diff options
Diffstat (limited to 'src/tools/clippy/clippy_lints/src/casts')
9 files changed, 246 insertions, 15 deletions
diff --git a/src/tools/clippy/clippy_lints/src/casts/as_underscore.rs b/src/tools/clippy/clippy_lints/src/casts/as_underscore.rs new file mode 100644 index 000000000..56e894c62 --- /dev/null +++ b/src/tools/clippy/clippy_lints/src/casts/as_underscore.rs @@ -0,0 +1,25 @@ +use clippy_utils::diagnostics::span_lint_and_then; +use rustc_errors::Applicability; +use rustc_hir::{Expr, Ty, TyKind}; +use rustc_lint::LateContext; +use rustc_middle::ty; + +use super::AS_UNDERSCORE; + +pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, ty: &'tcx Ty<'_>) { + if matches!(ty.kind, TyKind::Infer) { + span_lint_and_then(cx, AS_UNDERSCORE, expr.span, "using `as _` conversion", |diag| { + let ty_resolved = cx.typeck_results().expr_ty(expr); + if let ty::Error(_) = ty_resolved.kind() { + diag.help("consider giving the type explicitly"); + } else { + diag.span_suggestion( + ty.span, + "consider giving the type explicitly", + ty_resolved, + Applicability::MachineApplicable, + ); + } + }); + } +} diff --git a/src/tools/clippy/clippy_lints/src/casts/borrow_as_ptr.rs b/src/tools/clippy/clippy_lints/src/casts/borrow_as_ptr.rs new file mode 100644 index 000000000..6e1f8cd64 --- /dev/null +++ b/src/tools/clippy/clippy_lints/src/casts/borrow_as_ptr.rs @@ -0,0 +1,37 @@ +use clippy_utils::diagnostics::span_lint_and_sugg; +use clippy_utils::is_no_std_crate; +use clippy_utils::source::snippet_with_context; +use rustc_errors::Applicability; +use rustc_hir::{BorrowKind, Expr, ExprKind, Mutability, Ty, TyKind}; +use rustc_lint::LateContext; + +use super::BORROW_AS_PTR; + +pub(super) fn check<'tcx>( + cx: &LateContext<'tcx>, + expr: &'tcx Expr<'_>, + cast_expr: &'tcx Expr<'_>, + cast_to: &'tcx Ty<'_>, +) { + if matches!(cast_to.kind, TyKind::Ptr(_)) + && let ExprKind::AddrOf(BorrowKind::Ref, mutability, e) = cast_expr.kind + { + let core_or_std = if is_no_std_crate(cx) { "core" } else { "std" }; + let macro_name = match mutability { + Mutability::Not => "addr_of", + Mutability::Mut => "addr_of_mut", + }; + let mut app = Applicability::MachineApplicable; + let snip = snippet_with_context(cx, e.span, cast_expr.span.ctxt(), "..", &mut app).0; + + span_lint_and_sugg( + cx, + BORROW_AS_PTR, + expr.span, + "borrow as raw pointer", + "try", + format!("{}::ptr::{}!({})", core_or_std, macro_name, snip), + Applicability::MachineApplicable, + ); + } +} diff --git a/src/tools/clippy/clippy_lints/src/casts/cast_abs_to_unsigned.rs b/src/tools/clippy/clippy_lints/src/casts/cast_abs_to_unsigned.rs index 64ea326b7..3f1edabe6 100644 --- a/src/tools/clippy/clippy_lints/src/casts/cast_abs_to_unsigned.rs +++ b/src/tools/clippy/clippy_lints/src/casts/cast_abs_to_unsigned.rs @@ -20,7 +20,7 @@ pub(super) fn check( if meets_msrv(msrv, msrvs::UNSIGNED_ABS) && let ty::Int(from) = cast_from.kind() && let ty::Uint(to) = cast_to.kind() - && let ExprKind::MethodCall(method_path, args, _) = cast_expr.kind + && let ExprKind::MethodCall(method_path, receiver, ..) = cast_expr.kind && method_path.ident.name.as_str() == "abs" { let span = if from.bit_width() == to.bit_width() { @@ -37,7 +37,7 @@ pub(super) fn check( span, &format!