clean::Item, parent: Option info!("Documenting {}", name); } document_item_info(w, cx, item, parent); - document_full_collapsible(w, item, cx); + if parent.is_none() { + document_full_collapsible(w, item, cx); + } else { + document_full(w, item, cx); + } } /// Render md_text as markdown. diff --git a/src/librustdoc/html/render/print_item.rs b/src/librustdoc/html/render/print_item.rs index ff639cb292462..bac9c21f0f39b 100644 --- a/src/librustdoc/html/render/print_item.rs +++ b/src/librustdoc/html/render/print_item.rs @@ -578,12 +578,13 @@ fn item_trait(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item, t: &clean::Tra info!("Documenting {} on {:?}", name, t.name); let item_type = m.type_(); let id = cx.derive_id(format!("{}.{}", item_type, name)); + write!(w, "
"); write!(w, "

", id = id,); render_assoc_item(w, m, AssocItemLink::Anchor(Some(&id)), ItemType::Impl, cx); w.write_str(""); render_stability_since(w, m, t, cx.tcx()); write_srclink(cx, m, w); - w.write_str("

"); + w.write_str(""); document(w, cx, m, Some(t)); } diff --git a/src/librustdoc/lint.rs b/src/librustdoc/lint.rs index 1b79811d4b075..376c83b1a6ea8 100644 --- a/src/librustdoc/lint.rs +++ b/src/librustdoc/lint.rs @@ -157,6 +157,18 @@ declare_rustdoc_lint! { "detects URLs that are not hyperlinks" } +declare_rustdoc_lint! { + /// The `invalid_rust_codeblocks` lint detects Rust code blocks in + /// documentation examples that are invalid (e.g. empty, not parsable as + /// Rust code). This is a `rustdoc` only lint, see the documentation in the + /// [rustdoc book]. + /// + /// [rustdoc book]: ../../../rustdoc/lints.html#invalid_rust_codeblocks + INVALID_RUST_CODEBLOCKS, + Warn, + "codeblock could not be parsed as valid Rust or is empty" +} + crate static RUSTDOC_LINTS: Lazy> = Lazy::new(|| { vec![ BROKEN_INTRA_DOC_LINKS, @@ -164,6 +176,7 @@ crate static RUSTDOC_LINTS: Lazy> = Lazy::new(|| { MISSING_DOC_CODE_EXAMPLES, PRIVATE_DOC_TESTS, INVALID_CODEBLOCK_ATTRIBUTES, + INVALID_RUST_CODEBLOCKS, INVALID_HTML_TAGS, BARE_URLS, MISSING_CRATE_LEVEL_DOCS, diff --git a/src/librustdoc/passes/check_code_block_syntax.rs b/src/librustdoc/passes/check_code_block_syntax.rs index 8d07cde51880c..7ccfdf29041d2 100644 --- a/src/librustdoc/passes/check_code_block_syntax.rs +++ b/src/librustdoc/passes/check_code_block_syntax.rs @@ -1,5 +1,6 @@ use rustc_data_structures::sync::{Lock, Lrc}; use rustc_errors::{emitter::Emitter, Applicability, Diagnostic, Handler}; +use rustc_middle::lint::LintDiagnosticBuilder; use rustc_parse::parse_stream_from_source_str; use rustc_session::parse::ParseSess; use rustc_span::source_map::{FilePathMapping, SourceMap}; @@ -47,55 +48,68 @@ impl<'a, 'tcx> SyntaxChecker<'a, 'tcx> { .unwrap_or(false); let buffer = buffer.borrow(); - if buffer.has_errors || is_empty { - let mut diag = if let Some(sp) = super::source_span_for_markdown_range( - self.cx.tcx, - &dox, - &code_block.range, - &item.attrs, - ) { - let (warning_message, suggest_using_text) = if buffer.has_errors { - ("could not parse code block as Rust code", true) - } else { - ("Rust code block is empty", false) - }; - - let mut diag = self.cx.sess().struct_span_warn(sp, warning_message); - - if code_block.syntax.is_none() && code_block.is_fenced { - let sp = sp.from_inner(InnerSpan::new(0, 3)); - diag.span_suggestion( - sp, - "mark blocks that