| use clippy_utils::diagnostics::{span_lint_and_sugg, span_lint_and_then, span_lint_hir_and_then}; |
| use clippy_utils::source::SpanRangeExt; |
| use clippy_utils::sugg::Sugg; |
| use clippy_utils::visitors::contains_unsafe_block; |
| use clippy_utils::{get_expr_use_or_unification_node, is_lint_allowed, path_def_id, path_to_local, std_or_core, sym}; |
| use hir::LifetimeKind; |
| use rustc_abi::ExternAbi; |
| use rustc_errors::{Applicability, MultiSpan}; |
| use rustc_hir::hir_id::{HirId, HirIdMap}; |
| use rustc_hir::intravisit::{Visitor, walk_expr}; |
| use rustc_hir::{ |
| self as hir, AnonConst, BinOpKind, BindingMode, Body, Expr, ExprKind, FnRetTy, FnSig, GenericArg, ImplItemKind, |
| ItemKind, Lifetime, Mutability, Node, Param, PatKind, QPath, TraitFn, TraitItem, TraitItemKind, TyKind, |
| }; |
| use rustc_infer::infer::TyCtxtInferExt; |
| use rustc_infer::traits::{Obligation, ObligationCause}; |
| use rustc_lint::{LateContext, LateLintPass}; |
| use rustc_middle::hir::nested_filter; |
| use rustc_middle::ty::{self, Binder, ClauseKind, ExistentialPredicate, List, PredicateKind, Ty}; |
| use rustc_session::declare_lint_pass; |
| use rustc_span::Span; |
| use rustc_span::symbol::Symbol; |
| use rustc_trait_selection::infer::InferCtxtExt as _; |
| use rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt as _; |
| use std::{fmt, iter}; |
| |
| use crate::vec::is_allowed_vec_method; |
| |
| declare_clippy_lint! { |
| /// ### What it does |
| /// This lint checks for function arguments of type `&String`, `&Vec`, |
| /// `&PathBuf`, and `Cow<_>`. It will also suggest you replace `.clone()` calls |
| /// with the appropriate `.to_owned()`/`to_string()` calls. |
| /// |
| /// ### Why is this bad? |
| /// Requiring the argument to be of the specific type |
| /// makes the function less useful for no benefit; slices in the form of `&[T]` |
| /// or `&str` usually suffice and can be obtained from other types, too. |
| /// |
| /// ### Known problems |
| /// There may be `fn(&Vec)`-typed references pointing to your function. |
| /// If you have them, you will get a compiler error after applying this lint's |
| /// suggestions. You then have the choice to undo your changes or change the |
| /// type of the reference. |
| /// |
| /// Note that if the function is part of your public interface, there may be |
| /// other crates referencing it, of which you may not be aware. Carefully |
| /// deprecate the function before applying the lint suggestions in this case. |
| /// |
| /// ### Example |
| /// ```ignore |
| /// fn foo(&Vec<u32>) { .. } |
| /// ``` |
| /// |
| /// Use instead: |
| /// ```ignore |
| /// fn foo(&[u32]) { .. } |
| /// ``` |
| #[clippy::version = "pre 1.29.0"] |
| pub PTR_ARG, |
| style, |
| "fn arguments of the type `&Vec<...>` or `&String`, suggesting to use `&[...]` or `&str` instead, respectively" |
| } |
| |
| declare_clippy_lint! { |
| /// ### What it does |
| /// This lint checks for equality comparisons with `ptr::null` |
| /// |
| /// ### Why is this bad? |
| /// It's easier and more readable to use the inherent |
| /// `.is_null()` |
| /// method instead |
| /// |
| /// ### Example |
| /// ```rust,ignore |
