diff options
| -rw-r--r-- | CHANGELOG.md | 1 | ||||
| -rw-r--r-- | clippy_lints/src/lib.register_all.rs | 1 | ||||
| -rw-r--r-- | clippy_lints/src/lib.register_complexity.rs | 1 | ||||
| -rw-r--r-- | clippy_lints/src/lib.register_lints.rs | 1 | ||||
| -rw-r--r-- | clippy_lints/src/transmute/mod.rs | 25 | ||||
| -rw-r--r-- | clippy_lints/src/transmute/transmute_num_to_bytes.rs | 49 | ||||
| -rw-r--r-- | tests/ui/transmute.rs | 27 | ||||
| -rw-r--r-- | tests/ui/transmute.stderr | 92 |
8 files changed, 194 insertions, 3 deletions
diff --git a/CHANGELOG.md b/CHANGELOG.md index 13067e4e92a..4c0b1991fd4 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -3024,6 +3024,7 @@ Released 2018-09-13 [`transmute_int_to_bool`]: https://rust-lang.github.io/rust-clippy/master/index.html#transmute_int_to_bool [`transmute_int_to_char`]: https://rust-lang.github.io/rust-clippy/master/index.html#transmute_int_to_char [`transmute_int_to_float`]: https://rust-lang.github.io/rust-clippy/master/index.html#transmute_int_to_float +[`transmute_num_to_bytes`]: https://rust-lang.github.io/rust-clippy/master/index.html#transmute_num_to_bytes [`transmute_ptr_to_ptr`]: https://rust-lang.github.io/rust-clippy/master/index.html#transmute_ptr_to_ptr [`transmute_ptr_to_ref`]: https://rust-lang.github.io/rust-clippy/master/index.html#transmute_ptr_to_ref [`transmutes_expressible_as_ptr_casts`]: https://rust-lang.github.io/rust-clippy/master/index.html#transmutes_expressible_as_ptr_casts diff --git a/clippy_lints/src/lib.register_all.rs b/clippy_lints/src/lib.register_all.rs index 3e6e0244754..8d0a3e7423b 100644 --- a/clippy_lints/src/lib.register_all.rs +++ b/clippy_lints/src/lib.register_all.rs @@ -266,6 +266,7 @@ store.register_group(true, "clippy::all", Some("clippy_all"), vec![ LintId::of(transmute::TRANSMUTE_INT_TO_BOOL), LintId::of(transmute::TRANSMUTE_INT_TO_CHAR), LintId::of(transmute::TRANSMUTE_INT_TO_FLOAT), + LintId::of(transmute::TRANSMUTE_NUM_TO_BYTES), LintId::of(transmute::TRANSMUTE_PTR_TO_REF), LintId::of(transmute::UNSOUND_COLLECTION_TRANSMUTE), LintId::of(transmute::WRONG_TRANSMUTE), diff --git a/clippy_lints/src/lib.register_complexity.rs b/clippy_lints/src/lib.register_complexity.rs index 64b82fc0faa..c51341bdf0c 100644 --- a/clippy_lints/src/lib.register_complexity.rs +++ b/clippy_lints/src/lib.register_complexity.rs @@ -82,6 +82,7 @@ store.register_group(true, "clippy::complexity", Some("clippy_complexity"), vec! LintId::of(transmute::TRANSMUTE_INT_TO_BOOL), LintId::of(transmute::TRANSMUTE_INT_TO_CHAR), LintId::of(transmute::TRANSMUTE_INT_TO_FLOAT), + LintId::of(transmute::TRANSMUTE_NUM_TO_BYTES), LintId::of(transmute::TRANSMUTE_PTR_TO_REF), LintId::of(types::BORROWED_BOX), LintId::of(types::TYPE_COMPLEXITY), diff --git a/clippy_lints/src/lib.register_lints.rs b/clippy_lints/src/lib.register_lints.rs index 3c4b720671a..8d17317c38e 100644 --- a/clippy_lints/src/lib.register_lints.rs +++ b/clippy_lints/src/lib.register_lints.rs @@ -449,6 +449,7 @@ store.register_lints(&[ transmute::TRANSMUTE_INT_TO_BOOL, transmute::TRANSMUTE_INT_TO_CHAR, transmute::TRANSMUTE_INT_TO_FLOAT, + transmute::TRANSMUTE_NUM_TO_BYTES, transmute::TRANSMUTE_PTR_TO_PTR, transmute::TRANSMUTE_PTR_TO_REF, transmute::UNSOUND_COLLECTION_TRANSMUTE, diff --git a/clippy_lints/src/transmute/mod.rs b/clippy_lints/src/transmute/mod.rs index 33ec9c331ce..374999473a4 100644 --- a/clippy_lints/src/transmute/mod.rs +++ b/clippy_lints/src/transmute/mod.rs @@ -3,6 +3,7 @@ mod transmute_float_to_int; mod transmute_int_to_bool; mod transmute_int_to_char; mod transmute_int_to_float; +mod transmute_num_to_bytes; mod transmute_ptr_to_ptr; mod transmute_ptr_to_ref; mod transmute_ref_to_ref; @@ -262,6 +263,28 @@ declare_clippy_lint! { } declare_clippy_lint! { + /// # What it does + /// Checks for transmutes from a number to an array of `u8` + /// + /// ### Why this is bad? + /// Transmutes are dangerous and error-prone, whereas `to_ne_bytes` + /// is intuitive and safe. + /// + /// ### Example + /// ```rust + /// unsafe { + /// let x: [u8; 8] = std::mem::transmute(1i64); + /// } + /// + /// // should be + /// let x: [u8; 8] = 0i64.to_ne_bytes(); + /// ``` + pub TRANSMUTE_NUM_TO_BYTES, + complexity, + "transmutes from a number to an array of `u8`" +} + +declare_clippy_lint! { /// ### What it does /// Checks for transmutes from a pointer to a pointer, or /// from a reference to a reference. @@ -330,6 +353,7 @@ declare_lint_pass!(Transmute => [ TRANSMUTE_INT_TO_BOOL, TRANSMUTE_INT_TO_FLOAT, TRANSMUTE_FLOAT_TO_INT, + TRANSMUTE_NUM_TO_BYTES, UNSOUND_COLLECTION_TRANSMUTE, TRANSMUTES_EXPRESSIBLE_AS_PTR_CASTS, ]); @@ -365,6 +389,7 @@ impl<'tcx> LateLintPass<'tcx> for Transmute { linted |= transmute_int_to_bool::check(cx, e, from_ty, to_ty, args); linted |= transmute_int_to_float::check(cx, e, from_ty, to_ty, args, const_context); linted |= transmute_float_to_int::check(cx, e, from_ty, to_ty, args, const_context); + linted |= transmute_num_to_bytes::check(cx, e, from_ty, to_ty, args, const_context); linted |= unsound_collection_transmute::check(cx, e, from_ty, to_ty); if !linted { diff --git a/clippy_lints/src/transmute/transmute_num_to_bytes.rs b/clippy_lints/src/transmute/transmute_num_to_bytes.rs new file mode 100644 index 00000000000..dd5ded1c91a --- /dev/null +++ b/clippy_lints/src/transmute/transmute_num_to_bytes.rs @@ -0,0 +1,49 @@ +use super::TRANSMUTE_NUM_TO_BYTES; +use clippy_utils::diagnostics::span_lint_and_then; +use clippy_utils::sugg; +use rustc_errors::Applicability; +use rustc_hir::Expr; +use rustc_lint::LateContext; +use rustc_middle::ty::{self, Ty, UintTy}; + +/// Checks for `transmute_int_to_float` lint. +/// Returns `true` if it's triggered, otherwise returns `false`. +pub(super) fn check<'tcx>( + cx: &LateContext<'tcx>, + e: &'tcx Expr<'_>, + from_ty: Ty<'tcx>, + to_ty: Ty<'tcx>, + args: &'tcx [Expr<'_>], + const_context: bool, +) -> bool { + match (&from_ty.kind(), &to_ty.kind()) { + (ty::Int(_) | ty::Uint(_) | ty::Float(_), ty::Array(arr_ty, _)) => { + if !matches!(arr_ty.kind(), ty::Uint(UintTy::U8)) { + return false; + } + if matches!