do not contain Rust code as text", - String::from("```text"), - Applicability::MachineApplicable, + if !buffer.has_errors && !is_empty { + // No errors in a non-empty program. + return; + } + + let local_id = match item.def_id.as_real().and_then(|x| x.as_local()) { + Some(id) => id, + // We don't need to check the syntax for other crates so returning + // without doing anything should not be a problem. + None => return, + }; + + let hir_id = self.cx.tcx.hir().local_def_id_to_hir_id(local_id); + let empty_block = code_block.syntax.is_none() && code_block.is_fenced; + let is_ignore = code_block.is_ignore; + + // The span and whether it is precise or not. + let (sp, precise_span) = match super::source_span_for_markdown_range( + self.cx.tcx, + &dox, + &code_block.range, + &item.attrs, + ) { + Some(sp) => (sp, true), + None => (item.attr_span(self.cx.tcx), false), + }; + + // lambda that will use the lint to start a new diagnostic and add + // a suggestion to it when needed. + let diag_builder = |lint: LintDiagnosticBuilder<'_>| { + let explanation = if is_ignore { + "`ignore` code blocks require valid Rust code for syntax highlighting; \ + mark blocks that do not contain Rust code as text" + } else { + "mark blocks that do not contain Rust code as text" + }; + let msg = if buffer.has_errors { + "could not parse code block as Rust code" + } else { + "Rust code block is empty" + }; + let mut diag = lint.build(msg); + + if precise_span { + if is_ignore { + // giving an accurate suggestion is hard because `ignore` might not have come first in the list. + // just give a `help` instead. + diag.span_help( + sp.from_inner(InnerSpan::new(0, 3)), + &format!("{}: ```text", explanation), ); - } else if suggest_using_text && code_block.is_ignore { - let sp = sp.from_inner(InnerSpan::new(0, 3)); + } else if empty_block { diag.span_suggestion( - sp, - "`ignore` code blocks require valid Rust code for syntax highlighting. \ - Mark blocks that do not contain Rust code as text", - String::from("```text,"), + sp.from_inner(InnerSpan::new(0, 3)), + explanation, + String::from("```text"), Applicability::MachineApplicable, ); } - - diag - } else { - // We couldn't calculate the span of the markdown block that had the error, so our - // diagnostics are going to be a bit lacking. - let mut diag = self.cx.sess().struct_span_warn( - item.attr_span(self.cx.tcx), - "doc comment contains an invalid Rust code block", - ); - - if code_block.syntax.is_none() && code_block.is_fenced { - diag.help("mark blocks that do not contain Rust code as text: ```text"); - } - - diag - }; + } else if empty_block || is_ignore { + diag.help(&format!("{}: ```text", explanation)); + } // FIXME(#67563): Provide more context for these errors by displaying the spans inline. for message in buffer.messages.iter() { @@ -103,7 +117,17 @@ impl<'a, 'tcx> SyntaxChecker<'a, 'tcx> { } diag.emit(); - } + }; + + // Finally build and emit the completed diagnostic. + // All points of divergence have been handled earlier so this can be + // done the same way whether the span is precise or not. + self.cx.tcx.struct_span_lint_hir( + crate::lint::INVALID_RUST_CODEBLOCKS, + hir_id, + sp, + diag_builder, + ); } } diff --git a/src/test/rustdoc-ui/ignore-block-help.rs b/src/test/rustdoc-ui/ignore-block-help.rs index c22dddd11dffa..86f6a2868fb56 