| /// use std::ptr; |
| /// |
| /// if x == ptr::null { |
| /// // .. |
| /// } |
| /// ``` |
| /// |
| /// Use instead: |
| /// ```rust,ignore |
| /// if x.is_null() { |
| /// // .. |
| /// } |
| /// ``` |
| #[clippy::version = "pre 1.29.0"] |
| pub CMP_NULL, |
| style, |
| "comparing a pointer to a null pointer, suggesting to use `.is_null()` instead" |
| } |
| |
| declare_clippy_lint! { |
| /// ### What it does |
| /// This lint checks for functions that take immutable references and return |
| /// mutable ones. This will not trigger if no unsafe code exists as there |
| /// are multiple safe functions which will do this transformation |
| /// |
| /// To be on the conservative side, if there's at least one mutable |
| /// reference with the output lifetime, this lint will not trigger. |
| /// |
| /// ### Why is this bad? |
| /// Creating a mutable reference which can be repeatably derived from an |
| /// immutable reference is unsound as it allows creating multiple live |
| /// mutable references to the same object. |
| /// |
| /// This [error](https://github.com/rust-lang/rust/issues/39465) actually |
| /// lead to an interim Rust release 1.15.1. |
| /// |
| /// ### Known problems |
| /// This pattern is used by memory allocators to allow allocating multiple |
| /// objects while returning mutable references to each one. So long as |
| /// different mutable references are returned each time such a function may |
| /// be safe. |
| /// |
| /// ### Example |
| /// ```ignore |
| /// fn foo(&Foo) -> &mut Bar { .. } |
| /// ``` |
| #[clippy::version = "pre 1.29.0"] |
| pub MUT_FROM_REF, |
| correctness, |
| "fns that create mutable refs from immutable ref args" |
| } |
| |
| declare_clippy_lint! { |
| /// ### What it does |
| /// Use `std::ptr::eq` when applicable |
| /// |
| /// ### Why is this bad? |
| /// `ptr::eq` can be used to compare `&T` references |
| /// (which coerce to `*const T` implicitly) by their address rather than |
| /// comparing the values they point to. |
| /// |
| /// ### Example |
| /// ```no_run |
| /// let a = &[1, 2, 3]; |
| /// let b = &[1, 2, 3]; |
| /// |
| /// assert!(a as *const _ as usize == b as *const _ as usize); |
| /// ``` |
| /// Use instead: |
| /// ```no_run |
| /// let a = &[1, 2, 3]; |
| /// let b = &[1, 2, 3]; |
| /// |
| /// assert!(std::ptr::eq(a, b)); |
| /// ``` |
| #[clippy::version = "1.49.0"] |
| pub PTR_EQ, |
| style, |
| "use `std::ptr::eq` when comparing raw pointers" |
| } |
| |
| declare_lint_pass!(Ptr => [PTR_ARG, CMP_NULL, MUT_FROM_REF, PTR_EQ]); |
| |
| impl<'tcx> LateLintPass<'tcx> for Ptr { |
| fn check_trait_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx TraitItem<'_>) { |
| if let TraitItemKind::Fn(sig, trait_method) = &item.kind { |
| if matches!(trait_method, TraitFn::Provided(_)) { |
| // Handled by check body. |
| return; |
| } |
| |
| check_mut_from_ref(cx, sig, None); |
| |
| if !matches!(sig.header.abi, ExternAbi::Rust) { |
| // Ignore `extern` functions with non-Rust calling conventions |
| return; |
| } |
| |
| for arg in check_fn_args( |
| cx, |
| cx.tcx.fn_sig(item.owner_id).instantiate_identity().skip_binder(), |
| sig.decl.inputs, |
