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| author | Philipp Krones <hello@philkrones.com> | 2023-09-12 18:13:53 +0200 |
|---|---|---|
| committer | Philipp Krones <hello@philkrones.com> | 2023-09-12 18:44:06 +0200 |
| commit | 471469d30facd25ed3072524694e369aeb72082c (patch) | |
| tree | d4e3a94e2e495518cf5058dd9dd3ceab59083d16 /clippy_lints/src | |
| parent | b643f20f464c93894c9347c8bc34a46caf8355f0 (diff) | |
| download | rust-471469d30facd25ed3072524694e369aeb72082c.tar.gz rust-471469d30facd25ed3072524694e369aeb72082c.zip | |
Merge commit '98363cbf6a7c3f8b571a7d92a3c645bb4376e4a6' into clippyup
Diffstat (limited to 'clippy_lints/src')
29 files changed, 1333 insertions, 420 deletions
diff --git a/clippy_lints/src/declared_lints.rs b/clippy_lints/src/declared_lints.rs index f73f1ed18f8..a4d40df52e7 100644 --- a/clippy_lints/src/declared_lints.rs +++ b/clippy_lints/src/declared_lints.rs @@ -211,8 +211,6 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[ crate::implicit_saturating_sub::IMPLICIT_SATURATING_SUB_INFO, crate::implied_bounds_in_impls::IMPLIED_BOUNDS_IN_IMPLS_INFO, crate::inconsistent_struct_constructor::INCONSISTENT_STRUCT_CONSTRUCTOR_INFO, - crate::incorrect_impls::INCORRECT_CLONE_IMPL_ON_COPY_TYPE_INFO, - crate::incorrect_impls::INCORRECT_PARTIAL_ORD_IMPL_ON_ORD_TYPE_INFO, crate::index_refutable_slice::INDEX_REFUTABLE_SLICE_INFO, crate::indexing_slicing::INDEXING_SLICING_INFO, crate::indexing_slicing::OUT_OF_BOUNDS_INDEXING_INFO, @@ -365,6 +363,7 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[ crate::methods::ITER_NTH_ZERO_INFO, crate::methods::ITER_ON_EMPTY_COLLECTIONS_INFO, crate::methods::ITER_ON_SINGLE_ITEMS_INFO, + crate::methods::ITER_OUT_OF_BOUNDS_INFO, crate::methods::ITER_OVEREAGER_CLONED_INFO, crate::methods::ITER_SKIP_NEXT_INFO, crate::methods::ITER_SKIP_ZERO_INFO, @@ -456,6 +455,7 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[ crate::misc_early::ZERO_PREFIXED_LITERAL_INFO, crate::mismatching_type_param_order::MISMATCHING_TYPE_PARAM_ORDER_INFO, crate::missing_assert_message::MISSING_ASSERT_MESSAGE_INFO, + crate::missing_asserts_for_indexing::MISSING_ASSERTS_FOR_INDEXING_INFO, crate::missing_const_for_fn::MISSING_CONST_FOR_FN_INFO, crate::missing_doc::MISSING_DOCS_IN_PRIVATE_ITEMS_INFO, crate::missing_enforced_import_rename::MISSING_ENFORCED_IMPORT_RENAMES_INFO, @@ -496,6 +496,8 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[ crate::no_effect::NO_EFFECT_UNDERSCORE_BINDING_INFO, crate::no_effect::UNNECESSARY_OPERATION_INFO, crate::no_mangle_with_rust_abi::NO_MANGLE_WITH_RUST_ABI_INFO, + crate::non_canonical_impls::NON_CANONICAL_CLONE_IMPL_INFO, + crate::non_canonical_impls::NON_CANONICAL_PARTIAL_ORD_IMPL_INFO, crate::non_copy_const::BORROW_INTERIOR_MUTABLE_CONST_INFO, crate::non_copy_const::DECLARE_INTERIOR_MUTABLE_CONST_INFO, crate::non_expressive_names::JUST_UNDERSCORES_AND_DIGITS_INFO, diff --git a/clippy_lints/src/default_union_representation.rs b/clippy_lints/src/default_union_representation.rs index 03b5a2d6d08..bbce6e1dd8f 100644 --- a/clippy_lints/src/default_union_representation.rs +++ b/clippy_lints/src/default_union_representation.rs @@ -69,6 +69,9 @@ impl<'tcx> LateLintPass<'tcx> for DefaultUnionRepresentation { } /// Returns true if the given item is a union with at least two non-ZST fields. +/// (ZST fields having an arbitrary offset is completely inconsequential, and +/// if there is only one field left after ignoring ZST fields then the offset +/// of that field does not matter either.) fn is_union_with_two_non_zst_fields(cx: &LateContext<'_>, item: &Item<'_>) -> bool { if let ItemKind::Union(data, _) = &item.kind { data.fields().iter().filter(|f| !is_zst(cx, f.ty)).count() >= 2 diff --git a/clippy_lints/src/dereference.rs b/clippy_lints/src/dereference.rs index 58c27855000..8090f821d1f 100644 --- a/clippy_lints/src/dereference.rs +++ b/clippy_lints/src/dereference.rs @@ -3,7 +3,7 @@ use clippy_utils::mir::{enclosing_mir, expr_local, local_assignments, used_exact use clippy_utils::msrvs::{self, Msrv}; use clippy_utils::source::{snippet_with_applicability, snippet_with_context}; use clippy_utils::sugg::has_enclosing_paren; -use clippy_utils::ty::{is_copy, peel_mid_ty_refs}; +use clippy_utils::ty::{implements_trait, is_copy, peel_mid_ty_refs}; use clippy_utils::{ expr_use_ctxt, get_parent_expr, get_parent_node, is_lint_allowed, path_to_local, DefinedTy, ExprUseNode, }; @@ -33,7 +33,6 @@ use rustc_middle::ty::{ use rustc_session::{declare_tool_lint, impl_lint_pass}; use rustc_span::symbol::sym; use rustc_span::{Span, Symbol}; -use rustc_trait_selection::infer::InferCtxtExt as _; use rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt as _; use rustc_trait_selection::traits::{Obligation, ObligationCause}; use std::collections::VecDeque; @@ -452,13 +451,12 @@ impl<'tcx> LateLintPass<'tcx> for Dereferencing<'tcx> { // Trait methods taking `self` arg_ty } && impl_ty.is_ref() - && cx.tcx.infer_ctxt().build() - .type_implements_trait( - trait_id, - [impl_ty.into()].into_iter().chain(args.iter().copied()), - cx.param_env, - ) - .must_apply_modulo_regions() + && implements_trait( + cx, + impl_ty, + trait_id, + &args[..cx.tcx.generics_of(trait_id).params.len() - 1], + ) { false } else { @@ -609,12 +607,14 @@ impl<'tcx> LateLintPass<'tcx> for Dereferencing<'tcx> { adjusted_ty, }, )); - } else if stability.is_deref_stable() { + } else if stability.is_deref_stable() + && let Some(parent) = get_parent_expr(cx, expr) + { self.state = Some(( State::ExplicitDeref { mutability: None }, StateData { - span: expr.span, - hir_id: expr.hir_id, + span: parent.span, + hir_id: parent.hir_id, adjusted_ty, }, )); @@ -1399,6 +1399,13 @@ fn report<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, state: State, data return; } + if let ExprKind::Field(parent_expr, _) = expr.kind + && let ty::Adt(adt, _) = cx.typeck_results().expr_ty(parent_expr).kind() + && adt.is_union() + { + // Auto deref does not apply on union field + return; + } span_lint_hir_and_then( cx, EXPLICIT_AUTO_DEREF, diff --git a/clippy_lints/src/derivable_impls.rs b/clippy_lints/src/derivable_impls.rs index 9a85cc4ce2d..d2bfc4f8e27 100644 --- a/clippy_lints/src/derivable_impls.rs +++ b/clippy_lints/src/derivable_impls.rs @@ -217,8 +217,7 @@ impl<'tcx> LateLintPass<'tcx> for DerivableImpls { if let &Adt(adt_def, args) = cx.tcx.type_of(item.owner_id).instantiate_identity().kind(); if let attrs = cx.tcx.hir().attrs(item.hir_id()); if !attrs.iter().any(|attr| attr.doc_str().is_some()); - if let child_attrs = cx.tcx.hir().attrs(impl_item_hir); - if !child_attrs.iter().any(|attr| attr.doc_str().is_some()); + if cx.tcx.hir().attrs(impl_item_hir).is_empty(); then { if adt_def.is_struct() { diff --git a/clippy_lints/src/disallowed_macros.rs b/clippy_lints/src/disallowed_macros.rs index 1971cab64ef..7469f813ef8 100644 --- a/clippy_lints/src/disallowed_macros.rs +++ b/clippy_lints/src/disallowed_macros.rs @@ -1,8 +1,9 @@ use clippy_utils::diagnostics::span_lint_and_then; use clippy_utils::macros::macro_backtrace; +use rustc_ast::Attribute; use rustc_data_structures::fx::FxHashSet; use rustc_hir::def_id::DefIdMap; -use rustc_hir::{Expr, ForeignItem, HirId, ImplItem, Item, Pat, Path, Stmt, TraitItem, Ty}; +use rustc_hir::{Expr, ExprKind, ForeignItem, HirId, ImplItem, Item, Pat, Path, Stmt, TraitItem, Ty}; use rustc_lint::{LateContext, LateLintPass}; use rustc_session::{declare_tool_lint, impl_lint_pass}; use rustc_span::{ExpnId, Span}; @@ -111,6 +112,10 @@ impl LateLintPass<'_> for DisallowedMacros { fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) { self.check(cx, expr.span); + // `$t + $t` can have the context of $t, check also the span of the binary operator + if let ExprKind::Binary(op, ..) = expr.kind { + self.check(cx, op.span); + } } fn check_stmt(&mut self, cx: &LateContext<'_>, stmt: &Stmt<'_>) { @@ -147,4 +152,8 @@ impl LateLintPass<'_> for DisallowedMacros { fn check_path(&mut self, cx: &LateContext<'_>, path: &Path<'_>, _: HirId) { self.check(cx, path.span); } + + fn check_attribute(&mut self, cx: &LateContext<'_>, attr: &Attribute) { + self.check(cx, attr.span); + } } diff --git a/clippy_lints/src/doc.rs b/clippy_lints/src/doc.rs index d8f2fbcea00..4498e9ccdec 100644 --- a/clippy_lints/src/doc.rs +++ b/clippy_lints/src/doc.rs @@ -472,7 +472,7 @@ struct DocHeaders { fn check_attrs(cx: &LateContext<'_>, valid_idents: &FxHashSet<String>, attrs: &[Attribute]) -> Option<DocHeaders> { /// We don't want the parser to choke on intra doc links. Since we don't - /// actually care about rendering them, just pretend that all broken links are + /// actually care about rendering them, just pretend that all broken links /// point to a fake address. #[expect(clippy::unnecessary_wraps)] // we're following a type signature fn fake_broken_link_callback<'a>(_: BrokenLink<'_>) -> Option<(CowStr<'a>, CowStr<'a>)> { diff --git a/clippy_lints/src/if_then_some_else_none.rs b/clippy_lints/src/if_then_some_else_none.rs index ab6ad3f3b3a..e2d19e24557 100644 --- a/clippy_lints/src/if_then_some_else_none.rs +++ b/clippy_lints/src/if_then_some_else_none.rs @@ -6,7 +6,7 @@ use clippy_utils::sugg::Sugg; use clippy_utils::{contains_return, higher, is_else_clause, is_res_lang_ctor, path_res, peel_blocks}; use rustc_errors::Applicability; use rustc_hir::LangItem::{OptionNone, OptionSome}; -use rustc_hir::{Expr, ExprKind, Stmt, StmtKind}; +use rustc_hir::{Expr, ExprKind}; use rustc_lint::{LateContext, LateLintPass, LintContext}; use rustc_middle::lint::in_external_macro; use rustc_session::{declare_tool_lint, impl_lint_pass}; @@ -83,7 +83,7 @@ impl<'tcx> LateLintPass<'tcx> for IfThenSomeElseNone { && then_expr.span.ctxt() == ctxt && is_res_lang_ctor(cx, path_res(cx, then_call), OptionSome) && is_res_lang_ctor(cx, path_res(cx, peel_blocks(els)), OptionNone) - && !stmts_contains_early_return(then_block.stmts) + && !contains_return(then_block.stmts) { let mut app = Applicability::Unspecified; let cond_snip = Sugg::hir_with_context(cx, cond, expr.span.ctxt(), "[condition]", &mut app).maybe_par().to_string(); @@ -116,17 +116,3 @@ impl<'tcx> LateLintPass<'tcx> for IfThenSomeElseNone { extract_msrv_attr!(LateContext); } - -fn stmts_contains_early_return(stmts: &[Stmt<'_>]) -> bool { - stmts.iter().any(|stmt| { - let Stmt { - kind: StmtKind::Semi(e), - .. - } = stmt - else { - return false; - }; - - contains_return(e) - }) -} diff --git a/clippy_lints/src/ignored_unit_patterns.rs b/clippy_lints/src/ignored_unit_patterns.rs index c635120b882..d8ead1c9d9f 100644 --- a/clippy_lints/src/ignored_unit_patterns.rs +++ b/clippy_lints/src/ignored_unit_patterns.rs @@ -1,5 +1,5 @@ use clippy_utils::diagnostics::span_lint_and_sugg; -use hir::PatKind; +use hir::{Node, PatKind}; use rustc_errors::Applicability; use rustc_hir as hir; use rustc_lint::{LateContext, LateLintPass}; @@ -37,6 +37,17 @@ declare_lint_pass!(IgnoredUnitPatterns => [IGNORED_UNIT_PATTERNS]); impl<'tcx> LateLintPass<'tcx> for IgnoredUnitPatterns { fn check_pat(&mut self, cx: &LateContext<'tcx>, pat: &'tcx hir::Pat<'tcx>) { + match cx.tcx.hir().get_parent(pat.hir_id) { + Node::Param(param) if matches!(cx.tcx.hir().get_parent(param.hir_id), Node::Item(_)) => { + // Ignore function parameters + return; + }, + Node::Local(local) if local.ty.is_some() => { + // Ignore let bindings with explicit type + return; + }, + _ => {}, + } if matches!