100644 --- a/src/test/rustdoc-ui/ignore-block-help.rs +++ b/src/test/rustdoc-ui/ignore-block-help.rs @@ -3,5 +3,8 @@ /// ```ignore (to-prevent-tidy-error) /// let heart = '❤️'; /// ``` -//~^^^ WARN +//~^^^ WARNING could not parse code block +//~| NOTE on by default +//~| NOTE character literal may only contain one codepoint +//~| HELP `ignore` code blocks require valid Rust code pub struct X; diff --git a/src/test/rustdoc-ui/ignore-block-help.stderr b/src/test/rustdoc-ui/ignore-block-help.stderr index d45cd92d2d106..9c02ff11d19c4 100644 --- a/src/test/rustdoc-ui/ignore-block-help.stderr +++ b/src/test/rustdoc-ui/ignore-block-help.stderr @@ -7,11 +7,13 @@ LL | | /// let heart = '❤️'; LL | | /// ``` | |_______^ | - = note: error from rustc: character literal may only contain one codepoint -help: `ignore` code blocks require valid Rust code for syntax highlighting. Mark blocks that do not contain Rust code as text + = note: `#[warn(rustdoc::invalid_rust_codeblocks)]` on by default +help: `ignore` code blocks require valid Rust code for syntax highlighting; mark blocks that do not contain Rust code as text: ```text + --> $DIR/ignore-block-help.rs:3:5 | -LL | /// ```text,ignore (to-prevent-tidy-error) - | ^^^^^^^^ +LL | /// ```ignore (to-prevent-tidy-error) + | ^^^ + = note: error from rustc: character literal may only contain one codepoint warning: 1 warning emitted diff --git a/src/test/rustdoc-ui/invalid-syntax.rs b/src/test/rustdoc-ui/invalid-syntax.rs index c395a8ef3d41a..b503d1093fda8 100644 --- a/src/test/rustdoc-ui/invalid-syntax.rs +++ b/src/test/rustdoc-ui/invalid-syntax.rs @@ -71,7 +71,7 @@ pub fn blargh() {} /// \_ #[doc = "```"] pub fn crazy_attrs() {} -//~^^^^ WARNING doc comment contains an invalid Rust code block +//~^^^^ WARNING could not parse code block /// ```rust /// ``` diff --git a/src/test/rustdoc-ui/invalid-syntax.stderr b/src/test/rustdoc-ui/invalid-syntax.stderr index 75acdc5ab5f26..82eac9bd68b21 100644 --- a/src/test/rustdoc-ui/invalid-syntax.stderr +++ b/src/test/rustdoc-ui/invalid-syntax.stderr @@ -7,6 +7,7 @@ LL | | /// \__________pkt->size___________/ \_result->size_/ \__pkt->si LL | | /// ``` | |_______^ | + = note: `#[warn(rustdoc::invalid_rust_codeblocks)]` on by default = note: error from rustc: unknown start of token: \ = note: error from rustc: unknown start of token: \ = note: error from rustc: unknown start of token: \ @@ -90,7 +91,7 @@ LL | | /// ``` | = note: error from rustc: unknown start of token: \ -warning: doc comment contains an invalid Rust code block +warning: could not parse code block as Rust code --> $DIR/invalid-syntax.rs:70:1 | LL | / #[doc = "```"] diff --git a/src/test/rustdoc/toggle-trait-fn.rs b/src/test/rustdoc/toggle-trait-fn.rs new file mode 100644 index 0000000000000..a160809cbf957 --- /dev/null +++ b/src/test/rustdoc/toggle-trait-fn.rs @@ -0,0 +1,7 @@ +#![crate_name = "foo"] + +// @has foo/trait.Foo.html +// @has - '//details[@class="rustdoc-toggle"]//code' 'bar' +pub trait Foo { + fn bar() -> (); +} diff --git a/src/test/ui/async-await/issue-73741-type-err.rs b/src/test/ui/async-await/issue-73741-type-err.rs new file mode 100644 index 0000000000000..c5b9e34edf703 --- /dev/null +++ b/src/test/ui/async-await/issue-73741-type-err.rs @@ -0,0 +1,14 @@ +// edition:2018 +// +// Regression test for issue #73741 +// Ensures