| &[], |
| ) |
| .filter(|arg| arg.mutability() == Mutability::Not) |
| { |
| span_lint_hir_and_then(cx, PTR_ARG, arg.emission_id, arg.span, arg.build_msg(), |diag| { |
| diag.span_suggestion( |
| arg.span, |
| "change this to", |
| format!("{}{}", arg.ref_prefix, arg.deref_ty.display(cx)), |
| Applicability::Unspecified, |
| ); |
| }); |
| } |
| } |
| } |
| |
| fn check_body(&mut self, cx: &LateContext<'tcx>, body: &Body<'tcx>) { |
| let mut parents = cx.tcx.hir_parent_iter(body.value.hir_id); |
| let (item_id, sig, is_trait_item) = match parents.next() { |
| Some((_, Node::Item(i))) => { |
| if let ItemKind::Fn { sig, .. } = &i.kind { |
| (i.owner_id, sig, false) |
| } else { |
| return; |
| } |
| }, |
| Some((_, Node::ImplItem(i))) => { |
| if !matches!(parents.next(), |
| Some((_, Node::Item(i))) if matches!(&i.kind, ItemKind::Impl(i) if i.of_trait.is_none()) |
| ) { |
| return; |
| } |
| if let ImplItemKind::Fn(sig, _) = &i.kind { |
| (i.owner_id, sig, false) |
| } else { |
| return; |
| } |
| }, |
| Some((_, Node::TraitItem(i))) => { |
| if let TraitItemKind::Fn(sig, _) = &i.kind { |
| (i.owner_id, sig, true) |
| } else { |
| return; |
| } |
| }, |
| _ => return, |
| }; |
| |
| check_mut_from_ref(cx, sig, Some(body)); |
| |
| if !matches!(sig.header.abi, ExternAbi::Rust) { |
| // Ignore `extern` functions with non-Rust calling conventions |
| return; |
| } |
| |
| let decl = sig.decl; |
| let sig = cx.tcx.fn_sig(item_id).instantiate_identity().skip_binder(); |
| let lint_args: Vec<_> = check_fn_args(cx, sig, decl.inputs, body.params) |
| .filter(|arg| !is_trait_item || arg.mutability() == Mutability::Not) |
| .collect(); |
| let results = check_ptr_arg_usage(cx, body, &lint_args); |
| |
| for (result, args) in results.iter().zip(lint_args.iter()).filter(|(r, _)| !r.skip) { |
| span_lint_hir_and_then(cx, PTR_ARG, args.emission_id, args.span, args.build_msg(), |diag| { |
| diag.multipart_suggestion( |
| "change this to", |
| iter::once((args.span, format!("{}{}", args.ref_prefix, args.deref_ty.display(cx)))) |
| .chain(result.replacements.iter().map(|r| { |
| ( |
| r.expr_span, |
| format!("{}{}", r.self_span.get_source_text(cx).unwrap(), r.replacement), |
| ) |
| })) |
| .collect(), |
| Applicability::Unspecified, |
| ); |
| }); |
| } |
| } |
| |
| fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) { |
| if let ExprKind::Binary(op, l, r) = expr.kind |
| && (op.node == BinOpKind::Eq || op.node == BinOpKind::Ne) |
| { |
| let non_null_path_snippet = match ( |
| is_lint_allowed(cx, CMP_NULL, expr.hir_id), |
| is_null_path(cx, l), |
| is_null_path(cx, r), |
| ) { |
| (false, true, false) if let Some(sugg) = Sugg::hir_opt(cx, r) => sugg.maybe_paren(), |
| (false, false, true) if let Some(sugg) = Sugg::hir_opt(cx, l) => sugg.maybe_paren(), |
| _ => return check_ptr_eq(cx, expr, op.node, l, r), |
| }; |
| let invert = if op.node == BinOpKind::Eq { "" } else { "!" }; |
| |
| span_lint_and_sugg( |
| cx, |
| CMP_NULL, |
| expr.span, |
| "comparing with null is better expressed by the `.is_null()` method", |
| "try", |
| format!("{invert}{non_null_path_snippet}.is_null()",), |
| Applicability::MachineApplicable, |
