809 lines
30 KiB
Rust
809 lines
30 KiB
Rust
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};
|
|
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::symbol::Symbol;
|
|
use rustc_span::{Span, sym};
|
|
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),
|
|
};
|
|
|
|
span_lint_and_sugg(
|
|
cx,
|
|
CMP_NULL,
|
|
expr.span,
|
|
"comparing with null is better expressed by the `.is_null()` method",
|
|
"try",
|
|
format!("{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 [(&'static str, &'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)
|
|
}
|
|
}
|
|
|
|
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) => (
|
|
[("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() => {
|
|
([("clone", ".to_owned()"), ("as_str", "")].as_slice(), DerefTy::Str)
|
|
},
|
|
Some(sym::PathBuf) => ([("clone", ".to_path_buf()"), ("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.as_str();
|
|
|
|
// 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)
|
|
}
|
|
}
|