("casting the result of `{cast_from}::abs()` to {cast_to}"), "replace with", - format!("{}.unsigned_abs()", Sugg::hir(cx, &args[0], "..")), + format!("{}.unsigned_abs()", Sugg::hir(cx, receiver, "..").maybe_par()), Applicability::MachineApplicable, ); } diff --git a/src/tools/clippy/clippy_lints/src/casts/cast_possible_truncation.rs b/src/tools/clippy/clippy_lints/src/casts/cast_possible_truncation.rs index 64f87c80f..406547a44 100644 --- a/src/tools/clippy/clippy_lints/src/casts/cast_possible_truncation.rs +++ b/src/tools/clippy/clippy_lints/src/casts/cast_possible_truncation.rs @@ -44,7 +44,7 @@ fn apply_reductions(cx: &LateContext<'_>, nbits: u64, expr: &Expr<'_>, signed: b .saturating_sub(constant_int(cx, right).map_or(0, |s| u64::try_from(s).expect("shift too high"))), _ => nbits, }, - ExprKind::MethodCall(method, [left, right], _) => { + ExprKind::MethodCall(method, left, [right], _) => { if signed { return nbits; } @@ -55,7 +55,7 @@ fn apply_reductions(cx: &LateContext<'_>, nbits: u64, expr: &Expr<'_>, signed: b }; apply_reductions(cx, nbits, left, signed).min(max_bits.unwrap_or(u64::max_value())) }, - ExprKind::MethodCall(method, [_, lo, hi], _) => { + ExprKind::MethodCall(method, _, [lo, hi], _) => { if method.ident.as_str() == "clamp" { //FIXME: make this a diagnostic item if let (Some(lo_bits), Some(hi_bits)) = (get_constant_bits(cx, lo), get_constant_bits(cx, hi)) { @@ -64,7 +64,7 @@ fn apply_reductions(cx: &LateContext<'_>, nbits: u64, expr: &Expr<'_>, signed: b } nbits }, - ExprKind::MethodCall(method, [_value], _) => { + ExprKind::MethodCall(method, _value, [], _) => { if method.ident.name.as_str() == "signum" { 0 // do not lint if cast comes from a `signum` function } else { diff --git a/src/tools/clippy/clippy_lints/src/casts/cast_ptr_alignment.rs b/src/tools/clippy/clippy_lints/src/casts/cast_ptr_alignment.rs index d476a1a76..da7b12f67 100644 --- a/src/tools/clippy/clippy_lints/src/casts/cast_ptr_alignment.rs +++ b/src/tools/clippy/clippy_lints/src/casts/cast_ptr_alignment.rs @@ -18,7 +18,7 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>) { cx.typeck_results().expr_ty(expr), ); lint_cast_ptr_alignment(cx, expr, cast_from, cast_to); - } else if let ExprKind::MethodCall(method_path, [self_arg, ..], _) = &expr.kind { + } else if let ExprKind::MethodCall(method_path, self_arg, ..) = &expr.kind { if method_path.ident.name == sym!(cast) && let Some(generic_args) = method_path.args && let [GenericArg::Type(cast_to)] = generic_args.args @@ -64,7 +64,7 @@ fn is_used_as_unaligned(cx: &LateContext<'_>, e: &Expr<'_>) -> bool { return false; }; match parent.kind { - ExprKind::MethodCall(name, [self_arg, ..], _) if self_arg.hir_id == e.hir_id => { + ExprKind::MethodCall(name, self_arg, ..) if self_arg.hir_id == e.hir_id => { if matches!