| ); |
| } |
| } |
| } |
| |
| #[derive(Default)] |
| struct PtrArgResult { |
| skip: bool, |
| replacements: Vec<PtrArgReplacement>, |
| } |
| |
| struct PtrArgReplacement { |
| expr_span: Span, |
| self_span: Span, |
| replacement: &'static str, |
| } |
| |
| struct PtrArg<'tcx> { |
| idx: usize, |
| emission_id: HirId, |
| span: Span, |
| ty_name: Symbol, |
| method_renames: &'static [(Symbol, &'static str)], |
| ref_prefix: RefPrefix, |
| deref_ty: DerefTy<'tcx>, |
| } |
| impl PtrArg<'_> { |
| fn build_msg(&self) -> String { |
| format!( |
| "writing `&{}{}` instead of `&{}{}` involves a new object where a slice will do", |
| self.ref_prefix.mutability.prefix_str(), |
| self.ty_name, |
| self.ref_prefix.mutability.prefix_str(), |
| self.deref_ty.argless_str(), |
| ) |
| } |
| |
| fn mutability(&self) -> Mutability { |
| self.ref_prefix.mutability |
| } |
| } |
| |
| struct RefPrefix { |
| lt: Lifetime, |
| mutability: Mutability, |
| } |
| impl fmt::Display for RefPrefix { |
| fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| use fmt::Write; |
| f.write_char('&')?; |
| if !self.lt.is_anonymous() { |
| self.lt.ident.fmt(f)?; |
| f.write_char(' ')?; |
| } |
| f.write_str(self.mutability.prefix_str()) |
| } |
| } |
| |
| struct DerefTyDisplay<'a, 'tcx>(&'a LateContext<'tcx>, &'a DerefTy<'tcx>); |
| impl fmt::Display for DerefTyDisplay<'_, '_> { |
| fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| use std::fmt::Write; |
| match self.1 { |
| DerefTy::Str => f.write_str("str"), |
| DerefTy::Path => f.write_str("Path"), |
| DerefTy::Slice(hir_ty, ty) => { |
| f.write_char('[')?; |
| match hir_ty.and_then(|s| s.get_source_text(self.0)) { |
| Some(s) => f.write_str(&s)?, |
| None => ty.fmt(f)?, |
| } |
| f.write_char(']') |
| }, |
| } |
| } |
| } |
| |
| enum DerefTy<'tcx> { |
| Str, |
| Path, |
| Slice(Option<Span>, Ty<'tcx>), |
| } |
| impl<'tcx> DerefTy<'tcx> { |
| fn ty(&self, cx: &LateContext<'tcx>) -> Ty<'tcx> { |
| match *self { |
| Self::Str => cx.tcx.types.str_, |
| Self::Path => Ty::new_adt( |
| cx.tcx, |
| cx.tcx.adt_def(cx.tcx.get_diagnostic_item(sym::Path).unwrap()), |
| List::empty(), |
| ), |
| Self::Slice(_, ty) => Ty::new_slice(cx.tcx, ty), |
| } |
| } |
| |
| fn argless_str(&self) -> &'static str { |
| match *self { |
| Self::Str => "str", |
| Self::Path => "Path", |
| Self::Slice(..) => "[_]", |
| } |
| } |
| |
| fn display<'a>(&'a self, cx: &'a LateContext<'tcx>) -> DerefTyDisplay<'a, 'tcx> { |
| DerefTyDisplay(cx, self) |
| } |
| } |
| |
| #[expect(clippy::too_many_lines)] |
| fn check_fn_args<'cx, 'tcx: 'cx>( |
| cx: &'cx LateContext<'tcx>, |
| fn_sig: ty::FnSig<'tcx>, |
| hir_tys: &'tcx [hir::Ty<'tcx>], |
| params: &'tcx [Param<'tcx>], |
| ) -> impl Iterator<Item = PtrArg<'tcx>> + 'cx { |
| fn_sig |
| .inputs() |
| .iter() |
| .zip(hir_tys.iter()) |
| .enumerate() |
| .filter_map(move |(i, (ty, hir_ty))| { |
| if let ty::Ref(_, ty, mutability) = *ty.kind() |
| && let ty::Adt(adt, args) = *ty.kind() |
| && let TyKind::Ref(lt, ref ty) = hir_ty.kind |
| && let TyKind::Path(QPath::Resolved(None, path)) = ty.ty.kind |
| // Check that the name as typed matches the actual name of the type. |