that we don't emit spurious errors when +// a type error ocurrs in an `async fn` + +async fn weird() { + 1 = 2; //~ ERROR invalid left-hand side + + let mut loop_count = 0; + async {}.await +} + +fn main() {} diff --git a/src/test/ui/async-await/issue-73741-type-err.stderr b/src/test/ui/async-await/issue-73741-type-err.stderr new file mode 100644 index 0000000000000..0b5343a98cfb4 --- /dev/null +++ b/src/test/ui/async-await/issue-73741-type-err.stderr @@ -0,0 +1,11 @@ +error[E0070]: invalid left-hand side of assignment + --> $DIR/issue-73741-type-err.rs:8:7 + | +LL | 1 = 2; + | - ^ + | | + | cannot assign to this expression + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0070`. diff --git a/src/test/ui/lang-item-missing-generator.rs b/src/test/ui/lang-items/lang-item-missing-generator.rs similarity index 100% rename from src/test/ui/lang-item-missing-generator.rs rename to src/test/ui/lang-items/lang-item-missing-generator.rs diff --git a/src/test/ui/lang-item-missing-generator.stderr b/src/test/ui/lang-items/lang-item-missing-generator.stderr similarity index 100% rename from src/test/ui/lang-item-missing-generator.stderr rename to src/test/ui/lang-items/lang-item-missing-generator.stderr diff --git a/src/test/ui/lang-item-missing.rs b/src/test/ui/lang-items/lang-item-missing.rs similarity index 100% rename from src/test/ui/lang-item-missing.rs rename to src/test/ui/lang-items/lang-item-missing.rs diff --git a/src/test/ui/lang-item-missing.stderr b/src/test/ui/lang-items/lang-item-missing.stderr similarity index 100% rename from src/test/ui/lang-item-missing.stderr rename to src/test/ui/lang-items/lang-item-missing.stderr diff --git a/src/test/ui/lang-items/wrong-number-generic-args-add.rs b/src/test/ui/lang-items/wrong-number-generic-args-add.rs new file mode 100644 index 0000000000000..9f4f2464a1e65 --- /dev/null +++ b/src/test/ui/lang-items/wrong-number-generic-args-add.rs @@ -0,0 +1,20 @@ +// Checks whether declaring a lang item with the wrong number +// of generic arguments crashes the compiler (issue #83893). + +#![feature(lang_items,no_core)] +#![no_core] +#![crate_type="lib"] + +#[lang = "sized"] +trait MySized {} + +#[lang = "add"] +trait MyAdd<'a, T> {} +//~^^ ERROR: `add` language item must be applied to a trait with 1 generic argument [E0718] + +fn ice() { + let r = 5; + let a = 6; + r + a + //~^ ERROR: cannot add `{integer}` to `{integer}` [E0369] +} diff --git a/src/test/ui/lang-items/wrong-number-generic-args-add.stderr b/src/test/ui/lang-items/wrong-number-generic-args-add.stderr new file mode 100644 index 0000000000000..6f89441fd285d --- /dev/null +++ b/src/test/ui/lang-items/wrong-number-generic-args-add.stderr @@ -0,0 +1,20 @@ +error[E0718]: `add` language item must be applied to a trait with 1 generic argument + --> $DIR/wrong-number-generic-args-add.rs:11:1 + | +LL | #[lang = "add"] + | ^^^^^^^^^^^^^^^ +LL | trait MyAdd<'a, T> {} + | ------- this trait has 2 generic arguments, not 1 + +error[E0369]: cannot add `{integer}` to `{integer}` + --> $DIR/wrong-number-generic-args-add.rs:18:7 + | +LL | r + a + | - ^ - {integer} + | | + | {integer} + +error: aborting due to 2 previous errors + +Some errors have detailed explanations: E0369, E0718. +For more information about an error, try `rustc --explain E0369`. diff --git