diff options
| -rw-r--r-- | clippy_lints/src/transmute/transmute_ptr_to_ref.rs | 44 | ||||
| -rw-r--r-- | tests/ui/transmute_ptr_to_ref.fixed | 39 | ||||
| -rw-r--r-- | tests/ui/transmute_ptr_to_ref.rs | 39 | ||||
| -rw-r--r-- | tests/ui/transmute_ptr_to_ref.stderr | 54 |
4 files changed, 150 insertions, 26 deletions
diff --git a/clippy_lints/src/transmute/transmute_ptr_to_ref.rs b/clippy_lints/src/transmute/transmute_ptr_to_ref.rs index e58212fae15..e67ab6a73d2 100644 --- a/clippy_lints/src/transmute/transmute_ptr_to_ref.rs +++ b/clippy_lints/src/transmute/transmute_ptr_to_ref.rs @@ -28,16 +28,27 @@ pub(super) fn check<'tcx>( format!("transmute from a pointer type (`{from_ty}`) to a reference type (`{to_ty}`)"), |diag| { let arg = sugg::Sugg::hir(cx, arg, ".."); - let (deref, cast) = if *mutbl == Mutability::Mut { - ("&mut *", "*mut") - } else { - ("&*", "*const") + let (deref, cast) = match mutbl { + Mutability::Mut => ("&mut *", "*mut"), + Mutability::Not => ("&*", "*const"), }; let mut app = Applicability::MachineApplicable; let sugg = if let Some(ty) = get_explicit_type(path) { let ty_snip = snippet_with_applicability(cx, ty.span, "..", &mut app); - if msrv.meets(cx, msrvs::POINTER_CAST) { + if !to_ref_ty.is_sized(cx.tcx, cx.typing_env()) { + // We can't suggest `.cast()`, because that requires `to_ref_ty` to be Sized. + if from_ptr_ty.has_erased_regions() { + // We can't suggest `as *mut/const () as *mut/const to_ref_ty`, because the former is a + // thin pointer, whereas the latter is a wide pointer, due of its pointee, `to_ref_ty`, + // being !Sized. + // + // The only remaining option is be to skip `*mut/const ()`, but that might not be safe + // to do because of the erased regions in `from_ptr_ty`, so reduce the applicability. + app = Applicability::MaybeIncorrect; + } + sugg::make_unop(deref, arg.as_ty(format!("{cast} {ty_snip}"))).to_string() + } else if msrv.meets(cx, msrvs::POINTER_CAST) { format!("{deref}{}.cast::<{ty_snip}>()", arg.maybe_paren()) } else if from_ptr_ty.has_erased_regions() { sugg::make_unop(deref, arg.as_ty(format!("{cast} () as {cast} {ty_snip}"))).to_string() @@ -45,15 +56,22 @@ pub(super) fn check<'tcx>( sugg::make_unop(deref, arg.as_ty(format!("{cast} {ty_snip}"))).to_string() } } else if *from_ptr_ty == *to_ref_ty { - if from_ptr_ty.has_erased_regions() { - if msrv.meets(cx, msrvs::POINTER_CAST) { - format!("{deref}{}.cast::<{to_ref_ty}>()", arg.maybe_paren()) - } else { - sugg::make_unop(deref, arg.as_ty(format!("{cast} () as {cast} {to_ref_ty}"))) - .to_string() - } - } else { + if !from_ptr_ty.has_erased_regions() { sugg::make_unop(deref, arg).to_string() + } else if !to_ref_ty.is_sized(cx.tcx, cx.typing_env()) { + // 1. We can't suggest `.cast()`, because that requires `to_ref_ty` to be Sized. + // 2. We can't suggest `as *mut/const () as *mut/const to_ref_ty`, because the former is a + // thin pointer, whereas the latter is a wide pointer, due of its pointee, `to_ref_ty`, + // being !Sized. + // + // The only remaining option is be to skip `*mut/const ()`, but that might not be safe to do + // because of the erased regions in `from_ptr_ty`, so reduce the applicability. + app = Applicability::MaybeIncorrect; + sugg::make_unop(deref, arg.as_ty(format!