| // e.g. `fn foo(_: &Foo)` shouldn't trigger the lint when `Foo` is an alias for `Vec` |
| && let [.., name] = path.segments |
| && cx.tcx.item_name(adt.did()) == name.ident.name |
| { |
| let emission_id = params.get(i).map_or(hir_ty.hir_id, |param| param.hir_id); |
| let (method_renames, deref_ty) = match cx.tcx.get_diagnostic_name(adt.did()) { |
| Some(sym::Vec) => ( |
| [(sym::clone, ".to_owned()")].as_slice(), |
| DerefTy::Slice( |
| name.args.and_then(|args| args.args.first()).and_then(|arg| { |
| if let GenericArg::Type(ty) = arg { |
| Some(ty.span) |
| } else { |
| None |
| } |
| }), |
| args.type_at(0), |
| ), |
| ), |
| _ if Some(adt.did()) == cx.tcx.lang_items().string() => ( |
| [(sym::clone, ".to_owned()"), (sym::as_str, "")].as_slice(), |
| DerefTy::Str, |
| ), |
| Some(sym::PathBuf) => ( |
| [(sym::clone, ".to_path_buf()"), (sym::as_path, "")].as_slice(), |
| DerefTy::Path, |
| ), |
| Some(sym::Cow) if mutability == Mutability::Not => { |
| if let Some((lifetime, ty)) = name.args.and_then(|args| { |
| if let [GenericArg::Lifetime(lifetime), ty] = args.args { |
| return Some((lifetime, ty)); |
| } |
| None |
| }) { |
| if let LifetimeKind::Param(param_def_id) = lifetime.kind |
| && !lifetime.is_anonymous() |
| && fn_sig |
| .output() |
| .walk() |
| .filter_map(|arg| { |
| arg.as_region().and_then(|lifetime| match lifetime.kind() { |
| ty::ReEarlyParam(r) => Some( |
| cx.tcx |
| .generics_of(cx.tcx.parent(param_def_id.to_def_id())) |
| .region_param(r, cx.tcx) |
| .def_id, |
| ), |
| ty::ReBound(_, r) => r.kind.get_id(), |
| ty::ReLateParam(r) => r.kind.get_id(), |
| ty::ReStatic |
| | ty::ReVar(_) |
| | ty::RePlaceholder(_) |
| | ty::ReErased |
| | ty::ReError(_) => None, |
| }) |
| }) |
| .any(|def_id| def_id.as_local().is_some_and(|def_id| def_id == param_def_id)) |
| { |
| // `&Cow<'a, T>` when the return type uses 'a is okay |
| return None; |
| } |
| |
| span_lint_hir_and_then( |
| cx, |
| PTR_ARG, |
| emission_id, |
| hir_ty.span, |
| "using a reference to `Cow` is not recommended", |
| |diag| { |
| diag.span_suggestion( |
| hir_ty.span, |
| "change this to", |
| match ty.span().get_source_text(cx) { |
| Some(s) => format!("&{}{s}", mutability.prefix_str()), |
| None => format!("&{}{}", mutability.prefix_str(), args.type_at(1)), |
| }, |
| Applicability::Unspecified, |
| ); |
| }, |
| ); |
| } |
| return None; |
| }, |
| _ => return None, |
| }; |
| return Some(PtrArg { |
| idx: i, |
| emission_id, |
| span: hir_ty.span, |
| ty_name: name.ident.name, |
| method_renames, |
| ref_prefix: RefPrefix { lt: *lt, mutability }, |
| deref_ty, |
| }); |
| } |
| None |
| }) |
| } |
| |
| fn check_mut_from_ref<'tcx>(cx: &LateContext<'tcx>, sig: &FnSig<'_>, body: Option<&Body<'tcx>>) { |
| let FnRetTy::Return(ty) = sig.decl.output else { return }; |
| for (out, mutability, out_span) in get_lifetimes(ty) { |
| if mutability != Some(Mutability::Mut) { |
| continue; |
| } |
| let out_region = cx.tcx.named_bound_var(out.hir_id); |
| // `None` if one of the types contains `&'a mut T` or `T<'a>`. |
| // Else, contains all the locations of `&'a T` types. |
| let args_immut_refs: Option<Vec<Span>> = sig |