a/src/test/ui/lang-items/wrong-number-generic-args-index.rs b/src/test/ui/lang-items/wrong-number-generic-args-index.rs new file mode 100644 index 0000000000000..1d90e63dc5470 --- /dev/null +++ b/src/test/ui/lang-items/wrong-number-generic-args-index.rs @@ -0,0 +1,19 @@ +// Checks whether declaring a lang item with the wrong number +// of generic arguments crashes the compiler (issue #83893). + +#![feature(lang_items,no_core)] +#![no_core] +#![crate_type="lib"] + +#[lang = "sized"] +trait MySized {} + +#[lang = "index"] +trait MyIndex<'a, T> {} +//~^^ ERROR: `index` language item must be applied to a trait with 1 generic argument [E0718] + +fn ice() { + let arr = [0; 5]; + let _ = arr[2]; + //~^ ERROR: cannot index into a value of type `[{integer}; 5]` [E0608] +} diff --git a/src/test/ui/lang-items/wrong-number-generic-args-index.stderr b/src/test/ui/lang-items/wrong-number-generic-args-index.stderr new file mode 100644 index 0000000000000..bc3f19ff27623 --- /dev/null +++ b/src/test/ui/lang-items/wrong-number-generic-args-index.stderr @@ -0,0 +1,18 @@ +error[E0718]: `index` language item must be applied to a trait with 1 generic argument + --> $DIR/wrong-number-generic-args-index.rs:11:1 + | +LL | #[lang = "index"] + | ^^^^^^^^^^^^^^^^^ +LL | trait MyIndex<'a, T> {} + | ------- this trait has 2 generic arguments, not 1 + +error[E0608]: cannot index into a value of type `[{integer}; 5]` + --> $DIR/wrong-number-generic-args-index.rs:17:13 + | +LL | let _ = arr[2]; + | ^^^^^^ + +error: aborting due to 2 previous errors + +Some errors have detailed explanations: E0608, E0718. +For more information about an error, try `rustc --explain E0608`. diff --git a/src/test/ui/suggestions/imm-ref-trait-object-literal.stderr b/src/test/ui/suggestions/imm-ref-trait-object-literal.stderr index df483b3912d69..bd060c92cd469 100644 --- a/src/test/ui/suggestions/imm-ref-trait-object-literal.stderr +++ b/src/test/ui/suggestions/imm-ref-trait-object-literal.stderr @@ -21,10 +21,10 @@ LL | fn foo(_: X) {} | ----- required by this bound in `foo` ... LL | foo(s); - | ^ the trait `Trait` is not implemented for `S` - | - = help: the following implementations were found: - <&'a mut S as Trait> + | ^ + | | + | expected an implementor of trait `Trait` + | help: consider mutably borrowing here: `&mut s` error: aborting due to 2 previous errors diff --git a/src/test/ui/suggestions/issue-84973-2.rs b/src/test/ui/suggestions/issue-84973-2.rs new file mode 100644 index 0000000000000..050cf8c64b361 --- /dev/null +++ b/src/test/ui/suggestions/issue-84973-2.rs @@ -0,0 +1,13 @@ +// A slight variation of issue-84973.rs. Here, a mutable borrow is +// required (and the obligation kind is different). + +trait Tr {} +impl Tr for &mut i32 {} + +fn foo(i: T) {} + +fn main() { + let a: i32 = 32; + foo(a); + //~^ ERROR: the trait bound `i32: Tr` is not satisfied [E0277] +} diff --git a/src/test/ui/suggestions/issue-84973-2.stderr b/src/test/ui/suggestions/issue-84973-2.stderr new file mode 100644 index 0000000000000..b6ed437b5eefd --- /dev/null +++ b/src/test/ui/suggestions/issue-84973-2.stderr @@ -0,0 +1,15 @@ +error[E0277]: the trait bound `i32: Tr` is not satisfied + --> $DIR/issue-84973-2.rs:11:9 + | +LL | fn foo(i: T) {} + | -- required by this bound in `foo` +... +LL | foo(a); + | ^ + | | + | expected an implementor of trait `Tr` + | help: consider mutably borrowing here: `&mut a` + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0277`. diff --git a/src/test/ui/suggestions/issue-84973-blacklist.rs b/src/test/ui/suggestions/issue-84973-blacklist.rs new file mode 100644 index 0000000000000..db954530b1beb --- /dev/null +++ b/src/test/ui/suggestions/issue-84973-blacklist.rs @@ -0,0 +1,29 @@ +// Checks that certain traits for which we don't want to suggest borrowing +// are blacklisted and don't cause the suggestion to be issued. + +#![feature(generators)] + +fn f_copy(t: T) {} +fn f_clone(t: T) {} +fn f_unpin(t: T) {} +fn f_sized(t: T) {} +fn f_send(t: T) {} + +struct S; + +fn main() { + f_copy("".to_string()); //~ ERROR: the trait bound `String: Copy` is not satisfied [E0277] + f_clone(S); //~ ERROR: the trait bound `S: Clone` is not satisfied [E0277] + f_unpin(static || { yield; }); + //~^ ERROR: cannot be unpinned [E0277] + + let cl = || (); + let ref_cl: &dyn Fn() -> () = &cl; + f_sized(*ref_cl); + //~^ ERROR: the size for values of type `dyn Fn()` cannot be known at compilation time [E0277] + //~| ERROR: the size for values of type `dyn Fn()` cannot be known at compilation time [E0277] + + use std::rc::Rc; + let rc = Rc::new(0); + f_send(rc); //~ ERROR: `Rc<{integer}>` cannot be sent between threads safely [E0277] +} diff --git a/src/test/ui/suggestions/issue-84973-blacklist.stderr b/src/test/ui/suggestions/issue-84973-blacklist.stderr new file mode 100644 index 0000000000000..f1e6ef883ae90 --- /dev/null +++ b/src/test/ui/suggestions/issue-84973-blacklist.stderr @@ -0,0 +1,64 @@ +error[E0277]: the trait bound `String: Copy` is not satisfied + --> $DIR/issue-84973-blacklist.rs:15:12 + | +LL | fn f_copy(t: T) {} + | ---- required by this bound in `f_copy` +... +LL | f_copy("".to_string()); + | ^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `String` + +error[E0277]: the trait bound `S: Clone` is not satisfied + --> $DIR/issue-84973-blacklist.rs:16:13 + | +LL | fn f_clone(t: T) {} + | ----- required by this bound in `f_clone` +... +LL | f_clone(S); + | ^ the trait `Clone` is not implemented for `S` + +error[E0277]: `[static generator@$DIR/issue-84973-blacklist.rs:17:13: 17:33]` cannot be unpinned + --> $DIR/issue-84973-blacklist.rs:17:5 + | +LL | fn f_unpin(t: T) {} + | ----- required by this bound in `f_unpin` +... +LL | f_unpin(static || { yield; }); + | ^^^^^^^ the trait `Unpin` is not implemented for `[static generator@$DIR/issue-84973-blacklist.rs:17:13: 17:33]` + | + = note: consider using `Box::pin` + +error[E0277]: the size for values of type `dyn Fn()` cannot be known at compilation time + --> $DIR/issue-84973-blacklist.rs:22:13 + | +LL | fn f_sized(t: T) {} + | - required by this bound in `f_sized` +... +LL | f_sized(*ref_cl); + | ^^^^^^^ doesn't have a size known at compile-time + | + = help: the trait `Sized` is not implemented for `dyn Fn()` + +error[E0277]: `Rc<{integer}>` cannot be sent between threads safely + --> $DIR/issue-84973-blacklist.rs:28:12 + | +LL | fn f_send(t: T) {} + | ---- required by this bound in `f_send` +... +LL | f_send(rc); + | ^^ `Rc<{integer}>` cannot be sent between threads safely + | + = help: the trait `Send` is not implemented for `Rc<{integer}>` + +error[E0277]: the size for values of type `dyn Fn()` cannot be known at compilation time + --> $DIR/issue-84973-blacklist.rs:22:5 + | +LL | f_sized(*ref_cl); + | ^^^^^^^ doesn't have a size known at compile-time + | + = help: the trait `Sized` is not implemented for `dyn Fn()` + = note: all function arguments must have a statically known size + = help: unsized fn params are gated as an unstable feature + +error: aborting due to 6 previous errors + +For more information about this error, try `rustc --explain E0277`. diff --git a/src/test/ui/suggestions/issue-84973-negative.rs b/src/test/ui/suggestions/issue-84973-negative.rs new file mode 100644 index 0000000000000..f339251e57dab --- /dev/null +++ b/src/test/ui/suggestions/issue-84973-negative.rs @@ -0,0 +1,12 @@ +// Checks that we only suggest borrowing if &T actually implements the trait. + +trait Tr {} +impl Tr for &f32 {} +fn bar(t: T) {} + +fn main() { + let a = 0i32; + let b = 0.0f32; + bar(a); //~ ERROR: the trait bound `i32: Tr` is not satisfied [E0277] + bar(b); //~ ERROR: the trait bound `f32: Tr` is not satisfied [E0277] +} diff --git a/src/test/ui/suggestions/issue-84973-negative.stderr b/src/test/ui/suggestions/issue-84973-negative.stderr new file mode 100644 index 0000000000000..94513eca0bf09 --- /dev/null +++ b/src/test/ui/suggestions/issue-84973-negative.stderr @@ -0,0 +1,24 @@ +error[E0277]: the trait bound `i32: Tr` is not satisfied + --> $DIR/issue-84973-negative.rs:10:9 + | +LL | fn bar(t: T) {} + | -- required by this bound in `bar` +... +LL | bar(a); + | ^ the trait `Tr` is not implemented for `i32` + +error[E0277]: the trait bound `f32: Tr` is not satisfied + --> $DIR/issue-84973-negative.rs:11:9 + | +LL | fn bar(t: T) {} + | -- required by this bound in `bar` +... +LL | bar(b); + | ^ + | | + | expected an implementor of trait `Tr` + | help: consider borrowing here: `&b` + +error: aborting due to 2 previous errors + +For more information about this error, try `rustc --explain E0277`. diff --git a/src/test/ui/suggestions/issue-84973.rs b/src/test/ui/suggestions/issue-84973.rs new file mode 100644 index 0000000000000..42468478ed9a2 --- /dev/null +++ b/src/test/ui/suggestions/issue-84973.rs @@ -0,0 +1,33 @@ +// Checks whether borrowing is suggested when a trait bound is not satisfied +// for found type `T`, but is for `&/&mut T`. + +fn main() { + let f = Fancy{}; + let o = Other::new(f); + //~^ ERROR: the trait bound `Fancy: SomeTrait` is not satisfied [E0277] +} + +struct Fancy {} + +impl <'a> SomeTrait for &'a Fancy { +} + +trait SomeTrait {} + +struct Other<'a, G> { + a: &'a str, + g: G, +} + +// Broadly copied from https://docs.rs/petgraph/0.5.1/src/petgraph/dot.rs.html#70 +impl<'a, G> Other<'a, G> +where + G: SomeTrait, +{ + pub fn new(g: G) -> Self { + Other { + a: "hi", + g: g, + } + } +} diff --git a/src/test/ui/suggestions/issue-84973.stderr b/src/test/ui/suggestions/issue-84973.stderr new file mode 100644 index 0000000000000..49fa94da85923 --- /dev/null +++ b/src/test/ui/suggestions/issue-84973.stderr @@ -0,0 +1,15 @@ +error[E0277]: the trait bound `Fancy: SomeTrait` is not satisfied + --> $DIR/issue-84973.rs:6:24 + | +LL | let o = Other::new(f); + | ^ + | | + | expected an implementor of trait `SomeTrait` + | help: consider borrowing here: `&f` +... +LL | pub fn new(g: G) -> Self { + | ------------------------ required by `Other::<'a, G>::new` + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0277`.