(pat.kind, PatKind::Wild) && cx.typeck_results().pat_ty(pat).is_unit() { span_lint_and_sugg( cx, diff --git a/clippy_lints/src/implied_bounds_in_impls.rs b/clippy_lints/src/implied_bounds_in_impls.rs index c6d1acad3a0..ec9044bba5c 100644 --- a/clippy_lints/src/implied_bounds_in_impls.rs +++ b/clippy_lints/src/implied_bounds_in_impls.rs @@ -1,7 +1,7 @@ use clippy_utils::diagnostics::span_lint_and_then; use clippy_utils::source::snippet; use rustc_errors::{Applicability, SuggestionStyle}; -use rustc_hir::def_id::LocalDefId; +use rustc_hir::def_id::{DefId, LocalDefId}; use rustc_hir::intravisit::FnKind; use rustc_hir::{ Body, FnDecl, FnRetTy, GenericArg, GenericBound, ImplItem, ImplItemKind, ItemKind, TraitBoundModifier, TraitItem, @@ -9,7 +9,7 @@ use rustc_hir::{ }; use rustc_hir_analysis::hir_ty_to_ty; use rustc_lint::{LateContext, LateLintPass}; -use rustc_middle::ty::{self, ClauseKind, TyCtxt}; +use rustc_middle::ty::{self, ClauseKind, Generics, Ty, TyCtxt}; use rustc_session::{declare_lint_pass, declare_tool_lint}; use rustc_span::Span; @@ -45,52 +45,169 @@ declare_clippy_lint! { /// ``` #[clippy::version = "1.73.0"] pub IMPLIED_BOUNDS_IN_IMPLS, - complexity, + nursery, "specifying bounds that are implied by other bounds in `impl Trait` type" } declare_lint_pass!(ImpliedBoundsInImpls => [IMPLIED_BOUNDS_IN_IMPLS]); -/// This function tries to, for all type parameters in a supertype predicate `GenericTrait<U>`, -/// check if the substituted type in the implied-by bound matches with what's subtituted in the -/// implied type. +#[allow(clippy::too_many_arguments)] +fn emit_lint( + cx: &LateContext<'_>, + poly_trait: &rustc_hir::PolyTraitRef<'_>, + opaque_ty: &rustc_hir::OpaqueTy<'_>, + index: usize, + // The bindings that were implied + implied_bindings: &[rustc_hir::TypeBinding<'_>], + // The original bindings that `implied_bindings` are implied from + implied_by_bindings: &[rustc_hir::TypeBinding<'_>], + implied_by_args: &[GenericArg<'_>], + implied_by_span: Span, +) { + let implied_by = snippet(cx, implied_by_span, ".."); + + span_lint_and_then( + cx, + IMPLIED_BOUNDS_IN_IMPLS, + poly_trait.span, + &format!("this bound is already specified as the supertrait of `{implied_by}`"), + |diag| { + // If we suggest removing a bound, we may also need to extend the span + // to include the `+` token that is ahead or behind, + // so we don't end up with something like `impl + B` or `impl A + ` + + let implied_span_extended = if let Some(next_bound) = opaque_ty.bounds.get(index + 1) { + poly_trait.span.to(next_bound.span().shrink_to_lo()) + } else if index > 0 + && let Some(prev_bound) = opaque_ty.bounds.get(index - 1) + { + prev_bound.span().shrink_to_hi().to(poly_trait.span.shrink_to_hi()) + } else { + poly_trait.span + }; + + let mut sugg = vec![(implied_span_extended, String::new())]; + + // We also might need to include associated type binding that were specified in the implied bound, + // but omitted in the implied-by bound: + // `fn f() -> impl Deref<Target = u8> + DerefMut` + // If we're going to suggest removing `Deref<..>`, we'll need to put `<Target = u8>` on `DerefMut` + let omitted_assoc_tys: Vec<_> = implied_bindings + .iter() + .filter(|binding| !implied_by_bindings.iter().any(|b| b.ident == binding.ident)) + .collect(); + + if !omitted_assoc_tys.is_empty() { + // `<>` needs to be added if there aren't yet any generic arguments or bindings + let needs_angle_brackets = implied_by_args.is_empty() && implied_by_bindings.is_empty(); + let insert_span = match (implied_by_args, implied_by_bindings) { + ([.., arg], [.., binding]) => arg.span().max(binding.span).shrink_to_hi(), + ([.., arg], []) => arg.span().shrink_to_hi(), + ([], [.., binding]) => binding.span.shrink_to_hi(), + ([], []) => implied_by_span.shrink_to_hi(), + }; + + let mut associated_tys_sugg = if needs_angle_brackets { + "<".to_owned() + } else { + // If angle brackets aren't needed (i.e., there are already generic arguments or bindings), + // we need to add a comma: + // `impl A<B, C >` + // ^ if we insert `Assoc=i32` without a comma here, that'd be invalid syntax: + // `impl A<B, C Assoc=i32>` + ", ".to_owned() + }; + + for (index, binding) in omitted_assoc_tys.into_iter().enumerate() { + if index > 0 { + associated_tys_sugg += ", "; + } + associated_tys_sugg += &snippet(cx, binding.span, ".."); + } + if needs_angle_brackets { + associated_tys_sugg += ">"; + } + sugg.push((insert_span, associated_tys_sugg)); + } + + diag.multipart_suggestion_with_style( + "try removing this bound", + sugg, + Applicability::MachineApplicable, + SuggestionStyle::ShowAlways, + ); + }, + ); +} + +/// Tries to "resolve" a type. +/// The index passed to this function must start with `Self=0`, i.e. it must be a valid +/// type parameter index. +/// If the index is out of bounds, it means that the generic parameter has a default type. +fn try_resolve_type<'tcx>( + tcx: TyCtxt<'tcx>, + args: &'tcx [GenericArg<'tcx>], + generics: &'tcx Generics, + index: usize, +) -> Option<Ty<'tcx>> { + match args.get(index - 1) { + Some(GenericArg::Type(ty)) => Some(hir_ty_to_ty(tcx, ty)), + Some(_) => None, + None => Some(tcx.type_of(generics.params[index].def_id).skip_binder()), + } +} + +/// This function tries to, for all generic type parameters in a supertrait predicate `trait ...<U>: +/// GenericTrait<U>`, check if the substituted type in the implied-by bound matches with what's +/// subtituted in the implied bound. /// /// Consider this example. /// ```rust,ignore /// trait GenericTrait<T> {} /// trait GenericSubTrait<T, U, V>: GenericTrait<U> {} -/// ^ trait_predicate_args: [Self#0, U#2] +/// ^^^^^^^^^^^^^^^ trait_predicate_args: [Self#0, U#2] +/// (the Self#0 is implicit: `<Self as GenericTrait<U>>`) /// impl GenericTrait<i32> for () {} /// impl GenericSubTrait<(), i32, ()> for () {} -/// impl GenericSubTrait<(), [u8; 8], ()> for () {} +/// impl GenericSubTrait<(), i64, ()> for () {} /// -/// fn f() -> impl GenericTrait<i32> + GenericSubTrait<(), [u8; 8], ()> { -/// ^^^ implied_args ^^^^^^^^^^^^^^^ implied_by_args -/// (we are interested in `[u8; 8]` specifically, as that -/// is what `U` in `GenericTrait<U>` is substituted with) -/// () +/// fn f() -> impl GenericTrait<i32> + GenericSubTrait<(), i64, ()> { +/// ^^^ implied_args ^^^^^^^^^^^ implied_by_args +/// (we are interested in `i64` specifically, as that +/// is what `U` in `GenericTrait<U>` is substituted with) /// } /// ``` -/// Here i32 != [u8; 8], so this will return false. -fn is_same_generics( - tcx: TyCtxt<'_>, - trait_predicate_args: &[ty::GenericArg<'_>], - implied_by_args: &[GenericArg<'_>], - implied_args: &[GenericArg<'_>], +/// Here i32 != i64, so this will return false. +fn is_same_generics<'tcx>( + tcx: TyCtxt<'tcx>, + trait_predicate_args: &'tcx [ty::GenericArg<'tcx>], + implied_by_args: &'tcx [GenericArg<'tcx>], + implied_args: &'tcx [GenericArg<'tcx>], + implied_by_def_id: DefId, + implied_def_id: DefId, ) -> bool { + // Get the generics of the two traits to be able to get default generic parameter. + let implied_by_generics = tcx.generics_of(implied_by_def_id); + let implied_generics = tcx.generics_of(implied_def_id); + trait_predicate_args .iter() .enumerate() .skip(1) // skip `Self` implicit arg .all(|(arg_index, arg)| { - if let Some(ty) = arg.as_type() - && let &ty::Param(ty::ParamTy{ index, .. }) = ty.kind() - // Since `trait_predicate_args` and type params in traits start with `Self=0` - // and generic argument lists `GenericTrait<i32>` don't have `Self`, - // we need to subtract 1 from the index. - && let GenericArg::Type(ty_a) = implied_by_args[index as usize - 1] - && let GenericArg::Type(ty_b) = implied_args[arg_index - 1] - { - hir_ty_to_ty(tcx, ty_a) == hir_ty_to_ty(tcx, ty_b) + if let Some(ty) = arg.as_type() { + if let &ty::Param(ty::ParamTy { index, .. }) = ty.kind() + // `index == 0` means that it's referring to `Self`, + // in which case we don't try to substitute it + && index != 0 + && let Some(ty_a) = try_resolve_type(tcx, implied_by_args, implied_by_generics, index as usize) + && let Some(ty_b) = try_resolve_type(tcx, implied_args, implied_generics, arg_index) + { + ty_a == ty_b + } else if let Some(ty_b) = try_resolve_type(tcx, implied_args, implied_generics, arg_index) { + ty == ty_b + } else { + false + } } else { false } @@ -121,7 +238,7 @@ fn check(cx: &LateContext<'_>, decl: &FnDecl<'_>) { && let predicates = cx.tcx.super_predicates_of(trait_def_id).predicates && !predicates.is_empty() // If the trait has no supertrait, there is nothing to add. { - Some((bound.span(), path.args.map_or([].as_slice(), |a| a.args), predicates)) + Some((bound.span(), path, predicates, trait_def_id)) } else { None } @@ -134,43 +251,42 @@ fn check(cx: &LateContext<'_>, decl: &FnDecl<'_>) { if let GenericBound::Trait(poly_trait, TraitBoundModifier::None) = bound && let [.., path] = poly_trait.trait_ref.path.segments && let implied_args = path.args.map_or([].as_slice(), |a| a.args) + && let implied_bindings = path.args.map_or([].as_slice(), |a| a.bindings) && let Some(def_id) = poly_trait.trait_ref.path.res.opt_def_id() - && let Some(implied_by_span) = implied_bounds.iter().find_map(|&(span, implied_by_args, preds)| { - preds.iter().find_map(|(clause, _)| { - if let ClauseKind::Trait(tr) = clause.kind().skip_binder() - && tr.def_id() == def_id - && is_same_generics(cx.tcx, tr.trait_ref.args, implied_by_args, implied_args) - { - Some(span) - } else { - None - } + && let Some((implied_by_span, implied_by_args, implied_by_bindings)) = implied_bounds + .iter() + .find_map(|&(span, implied_by_path, preds, implied_by_def_id)| { + let implied_by_args = implied_by_path.args.map_or([].as_slice(), |a| a.args); + let implied_by_bindings = implied_by_path.args.map_or([].as_slice(), |a| a.bindings); + + preds.iter().find_map(|(clause, _)| { + if let ClauseKind::Trait(tr) = clause.kind().skip_binder() + && tr.def_id() == def_id + && is_same_generics( + cx.tcx, + tr.trait_ref.args, + implied_by_args, + implied_args, + implied_by_def_id, + def_id, + ) + { + Some((span, implied_by_args, implied_by_bindings)) + } else { + None + } + }) }) - }) { - let implied_by = snippet(cx, implied_by_span, ".."); - span_lint_and_then( - cx, IMPLIED_BOUNDS_IN_IMPLS, - poly_trait.span, - &format!("this bound is already specified as the supertrait of `{implied_by}`"), - |diag| { - // If we suggest removing a bound, we may also need extend the span - // to include the `+` token, so we don't end up with something like `impl + B` - - let implied_span_extended = if let Some(next_bound) = opaque_ty.bounds.get(index + 1) { - poly_trait.span.to(next_bound.span().shrink_to_lo()) - } else { - poly_trait.span - }; - - diag.span_suggestion_with_style( - implied_span_extended, - "try removing this bound", - "", - Applicability::MachineApplicable, - SuggestionStyle::ShowAlways - ); - } + emit_lint( + cx, + poly_trait, + opaque_ty, + index, + implied_bindings, + implied_by_bindings, + implied_by_args, + implied_by_span ); } } diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs index 20fdf26dc52..f52614b6208 100644 --- a/clippy_lints/src/lib.rs +++ b/clippy_lints/src/lib.rs @@ -156,7 +156,6 @@ mod implicit_saturating_add; mod implicit_saturating_sub; mod implied_bounds_in_impls; mod inconsistent_struct_constructor; -mod incorrect_impls; mod index_refutable_slice; mod indexing_slicing; mod infinite_iter; @@ -212,6 +211,7 @@ mod misc; mod misc_early; mod mismatching_type_param_order; mod missing_assert_message; +mod missing_asserts_for_indexing; mod missing_const_for_fn; mod missing_doc; mod missing_enforced_import_rename; @@ -245,6 +245,7 @@ mod neg_multiply; mod new_without_default; mod no_effect; mod no_mangle_with_rust_abi; +mod non_canonical_impls; mod non_copy_const; mod non_expressive_names; mod non_octal_unix_permissions; @@ -697,7 +698,8 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: }); store.register_late_pass(|_| Box::<shadow::Shadow>::default()); store.register_late_pass(|_| Box::new(unit_types::UnitTypes)); - store.register_late_pass(move |_| Box::new(loops::Loops::new(msrv()))); + let enforce_iter_loop_reborrow = conf.enforce_iter_loop_reborrow; + store.register_late_pass(move |_| Box::new(loops::Loops::new(msrv(), enforce_iter_loop_reborrow))); store.register_late_pass(|_| Box::<main_recursion::MainRecursion>::default()); store.register_late_pass(|_| Box::new(lifetimes::Lifetimes)); store.register_late_pass(|_| Box::new(entry::HashMapPass)); @@ -1070,7 +1072,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: avoid_breaking_exported_api, )) }); - store.register_late_pass(|_| Box::new(incorrect_impls::IncorrectImpls)); + store.register_late_pass(|_| Box::new(non_canonical_impls::NonCanonicalImpls)); store.register_late_pass(move |_| { Box::new(single_call_fn::SingleCallFn { avoid_breaking_exported_api, @@ -1101,6 +1103,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: store.register_late_pass(|_| Box::new(ignored_unit_patterns::IgnoredUnitPatterns)); store.register_late_pass(|_| Box::<reserve_after_initialization::ReserveAfterInitialization>::default()); store.register_late_pass(|_| Box::new(implied_bounds_in_impls::ImpliedBoundsInImpls)); + store.register_late_pass(|_| Box::new(missing_asserts_for_indexing::MissingAssertsForIndexing)); // add lints here, do not remove this comment, it's used in `new_lint` } diff --git a/clippy_lints/src/loops/explicit_iter_loop.rs b/clippy_lints/src/loops/explicit_iter_loop.rs index 7b8c88235a9..6ab256ef001 100644 --- a/clippy_lints/src/loops/explicit_iter_loop.rs +++ b/clippy_lints/src/loops/explicit_iter_loop.rs @@ -13,8 +13,14 @@ use rustc_middle::ty::adjustment::{Adjust, Adjustment, AutoBorrow, AutoBorrowMut use rustc_middle::ty::{self, EarlyBinder, Ty, TypeAndMut}; use rustc_span::sym; -pub(super) fn check(cx: &LateContext<'_>, self_arg: &Expr<'_>, call_expr: &Expr<'_>, msrv: &Msrv) { - let Some((adjust, ty)) = is_ref_iterable(cx, self_arg, call_expr) else { +pub(super) fn check( + cx: &LateContext<'_>, + self_arg: &Expr<'_>, + call_expr: &Expr<'_>, + msrv: &Msrv, + enforce_iter_loop_reborrow: bool, +) { + let Some((adjust, ty)) = is_ref_iterable(cx, self_arg, call_expr, enforce_iter_loop_reborrow) else { return; }; if let ty::Array(_, count) = *ty.peel_refs().kind() { @@ -102,6 +108,7 @@ fn is_ref_iterable<'tcx>( cx: &LateContext<'tcx>, self_arg: &Expr<'_>, call_expr: &Expr<'_>, + enforce_iter_loop_reborrow: bool, ) -> Option<(AdjustKind, Ty<'tcx>)> { let typeck = cx.typeck_results(); if let Some(trait_id) = cx.tcx.get_diagnostic_item(sym::IntoIterator) @@ -142,7 +149,8 @@ fn is_ref_iterable<'tcx>( { return Some((AdjustKind::None, self_ty)); } - } else if let ty::Ref(region, ty, Mutability::Mut) = *self_ty.kind() + } else if enforce_iter_loop_reborrow + && let ty::Ref(region, ty, Mutability::Mut) = *self_ty.kind() && let Some(mutbl) = mutbl { // Attempt to reborrow the mutable reference @@ -186,7 +194,8 @@ fn is_ref_iterable<'tcx>( }, .. ] => { - if target != self_ty + if enforce_iter_loop_reborrow + && target != self_ty && implements_trait(cx, target, trait_id, &[]) && let Some(ty) = make_normalized_projection(cx.tcx, cx.param_env, trait_id, sym!(IntoIter), [target]) diff --git a/clippy_lints/src/loops/mod.rs b/clippy_lints/src/loops/mod.rs index ffd29ab7630..1fb16adad7a 100644 --- a/clippy_lints/src/loops/mod.rs +++ b/clippy_lints/src/loops/mod.rs @@ -609,10 +609,14 @@ declare_clippy_lint! { pub struct Loops { msrv: Msrv, + enforce_iter_loop_reborrow: bool, } impl Loops { - pub fn new(msrv: Msrv) -> Self { - Self { msrv } + pub fn new(msrv: Msrv, enforce_iter_loop_reborrow: bool) -> Self { + Self { + msrv, + enforce_iter_loop_reborrow, + } } } impl_lint_pass!(Loops => [ @@ -719,7 +723,7 @@ impl Loops { if let ExprKind::MethodCall(method, self_arg, [], _) = arg.kind { match method.ident.as_str() { "iter" | "iter_mut" => { - explicit_iter_loop::check(cx, self_arg, arg, &self.msrv); + explicit_iter_loop::check(cx, self_arg, arg, &self.msrv, self.enforce_iter_loop_reborrow); }, "into_iter" => { explicit_into_iter_loop::check(cx, self_arg, arg); diff --git a/clippy_lints/src/loops/never_loop.rs b/clippy_lints/src/loops/never_loop.rs index cc19ac55e5e..3d8a4cd948a 100644 --- a/clippy_lints/src/loops/never_loop.rs +++ b/clippy_lints/src/loops/never_loop.rs @@ -1,13 +1,13 @@ use super::utils::make_iterator_snippet; use super::NEVER_LOOP; -use clippy_utils::consts::{constant, Constant}; use clippy_utils::diagnostics::span_lint_and_then; use clippy_utils::higher::ForLoop; +use clippy_utils::macros::root_macro_call_first_node; use clippy_utils::source::snippet; use rustc_errors::Applicability; use rustc_hir::{Block, Destination, Expr, ExprKind, HirId, InlineAsmOperand, Pat, Stmt, StmtKind}; use rustc_lint::LateContext; -use rustc_span::Span; +use rustc_span::{sym, Span}; use std::iter::{once, Iterator}; pub(super) fn check<'tcx>( @@ -18,7 +18,7 @@ pub(super) fn check<'tcx>( for_loop: Option<&ForLoop<'_>>, ) { match never_loop_block(cx, block, &mut Vec::new(), loop_id) { - NeverLoopResult::AlwaysBreak => { + NeverLoopResult::Diverging => { span_lint_and_then(cx, NEVER_LOOP, span, "this loop never actually loops", |diag| { if let Some(ForLoop { arg: iterator, @@ -39,67 +39,76 @@ pub(super) fn check<'tcx>( } }); }, - NeverLoopResult::MayContinueMainLoop | NeverLoopResult::Otherwise => (), - NeverLoopResult::IgnoreUntilEnd(_) => unreachable!(), + NeverLoopResult::MayContinueMainLoop | NeverLoopResult::Normal => (), } } +/// The `never_loop` analysis keeps track of three things: +/// +/// * Has any (reachable) code path hit a `continue` of the main loop? +/// * Is the current code path diverging (that is, the next expression is not reachable) +/// * For each block label `'a` inside the main loop, has any (reachable) code path encountered a +/// `break 'a`? +/// +/// The first two bits of information are in this enum, and the last part is in the +/// `local_labels` variable, which contains a list of `(block_id, reachable)` pairs ordered by +/// scope. #[derive(Copy, Clone)] enum NeverLoopResult { - // A break/return always get triggered but not necessarily for the main loop. - AlwaysBreak, - // A continue may occur for the main loop. + /// A continue may occur for the main loop. MayContinueMainLoop, - // Ignore everything until the end of the block with this id - IgnoreUntilEnd(HirId), - Otherwise, + /// We have not encountered any main loop continue, + /// but we are diverging (subsequent control flow is not reachable) + Diverging, + /// We have not encountered any main loop continue, + /// and subsequent control flow is (possibly) reachable + Normal, } #[must_use] fn absorb_break(arg: NeverLoopResult) -> NeverLoopResult { match arg { - NeverLoopResult::AlwaysBreak | NeverLoopResult::Otherwise => NeverLoopResult::Otherwise, + NeverLoopResult::Diverging | NeverLoopResult::Normal => NeverLoopResult::Normal, NeverLoopResult::MayContinueMainLoop => NeverLoopResult::MayContinueMainLoop, - NeverLoopResult::IgnoreUntilEnd(id) => NeverLoopResult::IgnoreUntilEnd(id), } } // Combine two results for parts that are called in order. #[must_use] -fn combine_seq(first: NeverLoopResult, second: NeverLoopResult) -> NeverLoopResult { +fn combine_seq(first: NeverLoopResult, second: impl FnOnce() -> NeverLoopResult) -> NeverLoopResult { match first { - NeverLoopResult::AlwaysBreak | NeverLoopResult::MayContinueMainLoop | NeverLoopResult::IgnoreUntilEnd(_) => { - first - }, - NeverLoopResult::Otherwise => second, + NeverLoopResult::Diverging | NeverLoopResult::MayContinueMainLoop => first, + NeverLoopResult::Normal => second(), + } +} + +// Combine an iterator of results for parts that are called in order. +#[must_use] +fn combine_seq_many(iter: impl IntoIterator<Item = NeverLoopResult>) -> NeverLoopResult { + for e in iter { + if let NeverLoopResult::Diverging | NeverLoopResult::MayContinueMainLoop = e { + return e; + } } + NeverLoopResult::Normal } // Combine two results where only one of the part may have been executed. #[must_use] -fn combine_branches(b1: NeverLoopResult, b2: NeverLoopResult, ignore_ids: &[HirId]) -> NeverLoopResult { +fn combine_branches(b1: NeverLoopResult, b2: NeverLoopResult) -> NeverLoopResult { match (b1, b2) { - (NeverLoopResult::IgnoreUntilEnd(a), NeverLoopResult::IgnoreUntilEnd(b)) => { - if ignore_ids.iter().find(|&e| e == &a || e == &b).unwrap() == &a { - NeverLoopResult::IgnoreUntilEnd(b) - } else { - NeverLoopResult::IgnoreUntilEnd(a) - } - }, - (i @ NeverLoopResult::IgnoreUntilEnd(_), NeverLoopResult::AlwaysBreak) - | (NeverLoopResult::AlwaysBreak, i @ NeverLoopResult::IgnoreUntilEnd(_)) => i, - (NeverLoopResult::AlwaysBreak, NeverLoopResult::AlwaysBreak) => NeverLoopResult::AlwaysBreak, (NeverLoopResult::MayContinueMainLoop, _) | (_, NeverLoopResult::MayContinueMainLoop) => { NeverLoopResult::MayContinueMainLoop }, - (NeverLoopResult::Otherwise, _) | (_, NeverLoopResult::Otherwise) => NeverLoopResult::Otherwise, + (NeverLoopResult::Normal, _) | (_, NeverLoopResult::Normal) => NeverLoopResult::Normal, + (NeverLoopResult::Diverging, NeverLoopResult::Diverging) => NeverLoopResult::Diverging, } } fn never_loop_block<'tcx>( cx: &LateContext<'tcx>, block: &Block<'tcx>, - ignore_ids: &mut Vec<HirId>, + local_labels: &mut Vec<(HirId, bool)>, main_loop_id: HirId, ) -> NeverLoopResult { let iter = block @@ -107,15 +116,21 @@ fn never_loop_block<'tcx>( .iter() .filter_map(stmt_to_expr) .chain(block.expr.map(|expr| (expr, None))); - - iter.map(|(e, els)| { - let e = never_loop_expr(cx, e, ignore_ids, main_loop_id); + combine_seq_many(iter.map(|(e, els)| { + let e = never_loop_expr(cx, e, local_labels, main_loop_id); // els is an else block in a let...else binding els.map_or(e, |els| { - combine_branches(e, never_loop_block(cx, els, ignore_ids, main_loop_id), ignore_ids) + combine_seq(e, || match never_loop_block(cx, els, local_labels, main_loop_id) { + // Returning MayContinueMainLoop here means that + // we will not evaluate the rest of the body + NeverLoopResult::MayContinueMainLoop => NeverLoopResult::MayContinueMainLoop, + // An else block always diverges, so the Normal case should not happen, + // but the analysis is approximate so it might return Normal anyway. + // Returning Normal here says that nothing more happens on the main path + NeverLoopResult::Diverging | NeverLoopResult::Normal => NeverLoopResult::Normal, + }) }) - }) - .fold(NeverLoopResult::Otherwise, combine_seq) + })) } fn stmt_to_expr<'tcx>(stmt: &Stmt<'tcx>) -> Option<(&'tcx Expr<'tcx>, Option<&'tcx Block<'tcx>>)> { @@ -131,76 +146,69 @@ fn stmt_to_expr<'tcx>(stmt: &Stmt<'tcx>) -> Option<(&'tcx Expr<'tcx>, Option<&'t fn never_loop_expr<'tcx>( cx: &LateContext<'tcx>, expr: &Expr<'tcx>, - ignore_ids: &mut Vec<HirId>, + local_labels: &mut Vec<(HirId, bool)>, main_loop_id: HirId, ) -> NeverLoopResult { - match expr.kind { + let result = match expr.kind { ExprKind::Unary(_, e) | ExprKind::Cast(e, _) | ExprKind::Type(e, _) | ExprKind::Field(e, _) | ExprKind::AddrOf(_, _, e) | ExprKind::Repeat(e, _) - | ExprKind::DropTemps(e) => never_loop_expr(cx, e, ignore_ids, main_loop_id), - ExprKind::Let(let_expr) => never_loop_expr(cx, let_expr.init, ignore_ids, main_loop_id), - ExprKind::Array(es) | ExprKind::Tup(es) => never_loop_expr_all(cx, &mut es.iter(), ignore_ids, main_loop_id), + | ExprKind::DropTemps(e) => never_loop_expr(cx, e, local_labels, main_loop_id), + ExprKind::Let(let_expr) => never_loop_expr(cx, let_expr.init, local_labels, main_loop_id), + ExprKind::Array(es) | ExprKind::Tup(es) => never_loop_expr_all(cx, es.iter(), local_labels, main_loop_id), ExprKind::MethodCall(_, receiver, es, _) => never_loop_expr_all( cx, - &mut std::iter::once(receiver).chain(es.iter()), - ignore_ids, + std::iter::once(receiver).chain(es.iter()), + local_labels, main_loop_id, ), ExprKind::Struct(_, fields, base) => { - let fields = never_loop_expr_all(cx, &mut fields.iter().map(|f| f.expr), ignore_ids, main_loop_id); + let fields = never_loop_expr_all(cx, fields.iter().map(|f| f.expr), local_labels, main_loop_id); if let Some(base) = base { - combine_seq(fields, never_loop_expr(cx, base, ignore_ids, main_loop_id)) + combine_seq(fields, || never_loop_expr(cx, base, local_labels, main_loop_id)) } else { fields } }, - ExprKind::Call(e, es) => never_loop_expr_all(cx, &mut