| .decl |
| .inputs |
| .iter() |
| .flat_map(get_lifetimes) |
| .filter(|&(lt, _, _)| cx.tcx.named_bound_var(lt.hir_id) == out_region) |
| .map(|(_, mutability, span)| (mutability == Some(Mutability::Not)).then_some(span)) |
| .collect(); |
| if let Some(args_immut_refs) = args_immut_refs |
| && !args_immut_refs.is_empty() |
| && body.is_none_or(|body| sig.header.is_unsafe() || contains_unsafe_block(cx, body.value)) |
| { |
| span_lint_and_then( |
| cx, |
| MUT_FROM_REF, |
| out_span, |
| "mutable borrow from immutable input(s)", |
| |diag| { |
| let ms = MultiSpan::from_spans(args_immut_refs); |
| diag.span_note(ms, "immutable borrow here"); |
| }, |
| ); |
| } |
| } |
| } |
| |
| #[expect(clippy::too_many_lines)] |
| fn check_ptr_arg_usage<'tcx>(cx: &LateContext<'tcx>, body: &Body<'tcx>, args: &[PtrArg<'tcx>]) -> Vec<PtrArgResult> { |
| struct V<'cx, 'tcx> { |
| cx: &'cx LateContext<'tcx>, |
| /// Map from a local id to which argument it came from (index into `Self::args` and |
| /// `Self::results`) |
| bindings: HirIdMap<usize>, |
| /// The arguments being checked. |
| args: &'cx [PtrArg<'tcx>], |
| /// The results for each argument (len should match args.len) |
| results: Vec<PtrArgResult>, |
| /// The number of arguments which can't be linted. Used to return early. |
| skip_count: usize, |
| } |
| impl<'tcx> Visitor<'tcx> for V<'_, 'tcx> { |
| type NestedFilter = nested_filter::OnlyBodies; |
| fn maybe_tcx(&mut self) -> Self::MaybeTyCtxt { |
| self.cx.tcx |
| } |
| |
| fn visit_anon_const(&mut self, _: &'tcx AnonConst) {} |
| |
| fn visit_expr(&mut self, e: &'tcx Expr<'_>) { |
| if self.skip_count == self.args.len() { |
| return; |
| } |
| |
| // Check if this is local we care about |
| let Some(&args_idx) = path_to_local(e).and_then(|id| self.bindings.get(&id)) else { |
| return walk_expr(self, e); |
| }; |
| let args = &self.args[args_idx]; |
| let result = &mut self.results[args_idx]; |
| |
| // Helper function to handle early returns. |
| let mut set_skip_flag = || { |
| if !result.skip { |
| self.skip_count += 1; |
| } |
| result.skip = true; |
| }; |
| |
| match get_expr_use_or_unification_node(self.cx.tcx, e) { |
| Some((Node::Stmt(_), _)) => (), |
| Some((Node::LetStmt(l), _)) => { |
| // Only trace simple bindings. e.g `let x = y;` |
| if let PatKind::Binding(BindingMode::NONE, id, _, None) = l.pat.kind { |
| self.bindings.insert(id, args_idx); |
| } else { |
| set_skip_flag(); |
| } |
| }, |
| Some((Node::Expr(use_expr), child_id)) => { |
| if let ExprKind::Index(e, ..) = use_expr.kind |
| && e.hir_id == child_id |
| { |
| // Indexing works with both owned and its dereferenced type |
| return; |
| } |
| |
| if let ExprKind::MethodCall(name, receiver, ..) = use_expr.kind |
| && receiver.hir_id == child_id |
| { |
| let name = name.ident.name; |
| |
| // Check if the method can be renamed. |
| if let Some((_, replacement)) = args.method_renames.iter().find(|&&(x, _)| x == name) { |
| result.replacements.push(PtrArgReplacement { |
| expr_span: use_expr.span, |
| self_span: receiver.span, |
| replacement, |
| }); |
| return; |
| } |
| |
| // Some methods exist on both `[T]` and `Vec<T>`, such as `len`, where the receiver type |