(from_ty.kind(), ty::Float(_)) && const_context { + // TODO: Remove when const_float_bits_conv is stabilized + // rust#72447 + return false; + } + + span_lint_and_then( + cx, + TRANSMUTE_NUM_TO_BYTES, + e.span, + &format!("transmute from a `{}` to a `{}`", from_ty, to_ty), + |diag| { + let arg = sugg::Sugg::hir(cx, &args[0], ".."); + diag.span_suggestion( + e.span, + "consider using `to_ne_bytes()`", + format!("{}.to_ne_bytes()", arg.to_string()), + Applicability::Unspecified, + ); + }, + ); + true + }, + _ => false, + } +} diff --git a/tests/ui/transmute.rs b/tests/ui/transmute.rs index bce4c81b78a..6a7037d8f38 100644 --- a/tests/ui/transmute.rs +++ b/tests/ui/transmute.rs @@ -103,6 +103,33 @@ mod int_to_float { } } +mod num_to_bytes { + fn test() { + unsafe { + let _: [u8; 1] = std::mem::transmute(0u8); + let _: [u8; 4] = std::mem::transmute(0u32); + let _: [u8; 16] = std::mem::transmute(0u128); + let _: [u8; 1] = std::mem::transmute(0i8); + let _: [u8; 4] = std::mem::transmute(0i32); + let _: [u8; 16] = std::mem::transmute(0i128); + let _: [u8; 4] = std::mem::transmute(0.0f32); + let _: [u8; 8] = std::mem::transmute(0.0f64); + } + } + const fn test_const() { + unsafe { + let _: [u8; 1] = std::mem::transmute(0u8); + let _: [u8; 4] = std::mem::transmute(0u32); + let _: [u8; 16] = std::mem::transmute(0u128); + let _: [u8; 1] = std::mem::transmute(0i8); + let _: [u8; 4] = std::mem::transmute(0i32); + let _: [u8; 16] = std::mem::transmute(0i128); + let _: [u8; 4] = std::mem::transmute(0.0f32); + let _: [u8; 8] = std::mem::transmute(0.0f64); + } + } +} + fn bytes_to_str(b: &[u8], mb: &mut [u8]) { let _: &str = unsafe { std::mem::transmute(b) }; let _: &mut str = unsafe { std::mem::transmute(mb) }; diff --git a/tests/ui/transmute.stderr b/tests/ui/transmute.stderr index e31accb982a..86537153e32 100644 --- a/tests/ui/transmute.stderr +++ b/tests/ui/transmute.stderr @@ -140,8 +140,94 @@ error: transmute from a `i64` to a `f64` LL | let _: f64 = unsafe { std::mem::transmute(0_i64) }; | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `f64::from_bits(0_i64 as u64)` +error: transmute from a `u8` to a `[u8; 1]` + --> $DIR/transmute.rs:109:30 + | +LL | let _: [u8; 1] = std::mem::transmute(0u8); + | ^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `to_ne_bytes()`: `0u8.to_ne_bytes()` + | + = note: `-D clippy::transmute-num-to-bytes` implied by `-D warnings` + +error: transmute from a `u32` to a `[u8; 4]` + --> $DIR/transmute.rs:110:30 + | +LL | let _: [u8; 4] = std::mem::transmute(0u32); + | ^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `to_ne_bytes()`: `0u32.to_ne_bytes()` + +error: transmute from a `u128` to a `[u8; 16]` + --> $DIR/transmute.rs:111:31 + | +LL | let _: [u8; 16] = std::mem::transmute(0u128); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `to_ne_bytes()`: `0u128.to_ne_bytes()` + +error: transmute from a `i8` to a `[u8; 1]` + --> $DIR/transmute.rs:112:30 + | +LL | let _: [u8; 1] = std::mem::transmute(0i8); + | ^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `to_ne_bytes()`: `0i8.to_ne_bytes()` + +error: transmute from a `i32` to a `[u8; 4]` + --> $DIR/transmute.rs:113:30 + | +LL | let _: [u8; 4] = std::mem::transmute(0i32); + | ^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `to_ne_bytes()`: `0i32.to_ne_bytes()` + +error: transmute from a `i128` to a `[u8; 16]` + --> $DIR/transmute.rs:114:31 + | +LL | let _: [u8; 16] = std::mem::transmute(0i128); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `to_ne_bytes()`: `0i128.to_ne_bytes()` + +error: transmute from a `f32` to a `[u8; 4]` + --> $DIR/transmute.rs:115:30 + | +LL | let _: [u8; 4] = std::mem::transmute(0.0f32); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `to_ne_bytes()`: `0.0f32.to_ne_bytes()` + +error: transmute from a `f64` to a `[u8; 8]` + --> $DIR/transmute.rs:116:30 + | +LL | let _: [u8; 8] = std::mem::transmute(0.0f64); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `to_ne_bytes()`: `0.0f64.to_ne_bytes()` + +error: transmute from a `u8` to a `[u8; 1]` + --> $DIR/transmute.rs:121:30 + | +LL | let _: [u8; 1] = std::mem::transmute(0u8); + | ^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `to_ne_bytes()`: `0u8.to_ne_bytes()` + +error: transmute from a `u32` to a `[u8; 4]` + --> $DIR/transmute.rs:122:30 + | +LL | let _: [u8; 4] = std::mem::transmute(0u32); + | ^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `to_ne_bytes()`: `0u32.to_ne_bytes()` + +error: transmute from a `u128` to a `[u8; 16]` + --> $DIR/transmute.rs:123:31 + | +LL | let _: [u8; 16] = std::mem::transmute(0u128); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `to_ne_bytes()`: `0u128.to_ne_bytes()` + +error: transmute from a `i8` to a `[u8; 1]` + --> $DIR/transmute.rs:124:30 + | +LL | let _: [u8; 1] = std::mem::transmute(0i8); + | ^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `to_ne_bytes()`: `0i8.to_ne_bytes()` + +error: transmute from a `i32` to a `[u8; 4]` + --> $DIR/transmute.rs:125:30 + | +LL | let _: [u8; 4] = std::mem::transmute(0i32); + | ^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `to_ne_bytes()`: `0i32.to_ne_bytes()` + +error: transmute from a `i128` to a `[u8; 16]` + --> $DIR/transmute.rs:126:31 + | +LL | let _: [u8; 16] = std::mem::transmute(0i128); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `to_ne_bytes()`: `0i128.to_ne_bytes()` + error: transmute from a `&[u8]` to a `&str` - --> $DIR/transmute.rs:107:28 + --> $DIR/transmute.rs:134:28 | LL | let _: &str = unsafe { std::mem::transmute(b) }; | ^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `std::str::from_utf8(b).unwrap()` @@ -149,10 +235,10 @@ LL | let _: &str = unsafe { std::mem::transmute(b) }; = note: `-D clippy::transmute-bytes-to-str` implied by `-D warnings` error: transmute from a `&mut [u8]` to a `&mut str` - --> $DIR/transmute.rs:108:32 + --> $DIR/transmute.rs:135:32 | LL | let _: &mut str = unsafe { std::mem::transmute(mb) }; | ^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `std::str::from_utf8_mut(mb).unwrap()` -error: aborting due to 24 previous errors +error: aborting due to 38 previous errors |