once(e).chain(es.iter()), ignore_ids, main_loop_id), + ExprKind::Call(e, es) => never_loop_expr_all(cx, once(e).chain(es.iter()), local_labels, main_loop_id), ExprKind::Binary(_, e1, e2) | ExprKind::Assign(e1, e2, _) | ExprKind::AssignOp(_, e1, e2) - | ExprKind::Index(e1, e2, _) => { - never_loop_expr_all(cx, &mut [e1, e2].iter().copied(), ignore_ids, main_loop_id) - }, + | ExprKind::Index(e1, e2, _) => never_loop_expr_all(cx, [e1, e2].iter().copied(), local_labels, main_loop_id), ExprKind::Loop(b, _, _, _) => { - // Break can come from the inner loop so remove them. - absorb_break(never_loop_block(cx, b, ignore_ids, main_loop_id)) + // We don't attempt to track reachability after a loop, + // just assume there may have been a break somewhere + absorb_break(never_loop_block(cx, b, local_labels, main_loop_id)) }, ExprKind::If(e, e2, e3) => { - let e1 = never_loop_expr(cx, e, ignore_ids, main_loop_id); - let e2 = never_loop_expr(cx, e2, ignore_ids, main_loop_id); - // If we know the `if` condition evaluates to `true`, don't check everything past it; it - // should just return whatever's evaluated for `e1` and `e2` since `e3` is unreachable - if let Some(Constant::Bool(true)) = constant(cx, cx.typeck_results(), e) { - return combine_seq(e1, e2); - } - let e3 = e3.as_ref().map_or(NeverLoopResult::Otherwise, |e| { - never_loop_expr(cx, e, ignore_ids, main_loop_id) - }); - combine_seq(e1, combine_branches(e2, e3, ignore_ids)) + let e1 = never_loop_expr(cx, e, local_labels, main_loop_id); + combine_seq(e1, || { + let e2 = never_loop_expr(cx, e2, local_labels, main_loop_id); + let e3 = e3.as_ref().map_or(NeverLoopResult::Normal, |e| { + never_loop_expr(cx, e, local_labels, main_loop_id) + }); + combine_branches(e2, e3) + }) }, ExprKind::Match(e, arms, _) => { - let e = never_loop_expr(cx, e, ignore_ids, main_loop_id); - if arms.is_empty() { - e - } else { - let arms = never_loop_expr_branch(cx, &mut arms.iter().map(|a| a.body), ignore_ids, main_loop_id); - combine_seq(e, arms) - } + let e = never_loop_expr(cx, e, local_labels, main_loop_id); + combine_seq(e, || { + arms.iter().fold(NeverLoopResult::Diverging, |a, b| { + combine_branches(a, never_loop_expr(cx, b.body, local_labels, main_loop_id)) + }) + }) }, ExprKind::Block(b, l) => { if l.is_some() { - ignore_ids.push(b.hir_id); - } - let ret = never_loop_block(cx, b, ignore_ids, main_loop_id); - if l.is_some() { - ignore_ids.pop(); + local_labels.push((b.hir_id, false)); } + let ret = never_loop_block(cx, b, local_labels, main_loop_id); + let jumped_to = l.is_some() && local_labels.pop().unwrap().1; match ret { - NeverLoopResult::IgnoreUntilEnd(a) if a == b.hir_id => NeverLoopResult::Otherwise, + NeverLoopResult::Diverging if jumped_to => NeverLoopResult::Normal, _ => ret, } }, @@ -211,74 +219,78 @@ fn never_loop_expr<'tcx>( if id == main_loop_id { NeverLoopResult::MayContinueMainLoop } else { - NeverLoopResult::AlwaysBreak + NeverLoopResult::Diverging } }, - // checks if break targets a block instead of a loop - ExprKind::Break(Destination { target_id: Ok(t), .. }, e) if ignore_ids.contains(&t) => e - .map_or(NeverLoopResult::IgnoreUntilEnd(t), |e| { - never_loop_expr(cx, e, ignore_ids, main_loop_id) - }), - ExprKind::Break(_, e) | ExprKind::Ret(e) => e.as_ref().map_or(NeverLoopResult::AlwaysBreak, |e| { - combine_seq( - never_loop_expr(cx, e, ignore_ids, main_loop_id), - NeverLoopResult::AlwaysBreak, - ) - }), - ExprKind::Become(e) => combine_seq( - never_loop_expr(cx, e, ignore_ids, main_loop_id), - NeverLoopResult::AlwaysBreak, - ), - ExprKind::InlineAsm(asm) => asm - .operands - .iter() - .map(|(o, _)| match o { - InlineAsmOperand::In { expr, .. } | InlineAsmOperand::InOut { expr, .. } => { - never_loop_expr(cx, expr, ignore_ids, main_loop_id) - }, - InlineAsmOperand::Out { expr, .. } => { - never_loop_expr_all(cx, &mut expr.iter().copied(), ignore_ids, main_loop_id) - }, - InlineAsmOperand::SplitInOut { in_expr, out_expr, .. } => never_loop_expr_all( - cx, - &mut once(*in_expr).chain(out_expr.iter().copied()), - ignore_ids, - main_loop_id, - ), - InlineAsmOperand::Const { .. } - | InlineAsmOperand::SymFn { .. } - | InlineAsmOperand::SymStatic { .. } => NeverLoopResult::Otherwise, + ExprKind::Break(_, e) | ExprKind::Ret(e) => { + let first = e.as_ref().map_or(NeverLoopResult::Normal, |e| { + never_loop_expr(cx, e, local_labels, main_loop_id) + }); + combine_seq(first, || { + // checks if break targets a block instead of a loop + if let ExprKind::Break(Destination { target_id: Ok(t), .. }, _) = expr.kind { + if let Some((_, reachable)) = local_labels.iter_mut().find(|(label, _)| *label == t) { + *reachable = true; + } + } + NeverLoopResult::Diverging }) - .fold(NeverLoopResult::Otherwise, combine_seq), + }, + ExprKind::Become(e) => combine_seq(never_loop_expr(cx, e, local_labels, main_loop_id), || { + NeverLoopResult::Diverging + }), + ExprKind::InlineAsm(asm) => combine_seq_many(asm.operands.iter().map(|(o, _)| match o { + InlineAsmOperand::In { expr, .. } | InlineAsmOperand::InOut { expr, .. } => { + never_loop_expr(cx, expr, local_labels, main_loop_id) + }, + InlineAsmOperand::Out { expr, .. } => { + never_loop_expr_all(cx, expr.iter().copied(), local_labels, main_loop_id) + }, + InlineAsmOperand::SplitInOut { in_expr, out_expr, .. } => never_loop_expr_all( + cx, + once(*in_expr).chain(out_expr.iter().copied()), + local_labels, + main_loop_id, + ), + InlineAsmOperand::Const { .. } | InlineAsmOperand::SymFn { .. } | InlineAsmOperand::SymStatic { .. } => { + NeverLoopResult::Normal + }, + })), ExprKind::OffsetOf(_, _) | ExprKind::Yield(_, _) | ExprKind::Closure { .. } | ExprKind::Path(_) | ExprKind::ConstBlock(_) | ExprKind::Lit(_) - | ExprKind::Err(_) => NeverLoopResult::Otherwise, + | ExprKind::Err(_) => NeverLoopResult::Normal, + }; + let result = combine_seq(result, || { + if cx.typeck_results().expr_ty(expr).is_never() { + NeverLoopResult::Diverging + } else { + NeverLoopResult::Normal + } + }); + if let NeverLoopResult::Diverging = result && + let Some(macro_call) = root_macro_call_first_node(cx, expr) && + let Some(sym::todo_macro) = cx.tcx.get_diagnostic_name(macro_call.def_id) + { + // We return MayContinueMainLoop here because we treat `todo!()` + // as potentially containing any code, including a continue of the main loop. + // This effectively silences the lint whenever a loop contains this macro anywhere. + NeverLoopResult::MayContinueMainLoop + } else { + result } } fn never_loop_expr_all<'tcx, T: Iterator<Item = &'tcx Expr<'tcx>>>( cx: &LateContext<'tcx>, - es: &mut T, - ignore_ids: &mut Vec<HirId>, - main_loop_id: HirId, -) -> NeverLoopResult { - es.map(|e| never_loop_expr(cx, e, ignore_ids, main_loop_id)) - .fold(NeverLoopResult::Otherwise, combine_seq) -} - -fn never_loop_expr_branch<'tcx, T: Iterator<Item = &'tcx Expr<'tcx>>>( - cx: &LateContext<'tcx>, - e: &mut T, - ignore_ids: &mut Vec<HirId>, + es: T, + local_labels: &mut Vec<(HirId, bool)>, main_loop_id: HirId, ) -> NeverLoopResult { - e.fold(NeverLoopResult::AlwaysBreak, |a, b| { - combine_branches(a, never_loop_expr(cx, b, ignore_ids, main_loop_id), ignore_ids) - }) + combine_seq_many(es.map(|e| never_loop_expr(cx, e, local_labels, main_loop_id))) } fn for_to_if_let_sugg(cx: &LateContext<'_>, iterator: &Expr<'_>, pat: &Pat<'_>) -> String { diff --git a/clippy_lints/src/manual_range_patterns.rs b/clippy_lints/src/manual_range_patterns.rs index 39d8b20d38d..90557b55560 100644 --- a/clippy_lints/src/manual_range_patterns.rs +++ b/clippy_lints/src/manual_range_patterns.rs @@ -1,4 +1,5 @@ -use clippy_utils::diagnostics::span_lint_and_sugg; +use clippy_utils::diagnostics::span_lint_and_then; +use clippy_utils::source::snippet_opt; use rustc_ast::LitKind; use rustc_data_structures::fx::FxHashSet; use rustc_errors::Applicability; @@ -6,6 +7,7 @@ use rustc_hir::{Expr, ExprKind, PatKind, RangeEnd, UnOp}; use rustc_lint::{LateContext, LateLintPass, LintContext}; use rustc_middle::lint::in_external_macro; use rustc_session::{declare_lint_pass, declare_tool_lint}; +use rustc_span::{Span, DUMMY_SP}; declare_clippy_lint! { /// ### What it does @@ -49,6 +51,29 @@ fn expr_as_i128(expr: &Expr<'_>) -> Option<i128> { } } +#[derive(Copy, Clone)] +struct Num { + val: i128, + span: Span, +} + +impl Num { + fn new(expr: &Expr<'_>) -> Option<Self> { + Some(Self { + val: expr_as_i128(expr)?, + span: expr.span, + }) + } + + fn dummy(val: i128) -> Self { + Self { val, span: DUMMY_SP } + } + + fn min(self, other: Self) -> Self { + if self.val < other.val { self } else { other } + } +} + impl LateLintPass<'_> for ManualRangePatterns { fn check_pat(&mut self, cx: &LateContext<'_>, pat: &'_ rustc_hir::Pat<'_>) { if in_external_macro(cx.sess(), pat.span) { @@ -56,71 +81,83 @@ impl LateLintPass<'_> for ManualRangePatterns { } // a pattern like 1 | 2 seems fine, lint if there are at least 3 alternatives + // or at least one range if let PatKind::Or(pats) = pat.kind - && pats.len() >= 3 + && (pats.len() >= 3 || pats.iter().any(|p| matches!(p.kind, PatKind::Range(..)))) { - let mut min = i128::MAX; - let mut max = i128::MIN; + let mut min = Num::dummy(i128::MAX); + let mut max = Num::dummy(i128::MIN); + let mut range_kind = RangeEnd::Included; let mut numbers_found = FxHashSet::default(); let mut ranges_found = Vec::new(); for pat in pats { if let PatKind::Lit(lit) = pat.kind - && let Some(num) = expr_as_i128(lit) + && let Some(num) = Num::new(lit) { - numbers_found.insert(num); + numbers_found.insert(num.val); min = min.min(num); - max = max.max(num); + if num.val >= max.val { + max = num; + range_kind = RangeEnd::Included; + } } else if let PatKind::Range(Some(left), Some(right), end) = pat.kind - && let Some(left) = expr_as_i128(left) - && let Some(right) = expr_as_i128(right) - && right >= left + && let Some(left) = Num::new(left) + && let Some(mut right) = Num::new(right) { + if let RangeEnd::Excluded = end { + right.val -= 1; + } + min = min.min(left); - max = max.max(right); - ranges_found.push(left..=match end { - RangeEnd::Included => right, - RangeEnd::Excluded => right - 1, - }); + if right.val > max.val { + max = right; + range_kind = end; + } + ranges_found.push(left.val..=right.val); } else { return; } } - let contains_whole_range = 'contains: { - let mut num = min; - while num <= max { - if numbers_found.contains(&num) { - num += 1; - } - // Given a list of (potentially overlapping) ranges like: - // 1..=5, 3..=7, 6..=10 - // We want to find the range with the highest end that still contains the current number - else if let Some(range) = ranges_found - .iter() - .filter(|range| range.contains(&num)) - .max_by_key(|range| range.end()) - { - num = range.end() + 1; - } else { - break 'contains false; - } + let mut num = min.val; + while num <= max.val { + if numbers_found.contains(&num) { + num += 1; + } + // Given a list of (potentially overlapping) ranges like: + // 1..=5, 3..=7, 6..=10 + // We want to find the range with the highest end that still contains the current number + else if let Some(range) = ranges_found + .iter() + .filter(|range| range.contains(&num)) + .max_by_key(|range| range.end()) + { + num = range.end() + 1; + } else { + return; } - break 'contains true; - }; - - if contains_whole_range { - span_lint_and_sugg( - cx, - MANUAL_RANGE_PATTERNS, - pat.span, - "this OR pattern can be rewritten using a range", - "try", - format!("{min}..={max}"), - Applicability::MachineApplicable, - ); } + + span_lint_and_then( + cx, + MANUAL_RANGE_PATTERNS, + pat.span, + "this OR pattern can be rewritten using a range", + |diag| { + if let Some(min) = snippet_opt(cx, min.span) + && let Some(max) = snippet_opt(cx, max.span) + { + diag.span_suggestion( + pat.span, + "try", + format!