| // doesn't coerce to a slice and our adjusted type check below isn't enough, |
| // but it would still be valid to call with a slice |
| if is_allowed_vec_method(self.cx, use_expr) { |
| return; |
| } |
| } |
| |
| let deref_ty = args.deref_ty.ty(self.cx); |
| let adjusted_ty = self.cx.typeck_results().expr_ty_adjusted(e).peel_refs(); |
| if adjusted_ty == deref_ty { |
| return; |
| } |
| |
| if let ty::Dynamic(preds, ..) = adjusted_ty.kind() |
| && matches_preds(self.cx, deref_ty, preds) |
| { |
| return; |
| } |
| |
| set_skip_flag(); |
| }, |
| _ => set_skip_flag(), |
| } |
| } |
| } |
| |
| let mut skip_count = 0; |
| let mut results = args.iter().map(|_| PtrArgResult::default()).collect::<Vec<_>>(); |
| let mut v = V { |
| cx, |
| bindings: args |
| .iter() |
| .enumerate() |
| .filter_map(|(i, arg)| { |
| let param = &body.params[arg.idx]; |
| match param.pat.kind { |
| PatKind::Binding(BindingMode::NONE, id, _, None) if !is_lint_allowed(cx, PTR_ARG, param.hir_id) => { |
| Some((id, i)) |
| }, |
| _ => { |
| skip_count += 1; |
| results[i].skip = true; |
| None |
| }, |
| } |
| }) |
| .collect(), |
| args, |
| results, |
| skip_count, |
| }; |
| v.visit_expr(body.value); |
| v.results |
| } |
| |
| fn matches_preds<'tcx>( |
| cx: &LateContext<'tcx>, |
| ty: Ty<'tcx>, |
| preds: &'tcx [ty::PolyExistentialPredicate<'tcx>], |
| ) -> bool { |
| let infcx = cx.tcx.infer_ctxt().build(cx.typing_mode()); |
| preds |
| .iter() |
| .all(|&p| match cx.tcx.instantiate_bound_regions_with_erased(p) { |
| ExistentialPredicate::Trait(p) => infcx |
| .type_implements_trait(p.def_id, [ty.into()].into_iter().chain(p.args.iter()), cx.param_env) |
| .must_apply_modulo_regions(), |
| ExistentialPredicate::Projection(p) => infcx.predicate_must_hold_modulo_regions(&Obligation::new( |
| cx.tcx, |
| ObligationCause::dummy(), |
| cx.param_env, |
| cx.tcx |
| .mk_predicate(Binder::dummy(PredicateKind::Clause(ClauseKind::Projection( |
| p.with_self_ty(cx.tcx, ty), |
| )))), |
| )), |
| ExistentialPredicate::AutoTrait(p) => infcx |
| .type_implements_trait(p, [ty], cx.param_env) |
| .must_apply_modulo_regions(), |
| }) |
| } |
| |
| struct LifetimeVisitor<'tcx> { |
| result: Vec<(&'tcx Lifetime, Option<Mutability>, Span)>, |
| } |
| |
| impl<'tcx> Visitor<'tcx> for LifetimeVisitor<'tcx> { |
| fn visit_ty(&mut self, ty: &'tcx hir::Ty<'tcx, hir::AmbigArg>) { |
| if let TyKind::Ref(lt, ref m) = ty.kind { |
| self.result.push((lt, Some(m.mutbl), ty.span)); |
| } |
| hir::intravisit::walk_ty(self, ty); |
| } |
| |
| fn visit_generic_arg(&mut self, generic_arg: &'tcx GenericArg<'tcx>) { |
| if let GenericArg::Lifetime(lt) = generic_arg { |
| self.result.push((lt, None, generic_arg.span())); |
| } |
| hir::intravisit::walk_generic_arg(self, generic_arg); |
| } |
| } |
| |
| /// Visit `ty` and collect the all the lifetimes appearing in it, implicit or not. |
| /// |
| /// The second field of the vector's elements indicate if the lifetime is attached to a |
| /// shared reference, a mutable reference, or neither. |
| fn get_lifetimes<'tcx>(ty: &'tcx hir::Ty<'tcx>) -> Vec<(&'tcx Lifetime, Option<Mutability>, Span)> { |