(name.ident.as_str(), "read_unaligned" | "write_unaligned") && let Some(def_id) = cx.typeck_results().type_dependent_def_id(parent.hir_id) && let Some(def_id) = cx.tcx.impl_of_method(def_id) diff --git a/src/tools/clippy/clippy_lints/src/casts/cast_sign_loss.rs b/src/tools/clippy/clippy_lints/src/casts/cast_sign_loss.rs index 75f70b77e..5b59350be 100644 --- a/src/tools/clippy/clippy_lints/src/casts/cast_sign_loss.rs +++ b/src/tools/clippy/clippy_lints/src/casts/cast_sign_loss.rs @@ -41,14 +41,14 @@ fn should_lint(cx: &LateContext<'_>, cast_op: &Expr<'_>, cast_from: Ty<'_>, cast } // Don't lint for the result of methods that always return non-negative values. - if let ExprKind::MethodCall(path, _, _) = cast_op.kind { + if let ExprKind::MethodCall(path, ..) = cast_op.kind { let mut method_name = path.ident.name.as_str(); let allowed_methods = ["abs", "checked_abs", "rem_euclid", "checked_rem_euclid"]; if_chain! { if method_name == "unwrap"; if let Some(arglist) = method_chain_args(cast_op, &["unwrap"]); - if let ExprKind::MethodCall(inner_path, _, _) = &arglist[0][0].kind; + if let ExprKind::MethodCall(inner_path, ..) = &arglist[0].0.kind; then { method_name = inner_path.ident.name.as_str(); } diff --git a/src/tools/clippy/clippy_lints/src/casts/cast_slice_from_raw_parts.rs b/src/tools/clippy/clippy_lints/src/casts/cast_slice_from_raw_parts.rs new file mode 100644 index 000000000..284ef1659 --- /dev/null +++ b/src/tools/clippy/clippy_lints/src/casts/cast_slice_from_raw_parts.rs @@ -0,0 +1,63 @@ +use clippy_utils::diagnostics::span_lint_and_sugg; +use clippy_utils::source::snippet_with_applicability; +use clippy_utils::{match_def_path, meets_msrv, msrvs, paths}; +use if_chain::if_chain; +use rustc_errors::Applicability; +use rustc_hir::{def_id::DefId, Expr, ExprKind}; +use rustc_lint::LateContext; +use rustc_middle::ty::{self, Ty}; +use rustc_semver::RustcVersion; + +use super::CAST_SLICE_FROM_RAW_PARTS; + +enum RawPartsKind { + Immutable, + Mutable, +} + +fn raw_parts_kind(cx: &LateContext<'_>, did: DefId) -> Option<RawPartsKind> { + if match_def_path(cx, did, &paths::SLICE_FROM_RAW_PARTS) { + Some(RawPartsKind::Immutable) + } else if match_def_path(cx, did, &paths::SLICE_FROM_RAW_PARTS_MUT) { + Some(RawPartsKind::Mutable) + } else { + None + } +} + +pub(super) fn check( + cx: &LateContext<'_>, + expr: &Expr<'_>, + cast_expr: &Expr<'_>, + cast_to: Ty<'_>, + msrv: Option<RustcVersion>, +) { + if_chain! { + if meets_msrv(msrv, msrvs::PTR_SLICE_RAW_PARTS); + if let ty::RawPtr(ptrty) = cast_to.kind(); + if let ty::Slice(_) = ptrty.ty.kind(); + if let ExprKind::Call(fun, [ptr_arg, len_arg]) = cast_expr.peel_blocks().kind; + if let ExprKind::Path(ref qpath) = fun.kind; + if let Some(fun_def_id) = cx.qpath_res(qpath, fun.hir_id).opt_def_id(); + if let Some(rpk) = raw_parts_kind(cx, fun_def_id); + then { + let func = match rpk { + RawPartsKind::Immutable => "from_raw_parts", + RawPartsKind::Mutable => "from_raw_parts_mut" + }; + let span = expr.span; + let mut applicability = Applicability::MachineApplicable; + let ptr = snippet_with_applicability(cx, ptr_arg.span, "ptr", &mut applicability); + let len = snippet_with_applicability(cx, len_arg.span, "len", &mut applicability); + span_lint_and_sugg( + cx, + CAST_SLICE_FROM_RAW_PARTS, + span, + &format!("casting the result of `{func}` to {cast_to}"), + "replace with", + format!