("{min}{range_kind}{max}"), + Applicability::MachineApplicable, + ); + } + }, + ); } } } diff --git a/clippy_lints/src/methods/iter_out_of_bounds.rs b/clippy_lints/src/methods/iter_out_of_bounds.rs new file mode 100644 index 00000000000..79c6d63254b --- /dev/null +++ b/clippy_lints/src/methods/iter_out_of_bounds.rs @@ -0,0 +1,106 @@ +use clippy_utils::diagnostics::span_lint_and_note; +use clippy_utils::higher::VecArgs; +use clippy_utils::{expr_or_init, is_trait_method, match_def_path, paths}; +use rustc_ast::LitKind; +use rustc_hir::{Expr, ExprKind}; +use rustc_lint::LateContext; +use rustc_middle::ty::{self}; +use rustc_span::sym; + +use super::ITER_OUT_OF_BOUNDS; + +fn expr_as_u128(cx: &LateContext<'_>, e: &Expr<'_>) -> Option<u128> { + if let ExprKind::Lit(lit) = expr_or_init(cx, e).kind + && let LitKind::Int(n, _) = lit.node + { + Some(n) + } else { + None + } +} + +/// Attempts to extract the length out of an iterator expression. +fn get_iterator_length<'tcx>(cx: &LateContext<'tcx>, iter: &'tcx Expr<'tcx>) -> Option<u128> { + let ty::Adt(adt, substs) = cx.typeck_results().expr_ty(iter).kind() else { + return None; + }; + let did = adt.did(); + + if match_def_path(cx, did, &paths::ARRAY_INTO_ITER) { + // For array::IntoIter<T, const N: usize>, the length is the second generic + // parameter. + substs + .const_at(1) + .try_eval_target_usize(cx.tcx, cx.param_env) + .map(u128::from) + } else if match_def_path(cx, did, &paths::SLICE_ITER) + && let ExprKind::MethodCall(_, recv, ..) = iter.kind + { + if let ty::Array(_, len) = cx.typeck_results().expr_ty(recv).peel_refs().kind() { + // For slice::Iter<'_, T>, the receiver might be an array literal: [1,2,3].iter().skip(..) + len.try_eval_target_usize(cx.tcx, cx.param_env).map(u128::from) + } else if let Some(args) = VecArgs::hir(cx, expr_or_init(cx, recv)) { + match args { + VecArgs::Vec(vec) => vec.len().try_into().ok(), + VecArgs::Repeat(_, len) => expr_as_u128(cx, len), + } + } else { + None + } + } else if match_def_path(cx, did, &paths::ITER_EMPTY) { + Some(0) + } else if match_def_path(cx, did, &paths::ITER_ONCE) { + Some(1) + } else { + None + } +} + +fn check<'tcx>( + cx: &LateContext<'tcx>, + expr: &'tcx Expr<'tcx>, + recv: &'tcx Expr<'tcx>, + arg: &'tcx Expr<'tcx>, + message: &'static str, + note: &'static str, +) { + if is_trait_method(cx, expr, sym::Iterator) + && let Some(len) = get_iterator_length(cx, recv) + && let Some(skipped) = expr_as_u128(cx, arg) + && skipped > len + { + span_lint_and_note(cx, ITER_OUT_OF_BOUNDS, expr.span, message, None, note); + } +} + +pub(super) fn check_skip<'tcx>( + cx: &LateContext<'tcx>, + expr: &'tcx Expr<'tcx>, + recv: &'tcx Expr<'tcx>, + arg: &'tcx Expr<'tcx>, +) { + check( + cx, + expr, + recv, + arg, + "this `.skip()` call skips more items than the iterator will produce", + "this operation is useless and will create an empty iterator", + ); +} + +pub(super) fn check_take<'tcx>( + cx: &LateContext<'tcx>, + expr: &'tcx Expr<'tcx>, + recv: &'tcx Expr<'tcx>, + arg: &'tcx Expr<'tcx>, +) { + check( + cx, + expr, + recv, + arg, + "this `.take()` call takes more items than the iterator will produce", + "this operation is useless and the returned iterator will simply yield the same items", + ); +} diff --git a/clippy_lints/src/methods/iter_overeager_cloned.rs b/clippy_lints/src/methods/iter_overeager_cloned.rs index ee405a3e30c..a49dd98db87 100644 --- a/clippy_lints/src/methods/iter_overeager_cloned.rs +++ b/clippy_lints/src/methods/iter_overeager_cloned.rs @@ -21,7 +21,7 @@ pub(super) enum Op<'a> { RmCloned, // rm `.cloned()` - // e.g. `map` `for_each` + // e.g. `map` `for_each` `all` `any` NeedlessMove(&'a str, &'a Expr<'a>), // later `.cloned()` diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index 5075137caa0..81223fa8d95 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -43,6 +43,7 @@ mod iter_next_slice; mod iter_nth; mod iter_nth_zero; mod iter_on_single_or_empty_collections; +mod iter_out_of_bounds; mod iter_overeager_cloned; mod iter_skip_next; mod iter_skip_zero; @@ -3054,12 +3055,12 @@ declare_clippy_lint! { /// /// ### Example /// ```rust - /// vec!(1, 2, 3, 4, 5).resize(0, 5) + /// vec![1, 2, 3, 4, 5].resize(0, 5) /// ``` /// /// Use instead: /// ```rust - /// vec!(1, 2, 3, 4, 5).clear() + /// vec![1, 2, 3, 4, 5].clear() /// ``` #[clippy::version = "1.46.0"] pub VEC_RESIZE_TO_ZERO, @@ -3538,6 +3539,30 @@ declare_clippy_lint! { "acquiring a write lock when a read lock would work" } +declare_clippy_lint! { + /// ### What it does + /// Looks for iterator combinator calls such as `.take(x)` or `.skip(x)` + /// where `x` is greater than the amount of items that an iterator will produce. + /// + /// ### Why is this bad? + /// Taking or skipping more items than there are in an iterator either creates an iterator + /// with all items from the original iterator or an iterator with no items at all. + /// This is most likely not what the user intended to do. + /// + /// ### Example + /// ```rust + /// for _ in [1, 2, 3].iter().take(4) {} + /// ``` + /// Use instead: + /// ```rust + /// for _ in [1, 2, 3].iter() {} + /// ``` + #[clippy::version = "1.74.0"] + pub ITER_OUT_OF_BOUNDS, + suspicious, + "calls to `.take()` or `.skip()` that are out of bounds" +} + pub struct Methods { avoid_breaking_exported_api: bool, msrv: Msrv, @@ -3676,7 +3701,8 @@ impl_lint_pass!(Methods => [ STRING_LIT_CHARS_ANY, ITER_SKIP_ZERO, FILTER_MAP_BOOL_THEN, - READONLY_WRITE_LOCK + READONLY_WRITE_LOCK, + ITER_OUT_OF_BOUNDS, ]); /// Extracts a method call name, args, and `Span` of the method name. @@ -3873,6 +3899,12 @@ impl Methods { ("add" | "offset" | "sub" | "wrapping_offset" | "wrapping_add" | "wrapping_sub", [_arg]) => { zst_offset::check(cx, expr, recv); }, + ("all", [arg]) => { + if let Some(("cloned", recv2, [], _, _)) = method_call(recv) { + iter_overeager_cloned::check(cx, expr, recv, recv2, + iter_overeager_cloned::Op::NeedlessMove(name, arg), false); + } + } ("and_then", [arg]) => { let biom_option_linted = bind_instead_of_map::OptionAndThenSome::check(cx, expr, recv, arg); let biom_result_linted = bind_instead_of_map::ResultAndThenOk::check(cx, expr, recv, arg); @@ -3880,12 +3912,16 @@ impl Methods { unnecessary_lazy_eval::check(cx, expr, recv, arg, "and"); } }, - ("any", [arg]) if let ExprKind::Closure(arg) = arg.kind - && let body = cx.tcx.hir().body(arg.body) - && let [param] = body.params - && let Some(("chars", recv, _, _, _)) = method_call(recv) => - { - string_lit_chars_any::check(cx, expr, recv, param, peel_blocks(body.value), &self.msrv); + ("any", [arg]) => { + match method_call(recv) { + Some(("cloned", recv2, [], _, _)) => iter_overeager_cloned::check(cx, expr, recv, recv2, iter_overeager_cloned::Op::NeedlessMove(name, arg), false), + Some(("chars", recv, _, _, _)) if let ExprKind::Closure(arg) = arg.kind + && let body = cx.tcx.hir().body(arg.body) + && let [param] = body.params => { + string_lit_chars_any::check(cx, expr, recv, param, peel_blocks(body.value), &self.msrv); + } + _ => {} + } } ("arg", [arg]) => { suspicious_command_arg_space::check(cx, recv, arg, span); @@ -4136,6 +4172,7 @@ impl Methods { }, ("skip", [arg]) => { iter_skip_zero::check(cx, expr, arg); + iter_out_of_bounds::check_skip(cx, expr, recv, arg); if let Some(("cloned", recv2, [], _span2, _)) = method_call(recv) { iter_overeager_cloned::check(cx, expr, recv, recv2, @@ -4163,7 +4200,8 @@ impl Methods { } }, ("step_by", [arg]) => iterator_step_by_zero::check(cx, expr, arg), - ("take", [_arg]) => { + ("take", [arg]) => { + iter_out_of_bounds::check_take(cx, expr, recv, arg); if let Some(("cloned", recv2, [], _span2, _)) = method_call(recv) { iter_overeager_cloned::check(cx, expr, recv, recv2, iter_overeager_cloned::Op::LaterCloned, false); diff --git a/clippy_lints/src/missing_asserts_for_indexing.rs b/clippy_lints/src/missing_asserts_for_indexing.rs new file mode 100644 index 00000000000..08fec2b8ec8 --- /dev/null +++ b/clippy_lints/src/missing_asserts_for_indexing.rs @@ -0,0 +1,391 @@ +use std::mem; +use std::ops::ControlFlow; + +use clippy_utils::comparisons::{normalize_comparison, Rel}; +use clippy_utils::diagnostics::span_lint_and_then; +use clippy_utils::source::snippet; +use clippy_utils::visitors::for_each_expr; +use clippy_utils::{eq_expr_value, hash_expr, higher}; +use rustc_ast::{LitKind, RangeLimits}; +use rustc_data_structures::unhash::UnhashMap; +use rustc_errors::{Applicability, Diagnostic}; +use rustc_hir::{BinOp, Block, Expr, ExprKind, UnOp}; +use rustc_lint::{LateContext, LateLintPass}; +use rustc_session::{declare_lint_pass, declare_tool_lint}; +use rustc_span::source_map::Spanned; +use rustc_span::{sym, Span}; + +declare_clippy_lint! { + /// ### What it does + /// Checks for repeated slice indexing without asserting beforehand that the length + /// is greater than the largest index used to index into the slice. + /// + /// ### Why is this bad? + /// In the general case where the compiler does not have a lot of information + /// about the length of a slice, indexing it repeatedly will generate a bounds check + /// for every single index. + /// + /// Asserting that the length of the slice is at least as large as the largest value + /// to index beforehand gives the compiler enough information to elide the bounds checks, + /// effectively reducing the number of bounds checks from however many times + /// the slice was indexed to just one (the assert). + /// + /// ### Drawbacks + /// False positives. It is, in general, very difficult to predict how well + /// the optimizer will be able to elide bounds checks and it very much depends on + /// the surrounding code. For example, indexing into the slice yielded by the + /// [`slice::chunks_exact`](https://doc.rust-lang.org/stable/std/primitive.slice.html#method.chunks_exact) + /// iterator will likely have all of the bounds checks elided even without an assert + /// if the `chunk_size` is a constant. + /// + /// Asserts are not tracked across function calls. Asserting the length of a slice + /// in a different function likely gives the optimizer enough information + /// about the length of a slice, but this lint will not detect that. + /// + /// ### Example + /// ```rust + /// fn sum(v: &[u8]) -> u8 { + /// // 4 bounds checks + /// v[0] + v[1] + v[2] + v[3] + /// } + /// ``` + /// Use instead: + /// ```rust + /// fn sum(v: &[u8]) -> u8 { + /// assert!(v.len() > 4); + /// // no bounds checks + /// v[0] + v[1] + v[2] + v[3] + /// } + /// ``` + #[clippy::version = "1.70.0"] + pub MISSING_ASSERTS_FOR_INDEXING, + restriction, + "indexing into a slice multiple times without an `assert`" +} +declare_lint_pass!(MissingAssertsForIndexing => [MISSING_ASSERTS_FOR_INDEXING]); + +fn report_lint<F>(cx: &LateContext<'_>, full_span: Span, msg: &str, indexes: &[Span], f: F) +where + F: FnOnce(&mut Diagnostic), +{ + span_lint_and_then(cx, MISSING_ASSERTS_FOR_INDEXING, full_span, msg, |diag| { + f(diag); + for span in indexes { + diag.span_note(*span, "slice indexed here"); + } + diag.note("asserting the length before indexing will elide bounds checks"); + }); +} + +#[derive(Copy, Clone, Debug)] +enum LengthComparison { + /// `v.len() < 5` + LengthLessThanInt, + /// `5 < v.len()` + IntLessThanLength, + /// `v.len() <= 5` + LengthLessThanOrEqualInt, + /// `5 <= v.len()` + IntLessThanOrEqualLength, +} + +/// Extracts parts out of a length comparison expression. +/// +/// E.g. for `v.len() > 5` this returns `Some((LengthComparison::IntLessThanLength, 5, `v.len()`))` +fn len_comparison<'hir>( + bin_op: BinOp, + left: &'hir Expr<'hir>, + right: &'hir Expr<'hir>, +) -> Option<(LengthComparison, usize, &'hir Expr<'hir>)> { + macro_rules! int_lit_pat { + ($id:ident) => { + ExprKind::Lit(Spanned { + node: LitKind::Int($id, _), + .. + }) + }; + } + + // normalize comparison, `v.len() > 4` becomes `4 < v.len()` + // this simplifies the logic a bit + let (op, left, right) = normalize_comparison(bin_op.node, left, right)?; + match (op, &left.kind, &right.kind) { + (Rel::Lt, int_lit_pat!(left), _) => Some((LengthComparison::IntLessThanLength, *left as usize, right)), + (Rel::Lt, _, int_lit_pat!(right)) => Some((LengthComparison::LengthLessThanInt, *right as usize, left)), + (Rel::Le, int_lit_pat!(left), _) => Some((LengthComparison::IntLessThanOrEqualLength, *left as usize, right)), + (Rel::Le, _, int_lit_pat!