| use hir::intravisit::VisitorExt as _; |
| |
| let mut visitor = LifetimeVisitor { result: Vec::new() }; |
| visitor.visit_ty_unambig(ty); |
| visitor.result |
| } |
| |
| fn is_null_path(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool { |
| if let ExprKind::Call(pathexp, []) = expr.kind { |
| path_def_id(cx, pathexp) |
| .is_some_and(|id| matches!(cx.tcx.get_diagnostic_name(id), Some(sym::ptr_null | sym::ptr_null_mut))) |
| } else { |
| false |
| } |
| } |
| |
| fn check_ptr_eq<'tcx>( |
| cx: &LateContext<'tcx>, |
| expr: &'tcx Expr<'_>, |
| op: BinOpKind, |
| left: &'tcx Expr<'_>, |
| right: &'tcx Expr<'_>, |
| ) { |
| if expr.span.from_expansion() { |
| return; |
| } |
| |
| // Remove one level of usize conversion if any |
| let (left, right, usize_peeled) = match (expr_as_cast_to_usize(cx, left), expr_as_cast_to_usize(cx, right)) { |
| (Some(lhs), Some(rhs)) => (lhs, rhs, true), |
| _ => (left, right, false), |
| }; |
| |
| // This lint concerns raw pointers |
| let (left_ty, right_ty) = (cx.typeck_results().expr_ty(left), cx.typeck_results().expr_ty(right)); |
| if !left_ty.is_raw_ptr() || !right_ty.is_raw_ptr() { |
| return; |
| } |
| |
| let ((left_var, left_casts_peeled), (right_var, right_casts_peeled)) = |
| (peel_raw_casts(cx, left, left_ty), peel_raw_casts(cx, right, right_ty)); |
| |
| if !(usize_peeled || left_casts_peeled || right_casts_peeled) { |
| return; |
| } |
| |
| let mut app = Applicability::MachineApplicable; |
| let left_snip = Sugg::hir_with_context(cx, left_var, expr.span.ctxt(), "_", &mut app); |
| let right_snip = Sugg::hir_with_context(cx, right_var, expr.span.ctxt(), "_", &mut app); |
| { |
| let Some(top_crate) = std_or_core(cx) else { return }; |
| let invert = if op == BinOpKind::Eq { "" } else { "!" }; |
| span_lint_and_sugg( |
| cx, |
| PTR_EQ, |
| expr.span, |
| format!("use `{top_crate}::ptr::eq` when comparing raw pointers"), |
| "try", |
| format!("{invert}{top_crate}::ptr::eq({left_snip}, {right_snip})"), |
| app, |
| ); |
| } |
| } |
| |
| // If the given expression is a cast to a usize, return the lhs of the cast |
| // E.g., `foo as *const _ as usize` returns `foo as *const _`. |
| fn expr_as_cast_to_usize<'tcx>(cx: &LateContext<'tcx>, cast_expr: &'tcx Expr<'_>) -> Option<&'tcx Expr<'tcx>> { |
| if !cast_expr.span.from_expansion() |
| && cx.typeck_results().expr_ty(cast_expr) == cx.tcx.types.usize |
| && let ExprKind::Cast(expr, _) = cast_expr.kind |
| { |
| Some(expr) |
| } else { |
| None |
| } |
| } |
| |
| // Peel raw casts if the remaining expression can be coerced to it, and whether casts have been |
| // peeled or not. |
| fn peel_raw_casts<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>, expr_ty: Ty<'tcx>) -> (&'tcx Expr<'tcx>, bool) { |
| if !expr.span.from_expansion() |
| && let ExprKind::Cast(inner, _) = expr.kind |
| && let ty::RawPtr(target_ty, _) = expr_ty.kind() |
| && let inner_ty = cx.typeck_results().expr_ty(inner) |
| && let ty::RawPtr(inner_target_ty, _) | ty::Ref(_, inner_target_ty, _) = inner_ty.kind() |
| && target_ty == inner_target_ty |
| { |
| (peel_raw_casts(cx, inner, inner_ty).0, true) |
| } else { |
| (expr, false) |
| } |
| } |