("core::ptr::slice_{func}({ptr}, {len})"), + applicability + ); + } + } +} diff --git a/src/tools/clippy/clippy_lints/src/casts/mod.rs b/src/tools/clippy/clippy_lints/src/casts/mod.rs index af3798a0c..cc5d346b9 100644 --- a/src/tools/clippy/clippy_lints/src/casts/mod.rs +++ b/src/tools/clippy/clippy_lints/src/casts/mod.rs @@ -1,3 +1,5 @@ +mod as_underscore; +mod borrow_as_ptr; mod cast_abs_to_unsigned; mod cast_enum_constructor; mod cast_lossless; @@ -8,6 +10,7 @@ mod cast_ptr_alignment; mod cast_ref_to_mut; mod cast_sign_loss; mod cast_slice_different_sizes; +mod cast_slice_from_raw_parts; mod char_lit_as_u8; mod fn_to_numeric_cast; mod fn_to_numeric_cast_any; @@ -16,7 +19,7 @@ mod ptr_as_ptr; mod unnecessary_cast; mod utils; -use clippy_utils::is_hir_ty_cfg_dependant; +use clippy_utils::{is_hir_ty_cfg_dependant, meets_msrv, msrvs}; use rustc_hir::{Expr, ExprKind}; use rustc_lint::{LateContext, LateLintPass, LintContext}; use rustc_middle::lint::in_external_macro; @@ -506,6 +509,93 @@ declare_clippy_lint! { "casting the result of `abs()` to an unsigned integer can panic" } +declare_clippy_lint! { + /// ### What it does + /// Check for the usage of `as _` conversion using inferred type. + /// + /// ### Why is this bad? + /// The conversion might include lossy conversion and dangerous cast that might go + /// undetected due to the type being inferred. + /// + /// The lint is allowed by default as using `_` is less wordy than always specifying the type. + /// + /// ### Example + /// ```rust + /// fn foo(n: usize) {} + /// let n: u16 = 256; + /// foo(n as _); + /// ``` + /// Use instead: + /// ```rust + /// fn foo(n: usize) {} + /// let n: u16 = 256; + /// foo(n as usize); + /// ``` + #[clippy::version = "1.63.0"] + pub AS_UNDERSCORE, + restriction, + "detects `as _` conversion" +} + +declare_clippy_lint! { + /// ### What it does + /// Checks for the usage of `&expr as *const T` or + /// `&mut expr as *mut T`, and suggest using `ptr::addr_of` or + /// `ptr::addr_of_mut` instead. + /// + /// ### Why is this bad? + /// This would improve readability and avoid creating a reference + /// that points to an uninitialized value or unaligned place. + /// Read the `ptr::addr_of` docs for more information. + /// + /// ### Example + /// ```rust + /// let val = 1; + /// let p = &val as *const i32; + /// + /// let mut val_mut = 1; + /// let p_mut = &mut val_mut as *mut i32; + /// ``` + /// Use instead: + /// ```rust + /// let val = 1; + /// let p = std::ptr::addr_of!(val); + /// + /// let mut val_mut = 1; + /// let p_mut = std::ptr::addr_of_mut!(val_mut); + /// ``` + #[clippy::version = "1.60.0"] + pub BORROW_AS_PTR, + pedantic, + "borrowing just to cast to a raw pointer" +} +declare_clippy_lint! { + /// ### What it does + /// Checks for a raw slice being cast to a slice pointer + /// + /// ### Why is this bad? + /// This can result in multiple `&mut` references to the same location when only a pointer is + /// required. + /// `ptr::slice_from_raw_parts` is a safe alternative that doesn't require + /// the same [safety requirements] to be upheld. + /// + /// ### Example + /// ```rust,ignore + /// let _: *const [u8] = std::slice::from_raw_parts(ptr, len) as *const _; + /// let _: *mut [u8] = std::slice::from_raw_parts_mut(ptr, len) as *mut _; + /// ``` + /// Use instead: + /// ```rust,ignore + /// let _: *const [u8] = std::ptr::slice_from_raw_parts(ptr, len); + /// let _: *mut [u8] = std::ptr::slice_from_raw_parts_mut(ptr, len); + /// ``` + /// [safety requirements]: https://doc.rust-lang.org/std/slice/fn.from_raw_parts.html#safety + #[clippy::version = "1.64.0"] + pub CAST_SLICE_FROM_RAW_PARTS, + suspicious, + "casting a slice created from a pointer and length to a slice pointer" +} + pub struct Casts { msrv: Option<RustcVersion>, } @@ -534,7 +624,10 @@ impl_lint_pass!(Casts => [ PTR_AS_PTR, CAST_ENUM_TRUNCATION, CAST_ENUM_CONSTRUCTOR, - CAST_ABS_TO_UNSIGNED + CAST_ABS_TO_UNSIGNED, + AS_UNDERSCORE, + BORROW_AS_PTR, + CAST_SLICE_FROM_RAW_PARTS ]); impl<'tcx> LateLintPass<'tcx> for Casts { @@ -547,8 +640,8 @@ impl<'tcx> LateLintPass<'tcx> for Casts { return; } - if let ExprKind::Cast(cast_expr, cast_to) = expr.kind { - if is_hir_ty_cfg_dependant(cx, cast_to) { + if let ExprKind::Cast(cast_expr, cast_to_hir) = expr.kind { + if is_hir_ty_cfg_dependant(cx, cast_to_hir) { return; } let (cast_from, cast_to) = ( @@ -559,7 +652,7 @@ impl<'tcx> LateLintPass<'tcx> for Casts { if unnecessary_cast::check(cx, expr, cast_expr, cast_from, cast_to) { return; } - + cast_slice_from_raw_parts::check(cx, expr, cast_expr, cast_to, self.msrv); fn_to_numeric_cast_any::check(cx, expr, cast_expr, cast_from, cast_to); fn_to_numeric_cast::check(cx, expr, cast_expr, cast_from, cast_to); fn_to_numeric_cast_with_truncation::check(cx, expr, cast_expr, cast_from, cast_to); @@ -575,6 +668,12 @@ impl<'tcx> LateLintPass<'tcx> for Casts { cast_lossless::check(cx, expr, cast_expr, cast_from, cast_to, self.msrv); cast_enum_constructor::check(cx, expr, cast_expr, cast_from); } + + as_underscore::check(cx, expr, cast_to_hir); + + if meets_msrv(self.msrv, msrvs::BORROW_AS_PTR) { + borrow_as_ptr::check(cx, expr, cast_expr, cast_to_hir); + } } cast_ref_to_mut::check(cx, expr); diff --git a/src/tools/clippy/clippy_lints/src/casts/unnecessary_cast.rs b/src/tools/clippy/clippy_lints/src/casts/unnecessary_cast.rs index fff7da8e3..19d2e6e1d 100644 --- a/src/tools/clippy/clippy_lints/src/casts/unnecessary_cast.rs +++ b/src/tools/clippy/clippy_lints/src/casts/unnecessary_cast.rs @@ -90,13 +90,20 @@ pub(super) fn check<'tcx>( fn lint_unnecessary_cast(cx: &LateContext<'_>, expr: &Expr<'_>, literal_str: &str, cast_from: Ty<'_>, cast_to: Ty<'_>) { let literal_kind_name = if cast_from.is_integral() { "integer" } else { "float" }; + let replaced_literal; + let matchless = if literal_str.contains(['(', ')']) { + replaced_literal = literal_str.replace(['(', ')'], ""); + &replaced_literal + } else { + literal_str + }; span_lint_and_sugg( cx, UNNECESSARY_CAST, expr.span, &format!("casting {} literal to `{}` is unnecessary", literal_kind_name, cast_to), "try", - format!("{}_{}", literal_str.trim_end_matches('.'), cast_to), + format!("{}_{}", matchless.trim_end_matches('.'), cast_to), Applicability::MachineApplicable, ); } |