(right)) => Some((LengthComparison::LengthLessThanOrEqualInt, *right as usize, left)), + _ => None, + } +} + +/// Attempts to extract parts out of an `assert!`-like expression +/// in the form `assert!(some_slice.len() > 5)`. +/// +/// `assert!` has expanded to an if expression at the HIR, so this +/// actually works not just with `assert!` specifically, but anything +/// that has a never type expression in the `then` block (e.g. `panic!`). +fn assert_len_expr<'hir>( + cx: &LateContext<'_>, + expr: &'hir Expr<'hir>, +) -> Option<(LengthComparison, usize, &'hir Expr<'hir>)> { + if let Some(higher::If { cond, then, .. }) = higher::If::hir(expr) + && let ExprKind::Unary(UnOp::Not, condition) = &cond.kind + && let ExprKind::Binary(bin_op, left, right) = &condition.kind + + && let Some((cmp, asserted_len, slice_len)) = len_comparison(*bin_op, left, right) + && let ExprKind::MethodCall(method, recv, ..) = &slice_len.kind + && cx.typeck_results().expr_ty_adjusted(recv).peel_refs().is_slice() + && method.ident.name == sym::len + + // check if `then` block has a never type expression + && let ExprKind::Block(Block { expr: Some(then_expr), .. }, _) = then.kind + && cx.typeck_results().expr_ty(then_expr).is_never() + { + Some((cmp, asserted_len, recv)) + } else { + None + } +} + +#[derive(Debug)] +enum IndexEntry<'hir> { + /// `assert!` without any indexing (so far) + StrayAssert { + asserted_len: usize, + comparison: LengthComparison, + assert_span: Span, + slice: &'hir Expr<'hir>, + }, + /// `assert!` with indexing + /// + /// We also store the highest index to be able to check + /// if the `assert!` asserts the right length. + AssertWithIndex { + highest_index: usize, + asserted_len: usize, + assert_span: Span, + slice: &'hir Expr<'hir>, + indexes: Vec<Span>, + comparison: LengthComparison, + }, + /// Indexing without an `assert!` + IndexWithoutAssert { + highest_index: usize, + indexes: Vec<Span>, + slice: &'hir Expr<'hir>, + }, +} + +impl<'hir> IndexEntry<'hir> { + pub fn slice(&self) -> &'hir Expr<'hir> { + match self { + IndexEntry::StrayAssert { slice, .. } + | IndexEntry::AssertWithIndex { slice, .. } + | IndexEntry::IndexWithoutAssert { slice, .. } => slice, + } + } + + pub fn index_spans(&self) -> Option<&[Span]> { + match self { + IndexEntry::StrayAssert { .. } => None, + IndexEntry::AssertWithIndex { indexes, .. } | IndexEntry::IndexWithoutAssert { indexes, .. } => { + Some(indexes) + }, + } + } +} + +/// Extracts the upper index of a slice indexing expression. +/// +/// E.g. for `5` this returns `Some(5)`, for `..5` this returns `Some(4)`, +/// for `..=5` this returns `Some(5)` +fn upper_index_expr(expr: &Expr<'_>) -> Option<usize> { + if let ExprKind::Lit(lit) = &expr.kind && let LitKind::Int(index, _) = lit.node { + Some(index as usize) + } else if let Some(higher::Range { end: Some(end), limits, .. }) = higher::Range::hir(expr) + && let ExprKind::Lit(lit) = &end.kind + && let LitKind::Int(index @ 1.., _) = lit.node + { + match limits { + RangeLimits::HalfOpen => Some(index as usize - 1), + RangeLimits::Closed => Some(index as usize), + } + } else { + None + } +} + +/// Checks if the expression is an index into a slice and adds it to `indexes` +fn check_index<'hir>(cx: &LateContext<'_>, expr: &'hir Expr<'hir>, map: &mut UnhashMap<u64, Vec<IndexEntry<'hir>>>) { + if let ExprKind::Index(slice, index_lit, _) = expr.kind + && cx.typeck_results().expr_ty_adjusted(slice).peel_refs().is_slice() + && let Some(index) = upper_index_expr(index_lit) + { + let hash = hash_expr(cx, slice); + + let indexes = map.entry(hash).or_default(); + let entry = indexes.iter_mut().find(|entry| eq_expr_value(cx, entry.slice(), slice)); + + if let Some(entry) = entry { + match entry { + IndexEntry::StrayAssert { asserted_len, comparison, assert_span, slice } => { + *entry = IndexEntry::AssertWithIndex { + highest_index: index, + asserted_len: *asserted_len, + assert_span: *assert_span, + slice, + indexes: vec![expr.span], + comparison: *comparison, + }; + }, + IndexEntry::IndexWithoutAssert { highest_index, indexes, .. } + | IndexEntry::AssertWithIndex { highest_index, indexes, .. } => { + indexes.push(expr.span); + *highest_index = (*highest_index).max(index); + }, + } + } else { + indexes.push(IndexEntry::IndexWithoutAssert { + highest_index: index, + indexes: vec![expr.span], + slice, + }); + } + } +} + +/// Checks if the expression is an `assert!` expression and adds it to `asserts` +fn check_assert<'hir>(cx: &LateContext<'_>, expr: &'hir Expr<'hir>, map: &mut UnhashMap<u64, Vec<IndexEntry<'hir>>>) { + if let Some((comparison, asserted_len, slice)) = assert_len_expr(cx, expr) { + let hash = hash_expr(cx, slice); + let indexes = map.entry(hash).or_default(); + + let entry = indexes.iter_mut().find(|entry| eq_expr_value(cx, entry.slice(), slice)); + + if let Some(entry) = entry { + if let IndexEntry::IndexWithoutAssert { + highest_index, + indexes, + slice, + } = entry + { + *entry = IndexEntry::AssertWithIndex { + highest_index: *highest_index, + indexes: mem::take(indexes), + slice, + assert_span: expr.span, + comparison, + asserted_len, + }; + } + } else { + indexes.push(IndexEntry::StrayAssert { + asserted_len, + comparison, + assert_span: expr.span, + slice, + }); + } + } +} + +/// Inspects indexes and reports lints. +/// +/// Called at the end of this lint after all indexing and `assert!` expressions have been collected. +fn report_indexes(cx: &LateContext<'_>, map: &UnhashMap<u64, Vec<IndexEntry<'_>>>) { + for bucket in map.values() { + for entry in bucket { + let Some(full_span) = entry + .index_spans() + .and_then(|spans| spans.first().zip(spans.last())) + .map(|(low, &high)| low.to(high)) + else { + continue; + }; + + match entry { + IndexEntry::AssertWithIndex { + highest_index, + asserted_len, + indexes, + comparison, + assert_span, + slice, + } if indexes.len() > 1 => { + // if we have found an `assert!`, let's also check that it's actually right + // and if it convers the highest index and if not, suggest the correct length + let sugg = match comparison { + // `v.len() < 5` and `v.len() <= 5` does nothing in terms of bounds checks. + // The user probably meant `v.len() > 5` + LengthComparison::LengthLessThanInt | LengthComparison::LengthLessThanOrEqualInt => Some( + format!("assert!({}.len() > {highest_index})", snippet(cx, slice.span, "..")), + ), + // `5 < v.len()` == `v.len() > 5` + LengthComparison::IntLessThanLength if asserted_len < highest_index => Some(format!( + "assert!({}.len() > {highest_index})", + snippet(cx, slice.span, "..") + )), + // `5 <= v.len() == `v.len() >= 5` + LengthComparison::IntLessThanOrEqualLength if asserted_len <= highest_index => Some(format!( + "assert!({}.len() > {highest_index})", + snippet(cx, slice.span, "..") + )), + _ => None, + }; + + if let Some(sugg) = sugg { + report_lint( + cx, + full_span, + "indexing into a slice multiple times with an `assert` that does not cover the highest index", + indexes, + |diag| { + diag.span_suggestion( + *assert_span, + "provide the highest index that is indexed with", + sugg, + Applicability::MachineApplicable, + ); + }, + ); + } + }, + IndexEntry::IndexWithoutAssert { + indexes, + highest_index, + slice, + } if indexes.len() > 1 => { + // if there was no `assert!` but more than one index, suggest + // adding an `assert!` that covers the highest index + report_lint( + cx, + full_span, + "indexing into a slice multiple times without an `assert`", + indexes, + |diag| { + diag.help(format!( + "consider asserting the length before indexing: `assert!({}.len() > {highest_index});`", + snippet(cx, slice.span, "..") + )); + }, + ); + }, + _ => {}, + } + } + } +} + +impl LateLintPass<'_> for MissingAssertsForIndexing { + fn check_block(&mut self, cx: &LateContext<'_>, block: &Block<'_>) { + let mut map = UnhashMap::default(); + + for_each_expr(block, |expr| { + check_index(cx, expr, &mut map); + check_assert(cx, expr, &mut map); + ControlFlow::<!, ()>::Continue(()) + }); + + report_indexes(cx, &map); + } +} diff --git a/clippy_lints/src/incorrect_impls.rs b/clippy_lints/src/non_canonical_impls.rs index 3c59b839a39..4b24f059afd 100644 --- a/clippy_lints/src/incorrect_impls.rs +++ b/clippy_lints/src/non_canonical_impls.rs @@ -13,11 +13,12 @@ use rustc_span::symbol::kw; declare_clippy_lint! { /// ### What it does - /// Checks for manual implementations of `Clone` when `Copy` is already implemented. + /// Checks for non-canonical implementations of `Clone` when `Copy` is already implemented. /// /// ### Why is this bad? - /// If both `Clone` and `Copy` are implemented, they must agree. This is done by dereferencing - /// `self` in `Clone`'s implementation. Anything else is incorrect. + /// If both `Clone` and `Copy` are implemented, they must agree. This can done by dereferencing + /// `self` in `Clone`'s implementation, which will avoid any possibility of the implementations + /// becoming out of sync. /// /// ### Example /// ```rust,ignore @@ -46,14 +47,13 @@ declare_clippy_lint! { /// impl Copy for A {} /// ``` #[clippy::version = "1.72.0"] - pub INCORRECT_CLONE_IMPL_ON_COPY_TYPE, - correctness, - "manual implementation of `Clone` on a `Copy` type" + pub NON_CANONICAL_CLONE_IMPL, + suspicious, + "non-canonical implementation of `Clone` on a `Copy` type" } declare_clippy_lint! { /// ### What it does - /// Checks for manual implementations of both `PartialOrd` and `Ord` when only `Ord` is - /// necessary. + /// Checks for non-canonical implementations of `PartialOrd` when `Ord` is already implemented. /// /// ### Why is this bad? /// If both `PartialOrd` and `Ord` are implemented, they must agree. This is commonly done by @@ -61,11 +61,8 @@ declare_clippy_lint! { /// introduce an error upon refactoring. /// /// ### Known issues - /// Code that calls the `.into()` method instead will be flagged as incorrect, despite `.into()` - /// wrapping it in `Some`. - /// - /// ### Limitations - /// Will not lint if `Self` and `Rhs` do not have the same type. + /// Code that calls the `.into()` method instead will be flagged, despite `.into()` wrapping it + /// in `Some`. /// /// ### Example /// ```rust @@ -107,13 +104,13 @@ declare_clippy_lint! { /// } /// ``` #[clippy::version = "1.72.0"] - pub INCORRECT_PARTIAL_ORD_IMPL_ON_ORD_TYPE, - correctness, - "manual implementation of `PartialOrd` when `Ord` is already implemented" + pub NON_CANONICAL_PARTIAL_ORD_IMPL, + suspicious, + "non-canonical implementation of `PartialOrd` on an `Ord` type" } -declare_lint_pass!(IncorrectImpls => [INCORRECT_CLONE_IMPL_ON_COPY_TYPE, INCORRECT_PARTIAL_ORD_IMPL_ON_ORD_TYPE]); +declare_lint_pass!(NonCanonicalImpls => [NON_CANONICAL_CLONE_IMPL, NON_CANONICAL_PARTIAL_ORD_IMPL]); -impl LateLintPass<'_> for IncorrectImpls { +impl LateLintPass<'_> for NonCanonicalImpls { #[expect(clippy::too_many_lines)] fn check_impl_item(&mut self, cx: &LateContext<'_>, impl_item: &ImplItem<'_>) { let Some(Node::Item(item)) = get_parent_node(cx.tcx, impl_item.hir_id()) else { @@ -154,9 +151,9 @@ impl LateLintPass<'_> for IncorrectImpls { {} else { span_lint_and_sugg( cx, - INCORRECT_CLONE_IMPL_ON_COPY_TYPE, + NON_CANONICAL_CLONE_IMPL, block.span, - "incorrect implementation of `clone` on a `Copy` type", + "non-canonical implementation of `clone` on a `Copy` type", "change this to", "{ *self }".to_owned(), Applicability::MaybeIncorrect, @@ -169,9 +166,9 @@ impl LateLintPass<'_> for IncorrectImpls { if impl_item.ident.name == sym::clone_from { span_lint_and_sugg( cx, - INCORRECT_CLONE_IMPL_ON_COPY_TYPE, + NON_CANONICAL_CLONE_IMPL, impl_item.span, - "incorrect implementation of `clone_from` on a `Copy` type", + "unnecessary implementation of `clone_from` on a `Copy` type", "remove it", String::new(), Applicability::MaybeIncorrect, @@ -222,9 +219,9 @@ impl LateLintPass<'_> for IncorrectImpls { span_lint_and_then( cx, - INCORRECT_PARTIAL_ORD_IMPL_ON_ORD_TYPE, + NON_CANONICAL_PARTIAL_ORD_IMPL, item.span, - "incorrect implementation of `partial_cmp` on an `Ord` type", + "non-canonical implementation of `partial_cmp` on an `Ord` type", |diag| { let [_, other] = body.params else { return; diff --git a/clippy_lints/src/operators/arithmetic_side_effects.rs b/clippy_lints/src/operators/arithmetic_side_effects.rs index a687c7d29b5..8072aded851 100644 --- a/clippy_lints/src/operators/arithmetic_side_effects.rs +++ b/clippy_lints/src/operators/arithmetic_side_effects.rs @@ -14,7 +14,12 @@ use {rustc_ast as ast, rustc_hir as hir}; const HARD_CODED_ALLOWED_BINARY: &[[&str; 2]] = &[["f32", "f32"], ["f64", "f64"], ["std::string::String", "str"]]; const HARD_CODED_ALLOWED_UNARY: &[&str] = &["f32", "f64", "std::num::Saturating", "std::num::Wrapping"]; -const INTEGER_METHODS: &[Symbol] = &[sym::saturating_div, sym::wrapping_div, sym::wrapping_rem, sym::wrapping_rem_euclid]; +const INTEGER_METHODS: &[Symbol] = &[ + sym::saturating_div, + sym::wrapping_div, + sym::wrapping_rem, + sym::wrapping_rem_euclid, +]; #[derive(Debug)] pub struct ArithmeticSideEffects { @@ -93,7 +98,14 @@ impl ArithmeticSideEffects { let is_non_zero_u = |symbol: Option<Symbol>| { matches!( symbol, - Some(sym::NonZeroU128 | sym::NonZeroU16 | sym::NonZeroU32 | sym::NonZeroU64 | sym::NonZeroU8 | sym::NonZeroUsize) + Some( + sym::NonZeroU128 + | sym::NonZeroU16 + | sym::NonZeroU32 + | sym::NonZeroU64 + | sym::NonZeroU8 + | sym::NonZeroUsize + ) ) }; let is_sat_or_wrap = |ty: Ty<'_>| { diff --git a/clippy_lints/src/operators/float_cmp.rs b/clippy_lints/src/operators/float_cmp.rs index f3e0c58a787..bce6bdcaf61 100644 --- a/clippy_lints/src/operators/float_cmp.rs +++ b/clippy_lints/src/operators/float_cmp.rs @@ -17,7 +17,7 @@ pub(crate) fn check<'tcx>( left: &'tcx Expr<'_>, right: &'tcx Expr<'_>, ) { - if (op == BinOpKind::Eq || op == BinOpKind::Ne) && (is_float(cx, left) || is_float(cx, right)) { + if (op == BinOpKind::Eq || op == BinOpKind::Ne) && is_float(cx, left) { let left_is_local = match constant_with_source(cx, cx.typeck_results(), left) { Some((c, s)) if !is_allowed(&c) => s.is_local(), Some(_) => return, diff --git a/clippy_lints/src/raw_strings.rs b/clippy_lints/src/raw_strings.rs index ccabb577cb7..e8018462d75 100644 --- a/clippy_lints/src/raw_strings.rs +++ b/clippy_lints/src/raw_strings.rs @@ -1,7 +1,7 @@ use std::iter::once; use std::ops::ControlFlow; -use clippy_utils::diagnostics::span_lint_and_sugg; +use clippy_utils::diagnostics::span_lint_and_then; use clippy_utils::source::snippet; use rustc_ast::ast::{Expr, ExprKind}; use rustc_ast::token::LitKind; @@ -9,6 +9,7 @@ use rustc_errors::Applicability; use rustc_lint::{EarlyContext, EarlyLintPass, LintContext}; use rustc_middle::lint::in_external_macro; use rustc_session::{declare_tool_lint, impl_lint_pass}; +use rustc_span::{BytePos, Pos, Span}; declare_clippy_lint! { /// ### What it does @@ -76,14 +77,33 @@ impl EarlyLintPass for RawStrings { } if !str.contains(['\\', '"']) { - span_lint_and_sugg( + span_lint_and_then( cx, NEEDLESS_RAW_STRINGS, expr.span, "unnecessary raw string literal", - "try", - format!("{}\"{}\"", prefix.replace('r', ""), lit.symbol), - Applicability::MachineApplicable, + |diag| { + let (start, end) = hash_spans(expr.span, prefix, 0, max); + + // BytePos: skip over the `b` in `br`, we checked the prefix appears in the source text + let r_pos = expr.span.lo() + BytePos::from_usize(prefix.len() - 1); + let start = start.with_lo(r_pos); + + if end.is_empty() { + diag.span_suggestion( + start, + "use a string literal instead", + format!("\"{}\"", str), + Applicability::MachineApplicable, + ); + } else { + diag.multipart_suggestion( + "try", + vec![(start, String::new()), (end, String::new())], + Applicability::MachineApplicable, + ); + } + }, ); return; @@ -96,13 +116,6 @@ impl EarlyLintPass for RawStrings { let num = str.as_bytes().iter().chain(once(&0)).try_fold(0u8, |acc, &b| { match b { b'"' if !following_quote => (following_quote, req) = (true, 1), - // I'm a bit surprised the compiler didn't optimize this out, there's no - // branch but it still ends up doing an unnecessary comparison, it's: - // - cmp r9b,1h - // - sbb cl,-1h - // which will add 1 if it's true. With this change, it becomes: - // - add cl,r9b - // isn't that so much nicer? b'#' => req += u8::from(following_quote), _ => { if following_quote { @@ -126,18 +139,58 @@ impl EarlyLintPass for RawStrings { }; if req < max { - let hashes = "#".repeat(req as usize); - - span_lint_and_sugg( + span_lint_and_then( cx, NEEDLESS_RAW_STRING_HASHES, expr.span, "unnecessary hashes around raw string literal", - "try", - format!(r#"{prefix}{hashes}"{}"{hashes}"#, lit.symbol), - Applicability::MachineApplicable, + |diag| { + let (start, end) = hash_spans(expr.span, prefix, req, max); + + let message = match max - req { + _ if req == 0 => "remove all the hashes around the literal".to_string(), + 1 => "remove one hash from both sides of the literal".to_string(), + n => format!("remove {n} hashes from both sides of the literal"), + }; + + diag.multipart_suggestion( + message, + vec![(start, String::new()), (end, String::new())], + Applicability::MachineApplicable, + ); + }, ); } } } } + +/// Returns spans pointing at the unneeded hashes, e.g. for a `req` of `1` and `max` of `3`: +/// +/// ```ignore +/// r###".."### +/// ^^ ^^ +/// ``` +fn hash_spans(literal_span: Span, prefix: &str, req: u8, max: u8) -> (Span, Span) { + let literal_span = literal_span.data(); + + // BytePos: we checked prefix appears literally in the source text + let hash_start = literal_span.lo + BytePos::from_usize(prefix.len()); + let hash_end = literal_span.hi; + + // BytePos: req/max are counts of the ASCII character # + let start = Span::new( + hash_start + BytePos(req.into()), + hash_start + BytePos(max.into()), + literal_span.ctxt, + None, + ); + let end = Span::new( + hash_end - BytePos(req.into()), + hash_end - BytePos(max.into()), + literal_span.ctxt, + None, + ); + + (start, end) +} diff --git a/clippy_lints/src/renamed_lints.rs b/clippy_lints/src/renamed_lints.rs index fc1fabcc0ae..613f1ecc6fb 100644 --- a/clippy_lints/src/renamed_lints.rs +++ b/clippy_lints/src/renamed_lints.rs @@ -15,6 +15,8 @@ pub static RENAMED_LINTS: &[(&str, &str)] = &[ ("clippy::eval_order_dependence", "clippy::mixed_read_write_in_expression"), ("clippy::identity_conversion", "clippy::useless_conversion"), ("clippy::if_let_some_result", "clippy::match_result_ok"), + ("clippy::incorrect_clone_impl_on_copy_type", "clippy::non_canonical_clone_impl"), + ("clippy::incorrect_partial_ord_impl_on_ord_type", "clippy::non_canonical_partial_ord_impl"), ("clippy::integer_arithmetic", "clippy::arithmetic_side_effects"), ("clippy::logic_bug", "clippy::overly_complex_bool_expr"), ("clippy::new_without_default_derive", "clippy::new_without_default"), @@ -38,12 +40,12 @@ pub static RENAMED_LINTS: &[(&str, &str)] = &[ ("clippy::drop_bounds", "drop_bounds"), ("clippy::drop_copy", "dropping_copy_types"), ("clippy::drop_ref", "dropping_references"), + ("clippy::fn_null_check", "useless_ptr_null_checks"), ("clippy::for_loop_over_option", "for_loops_over_fallibles"), ("clippy::for_loop_over_result", "for_loops_over_fallibles"), ("clippy::for_loops_over_fallibles", "for_loops_over_fallibles"), ("clippy::forget_copy", "forgetting_copy_types"), ("clippy::forget_ref", "forgetting_references"), - ("clippy::fn_null_check", "useless_ptr_null_checks"), ("clippy::into_iter_on_array", "array_into_iter"), ("clippy::invalid_atomic_ordering", "invalid_atomic_ordering"), ("clippy::invalid_ref", "invalid_value"), diff --git a/clippy_lints/src/slow_vector_initialization.rs b/clippy_lints/src/slow_vector_initialization.rs index c9ab622ad25..9db18c2976c 100644 --- a/clippy_lints/src/slow_vector_initialization.rs +++ b/clippy_lints/src/slow_vector_initialization.rs @@ -1,4 +1,5 @@ use clippy_utils::diagnostics::span_lint_and_then; +use clippy_utils::macros::root_macro_call; use clippy_utils::sugg::Sugg; use clippy_utils::{ get_enclosing_block, is_expr_path_def_path, is_integer_literal, is_path_diagnostic_item, path_to_local, @@ -148,6 +149,15 @@ impl SlowVectorInit { /// - `Some(InitializedSize::Uninitialized)` for `Vec::new()` /// - `None` for other, unrelated kinds of expressions fn as_vec_initializer<'tcx>(cx: &LateContext<'_>, expr: &'tcx Expr<'tcx>) -> Option<InitializedSize<'tcx>> { + // Generally don't warn if the vec initializer comes from an expansion, except for the vec! macro. + // This lets us still warn on `vec![]`, while ignoring other kinds of macros that may output an + // empty vec + if expr.span.from_expansion() + && root_macro_call(expr.span).map(|m| m.def_id) != cx.tcx.get_diagnostic_item(sym::vec_macro) + { + return None; + } + if let ExprKind::Call(func, [len_expr]) = expr.kind && is_expr_path_def_path(cx, func, &paths::VEC_WITH_CAPACITY) { @@ -205,7 +215,7 @@ impl SlowVectorInit { span_lint_and_then(cx, SLOW_VECTOR_INITIALIZATION, slow_fill.span, msg, |diag| { diag.span_suggestion( - vec_alloc.allocation_expr.span, + vec_alloc.allocation_expr.span.source_callsite(), "consider replacing this with", format!("vec![0; {len_expr}]"), Applicability::Unspecified, diff --git a/clippy_lints/src/std_instead_of_core.rs b/clippy_lints/src/std_instead_of_core.rs index f239165276f..5f54a10d1c4 100644 --- a/clippy_lints/src/std_instead_of_core.rs +++ b/clippy_lints/src/std_instead_of_core.rs @@ -1,4 +1,5 @@ -use clippy_utils::diagnostics::span_lint_and_help; +use clippy_utils::diagnostics::span_lint_and_sugg; +use rustc_errors::Applicability; use rustc_hir::def::Res; use rustc_hir::def_id::DefId; use rustc_hir::{HirId, Path, PathSegment}; @@ -99,17 +100,17 @@ impl<'tcx> LateLintPass<'tcx> for StdReexports { && let Some(first_segment) = get_first_segment(path) && is_stable(cx, def_id) { - let (lint, msg, help) = match first_segment.ident.name { + let (lint, used_mod, replace_with) = match first_segment.ident.name { sym::std => match cx.tcx.crate_name(def_id.krate) { sym::core => ( STD_INSTEAD_OF_CORE, - "used import from `std` instead of `core`", - "consider importing the item from `core`", + "std", + "core", ), sym::alloc => ( STD_INSTEAD_OF_ALLOC, - "used import from `std` instead of `alloc`", - "consider importing the item from `alloc`", + "std", + "alloc", ), _ => { self.prev_span = path.span; @@ -120,8 +121,8 @@ impl<'tcx> LateLintPass<'tcx> for StdReexports { if cx.tcx.crate_name(def_id.krate) == sym::core { ( ALLOC_INSTEAD_OF_CORE, - "used import from `alloc` instead of `core`", - "consider importing the item from `core`", + "alloc", + "core", ) } else { self.prev_span = path.span; @@ -131,7 +132,14 @@ impl<'tcx> LateLintPass<'tcx> for StdReexports { _ => return, }; if path.span != self.prev_span { - span_lint_and_help(cx, lint, path.span, msg, None, help); + span_lint_and_sugg( + cx, + lint, + first_segment.ident.span, + &format!("used import from `{used_mod}` instead of `{replace_with}`"), + &format!("consider importing the item from `{replace_with}`"), + replace_with.to_string(), + Applicability::MachineApplicable); self.prev_span = path.span; } } diff --git a/clippy_lints/src/undocumented_unsafe_blocks.rs b/clippy_lints/src/undocumented_unsafe_blocks.rs index da8d8ed4c0f..6193fdeb433 100644 --- a/clippy_lints/src/undocumented_unsafe_blocks.rs +++ b/clippy_lints/src/undocumented_unsafe_blocks.rs @@ -341,44 +341,21 @@ fn block_parents_have_safety_comment( id: hir::HirId, ) -> bool { if let Some(node) = get_parent_node(cx.tcx, id) { - return match node { - Node::Expr(expr) => { - if let Some( - Node::Local(hir::Local { span, .. }) - | Node::Item(hir::Item { - kind: hir::ItemKind::Const(..) | ItemKind::Static(..), - span, - .. - }), - ) = get_parent_node(cx.tcx, expr.hir_id) - { - let hir_id = match get_parent_node(cx.tcx, expr.hir_id) { - Some(Node::Local(hir::Local { hir_id, .. })) => *hir_id, - Some(Node::Item(hir::Item { owner_id, .. })) => { - cx.tcx.hir().local_def_id_to_hir_id(owner_id.def_id) - }, - _ => unreachable!(), - }; - - // if unsafe block is part of a let/const/static statement, - // and accept_comment_above_statement is set to true - // we accept the safety comment in the line the precedes this statement. - accept_comment_above_statement - && span_with_attrs_in_body_has_safety_comment( - cx, - *span, - hir_id, - accept_comment_above_attributes, - ) - } else { - !is_branchy(expr) - && span_with_attrs_in_body_has_safety_comment( - cx, - expr.span, - expr.hir_id, - accept_comment_above_attributes, - ) - } + let (span, hir_id) = match node { + Node::Expr(expr) => match get_parent_node(cx.tcx, expr.hir_id) { + Some(Node::Local(hir::Local { span, hir_id, .. })) => (*span, *hir_id), + Some(Node::Item(hir::Item { + kind: hir::ItemKind::Const(..) | ItemKind::Static(..), + span, + owner_id, + .. + })) => (*span, cx.tcx.hir().local_def_id_to_hir_id(owner_id.def_id)), + _ => { + if is_branchy(expr) { + return false; + } + (expr.span, expr.hir_id) + }, }, Node::Stmt(hir::Stmt { kind: @@ -387,28 +364,27 @@ fn block_parents_have_safety_comment( | hir::StmtKind::Semi(hir::Expr { span, hir_id, .. }), .. }) - | Node::Local(hir::Local { span, hir_id, .. }) => { - span_with_attrs_in_body_has_safety_comment(cx, *span, *hir_id, accept_comment_above_attributes) - }, + | Node::Local(hir::Local { span, hir_id, .. }) => (*span, *hir_id), Node::Item(hir::Item { kind: hir::ItemKind::Const(..) | ItemKind::Static(..), span, owner_id, .. - }) => span_with_attrs_in_body_has_safety_comment( - cx, - *span, - cx.tcx.hir().local_def_id_to_hir_id(owner_id.def_id), - accept_comment_above_attributes, - ), - _ => false, + }) => (*span, cx.tcx.hir().local_def_id_to_hir_id(owner_id.def_id)), + _ => return false, }; + // if unsafe block is part of a let/const/static statement, + // and accept_comment_above_statement is set to true + // we accept the safety comment in the line the precedes this statement. + accept_comment_above_statement + && span_with_attrs_has_safety_comment(cx, span, hir_id, accept_comment_above_attributes) + } else { + false } - false } /// Extends `span` to also include its attributes, then checks if that span has a safety comment. -fn span_with_attrs_in_body_has_safety_comment( +fn span_with_attrs_has_safety_comment( cx: &LateContext<'_>, span: Span, hir_id: HirId, @@ -420,7 +396,7 @@ fn span_with_attrs_in_body_has_safety_comment( span }; - span_in_body_has_safety_comment(cx, span) + span_has_safety_comment(cx, span) } /// Checks if an expression is "branchy", e.g. loop, match/if/etc. @@ -444,7 +420,7 @@ fn block_has_safety_comment(cx: &LateContext<'_>, span: Span) -> bool { matches!( span_from_macro_expansion_has_safety_comment(cx, span), HasSafetyComment::Yes(_) - ) || span_in_body_has_safety_comment(cx, span) + ) || span_has_safety_comment(cx, span) } fn include_attrs_in_span(cx: &LateContext<'_>, hir_id: HirId, span: Span) -> Span { @@ -633,29 +609,36 @@ fn get_body_search_span(cx: &LateContext<'_>) -> Option<Span> { let body = cx.enclosing_body?; let map = cx.tcx.hir(); let mut span = map.body(body).value.span; + let mut maybe_global_var = false; for (_, node) in map.parent_iter(body.hir_id) { match node { Node::Expr(e) => span = e.span, - Node::Block(_) - | Node::Arm(_) - | Node::Stmt(_) - | Node::Local(_) - | Node::Item(hir::Item { + Node::Block(_) | Node::Arm(_) | Node::Stmt(_) | Node::Local(_) => (), + Node::Item(hir::Item { kind: hir::ItemKind::Const(..) | ItemKind::Static(..), .. - }) => (), + }) => maybe_global_var = true, + Node::Item(hir::Item { + kind: hir::ItemKind::Mod(_), + span: item_span, + .. + }) => { + span = *item_span; + break; + }, + Node::Crate(mod_) if maybe_global_var => { + span = mod_.spans.inner_span; + }, _ => break, } } Some(span) } -fn span_in_body_has_safety_comment(cx: &LateContext<'_>, span: Span) -> bool { +fn span_has_safety_comment(cx: &LateContext<'_>, span: Span) -> bool { let source_map = cx.sess().source_map(); let ctxt = span.ctxt(); - if ctxt == SyntaxContext::root() - && let Some(search_span) = get_body_search_span(cx) - { + if ctxt.is_root() && let Some(search_span) = get_body_search_span(cx) { if let Ok(unsafe_line) = source_map.lookup_line(span.lo()) && let Some(body_span) = walk_span_to_context(search_span, SyntaxContext::root()) && let Ok(body_line) = source_map.lookup_line(body_span.lo()) diff --git a/clippy_lints/src/unit_return_expecting_ord.rs b/clippy_lints/src/unit_return_expecting_ord.rs index dd829ded0d0..de4b8738e35 100644 --- a/clippy_lints/src/unit_return_expecting_ord.rs +++ b/clippy_lints/src/unit_return_expecting_ord.rs @@ -26,7 +26,7 @@ declare_clippy_lint! { /// /// ### Example /// ```rust - /// let mut twins = vec!((1, 1), (2, 2)); + /// let mut twins = vec![(1, 1), (2, 2)]; /// twins.sort_by_key(|x| { x.1; }); /// ``` #[clippy::version = "1.47.0"] diff --git a/clippy_lints/src/unwrap.rs b/clippy_lints/src/unwrap.rs index c99b0290c0c..9a0d83d83f1 100644 --- a/clippy_lints/src/unwrap.rs +++ b/clippy_lints/src/unwrap.rs @@ -1,15 +1,18 @@ use clippy_utils::diagnostics::span_lint_hir_and_then; use clippy_utils::ty::is_type_diagnostic_item; -use clippy_utils::usage::is_potentially_mutated; +use clippy_utils::usage::is_potentially_local_place; use clippy_utils::{higher, path_to_local}; use if_chain::if_chain; use rustc_errors::Applicability; use rustc_hir::intravisit::{walk_expr, walk_fn, FnKind, Visitor}; -use rustc_hir::{BinOpKind, Body, Expr, ExprKind, FnDecl, HirId, PathSegment, UnOp}; +use rustc_hir::{BinOpKind, Body, Expr, ExprKind, FnDecl, HirId, Node, PathSegment, UnOp}; +use rustc_hir_typeck::expr_use_visitor::{Delegate, ExprUseVisitor, PlaceWithHirId}; +use rustc_infer::infer::TyCtxtInferExt; use rustc_lint::{LateContext, LateLintPass}; use rustc_middle::hir::nested_filter; use rustc_middle::lint::in_external_macro; -use rustc_middle::ty::Ty; +use rustc_middle::mir::FakeReadCause; +use rustc_middle::ty::{self, Ty, TyCtxt}; use rustc_session::{declare_lint_pass, declare_tool_lint}; use rustc_span::def_id::LocalDefId; use rustc_span::source_map::Span; @@ -192,6 +195,55 @@ fn collect_unwrap_info<'tcx>( Vec::new() } +/// A HIR visitor delegate that checks if a local variable of type `Option<_>` is mutated, +/// *except* for if `Option::as_mut` is called. +/// The reason for why we allow that one specifically is that `.as_mut()` cannot change +/// the option to `None`, and that is important because this lint relies on the fact that +/// `is_some` + `unwrap` is equivalent to `if let Some(..) = ..`, which it would not be if +/// the option is changed to None between `is_some` and `unwrap`. +/// (And also `.as_mut()` is a somewhat common method that is still worth linting on.) +struct MutationVisitor<'tcx> { + is_mutated: bool, + local_id: HirId, + tcx: TyCtxt<'tcx>, +} + +/// Checks if the parent of the expression pointed at by the given `HirId` is a call to +/// `Option::as_mut`. +/// +/// Used by the mutation visitor to specifically allow `.as_mut()` calls. +/// In particular, the `HirId` that the visitor receives is the id of the local expression +/// (i.e. the `x` in `x.as_mut()`), and that is the reason for why we care about its parent +/// expression: that will be where the actual method call is. +fn is_option_as_mut_use(tcx: TyCtxt<'_>, expr_id: HirId) -> bool { + if let Node::Expr(mutating_expr) = tcx.hir().get_parent(expr_id) + && let ExprKind::MethodCall(path, ..) = mutating_expr.kind + { + path.ident.name.as_str() == "as_mut" + } else { + false + } +} + +impl<'tcx> Delegate<'tcx> for MutationVisitor<'tcx> { + fn borrow(&mut self, cat: &PlaceWithHirId<'tcx>, diag_expr_id: HirId, bk: ty::BorrowKind) { + if let ty::BorrowKind::MutBorrow = bk + && is_potentially_local_place(self.local_id, &cat.place) + && !is_option_as_mut_use(self.tcx, diag_expr_id) + { + self.is_mutated = true; + } + } + + fn mutate(&mut self, _: &PlaceWithHirId<'tcx>, _: HirId) { + self.is_mutated = true; + } + + fn consume(&mut self, _: &PlaceWithHirId<'tcx>, _: HirId) {} + + fn fake_read(&mut self, _: &PlaceWithHirId<'tcx>, _: FakeReadCause, _: HirId) {} +} + impl<'a, 'tcx> UnwrappableVariablesVisitor<'a, 'tcx> { fn visit_branch( &mut self, @@ -202,10 +254,26 @@ impl<'a, 'tcx> UnwrappableVariablesVisitor<'a, 'tcx> { ) { let prev_len = self.unwrappables.len(); for unwrap_info in collect_unwrap_info(self.cx, if_expr, cond, branch, else_branch, true) { - if is_potentially_mutated(unwrap_info.local_id, cond, self.cx) - || is_potentially_mutated(unwrap_info.local_id, branch, self.cx) - { - // if the variable is mutated, we don't know whether it can be unwrapped: + let mut delegate = MutationVisitor { + tcx: self.cx.tcx, + is_mutated: false, + local_id: unwrap_info.local_id, + }; + + let infcx = self.cx.tcx.infer_ctxt().build(); + let mut vis = ExprUseVisitor::new( + &mut delegate, + &infcx, + cond.hir_id.owner.def_id, + self.cx.param_env, + self.cx.typeck_results(), + ); + vis.walk_expr(cond); + vis.walk_expr(branch); + + if delegate.is_mutated { + // if the variable is mutated, we don't know whether it can be unwrapped. + // it might have been changed to `None` in between `is_some` + `unwrap`. continue; } self.unwrappables.push(unwrap_info); @@ -215,6 +283,27 @@ impl<'a, 'tcx> UnwrappableVariablesVisitor<'a, 'tcx> { } } +enum AsRefKind { + AsRef, + AsMut, +} + +/// Checks if the expression is a method call to `as_{ref,mut}` and returns the receiver of it. +/// If it isn't, the expression itself is returned. +fn consume_option_as_ref<'tcx>(expr: &'tcx Expr<'tcx>) -> (&'tcx Expr<'tcx>, Option<AsRefKind>) { + if let ExprKind::MethodCall(path, recv, ..) = expr.kind { + if path.ident.name == sym::as_ref { + (recv, Some(AsRefKind::AsRef)) + } else if path.ident.name.as_str() == "as_mut" { + (recv, Some(AsRefKind::AsMut)) + } else { + (expr, None) + } + } else { + (expr, None) + } +} + impl<'a, 'tcx> Visitor<'tcx> for UnwrappableVariablesVisitor<'a, 'tcx> { type NestedFilter = nested_filter::OnlyBodies; @@ -233,6 +322,7 @@ impl<'a, 'tcx> Visitor<'tcx> for UnwrappableVariablesVisitor<'a, 'tcx> { // find `unwrap[_err]()` calls: if_chain! { if let ExprKind::MethodCall(method_name, self_arg, ..) = expr.kind; + let (self_arg, as_ref_kind) = consume_option_as_ref(self_arg); if let Some(id) = path_to_local(self_arg); if [sym::unwrap, sym::expect, sym!(unwrap_err)].contains(&method_name.ident.name); let call_to_unwrap = [sym::unwrap, sym::expect].contains(&method_name.ident.name); @@ -268,7 +358,12 @@ impl<'a, 'tcx> Visitor<'tcx> for UnwrappableVariablesVisitor<'a, 'tcx> { unwrappable.check.span.with_lo(unwrappable.if_expr.span.lo()), "try", format!( - "if let {suggested_pattern} = {unwrappable_variable_name}", + "if let {suggested_pattern} = {borrow_prefix}{unwrappable_variable_name}", + borrow_prefix = match as_ref_kind { + Some(AsRefKind::AsRef) => "&", + Some(AsRefKind::AsMut) => "&mut ", + None => "", + }, ), // We don't track how the unwrapped value is used inside the // block or suggest deleting the unwrap, so we can't offer a diff --git a/clippy_lints/src/utils/conf.rs b/clippy_lints/src/utils/conf.rs index 58ae0656db7..26889475522 100644 --- a/clippy_lints/src/utils/conf.rs +++ b/clippy_lints/src/utils/conf.rs @@ -561,6 +561,26 @@ define_Conf! { /// Which crates to allow absolute paths from (absolute_paths_allowed_crates: rustc_data_structures::fx::FxHashSet<String> = rustc_data_structures::fx::FxHashSet::default()), + /// Lint: EXPLICIT_ITER_LOOP + /// + /// Whether to recommend using implicit into iter for reborrowed values. + /// + /// #### Example + /// ``` + /// let mut vec = vec![1, 2, 3]; + /// let rmvec = &mut vec; + /// for _ in rmvec.iter() {} + /// for _ in rmvec.iter_mut() {} + /// ``` + /// + /// Use instead: + /// ``` + /// let mut vec = vec![1, 2, 3]; + /// let rmvec = &mut vec; + /// for _ in &*rmvec {} + /// for _ in &mut *rmvec {} + /// ``` + (enforce_iter_loop_reborrow: bool = false), } /// Search for the configuration file. |