("{cast} {to_ref_ty}"))).to_string() + } else if msrv.meets(cx, msrvs::POINTER_CAST) { + format!("{deref}{}.cast::<{to_ref_ty}>()", arg.maybe_paren()) + } else { + sugg::make_unop(deref, arg.as_ty(format!("{cast} () as {cast} {to_ref_ty}"))).to_string() } } else { sugg::make_unop(deref, arg.as_ty(format!("{cast} {to_ref_ty}"))).to_string() diff --git a/tests/ui/transmute_ptr_to_ref.fixed b/tests/ui/transmute_ptr_to_ref.fixed index 61e3ac2fe88..c130575df96 100644 --- a/tests/ui/transmute_ptr_to_ref.fixed +++ b/tests/ui/transmute_ptr_to_ref.fixed @@ -5,7 +5,7 @@ clippy::missing_transmute_annotations )] -unsafe fn _ptr_to_ref<T, U>(p: *const T, m: *mut T, o: *const U, om: *mut U) { +fn ptr_to_ref<T, U>(p: *const T, m: *mut T, o: *const U, om: *mut U) { unsafe { let _: &T = &*p; //~^ transmute_ptr_to_ref @@ -37,7 +37,7 @@ unsafe fn _ptr_to_ref<T, U>(p: *const T, m: *mut T, o: *const U, om: *mut U) { } } -fn _issue1231() { +fn issue1231() { struct Foo<'a, T> { bar: &'a T, } @@ -55,7 +55,7 @@ fn _issue1231() { //~^ transmute_ptr_to_ref } -unsafe fn _issue8924<'a, 'b, 'c>(x: *const &'a u32, y: *const &'b u32) -> &'c &'b u32 { +fn issue8924<'a, 'b, 'c>(x: *const &'a u32, y: *const &'b u32) -> &'c &'b u32 { unsafe { match 0 { 0 => &*x.cast::<&u32>(), @@ -71,7 +71,7 @@ unsafe fn _issue8924<'a, 'b, 'c>(x: *const &'a u32, y: *const &'b u32) -> &'c &' } #[clippy::msrv = "1.38"] -unsafe fn _meets_msrv<'a, 'b, 'c>(x: *const &'a u32) -> &'c &'b u32 { +fn meets_msrv<'a, 'b, 'c>(x: *const &'a u32) -> &'c &'b u32 { unsafe { let a = 0u32; let a = &a as *const u32; @@ -89,7 +89,7 @@ unsafe fn _meets_msrv<'a, 'b, 'c>(x: *const &'a u32) -> &'c &'b u32 { } #[clippy::msrv = "1.37"] -unsafe fn _under_msrv<'a, 'b, 'c>(x: *const &'a u32) -> &'c &'b u32 { +fn under_msrv<'a, 'b, 'c>(x: *const &'a u32) -> &'c &'b u32 { unsafe { let a = 0u32; let a = &a as *const u32; @@ -106,4 +106,33 @@ unsafe fn _under_msrv<'a, 'b, 'c>(x: *const &'a u32) -> &'c &'b u32 { } } +// handle DSTs +fn issue13357(ptr: *const [i32], s_ptr: *const &str, a_s_ptr: *const [&str]) { + unsafe { + // different types, without erased regions + let _ = &*(ptr as *const [u32]); + //~^ transmute_ptr_to_ref + let _: &[u32] = &*(ptr as *const [u32]); + //~^ transmute_ptr_to_ref + + // different types, with erased regions + let _ = &*(a_s_ptr as *const [&[u8]]); + //~^ transmute_ptr_to_ref + let _: &[&[u8]] = &*(a_s_ptr as *const [&[u8]]); + //~^ transmute_ptr_to_ref + + // same type, without erased regions + let _ = &*(ptr as *const [i32]); + //~^ transmute_ptr_to_ref + let _: &[i32] = &*ptr; + //~^ transmute_ptr_to_ref + + // same type, with erased regions + let _ = &*(a_s_ptr as *const [&str]); + //~^ transmute_ptr_to_ref + let _: &[&str] = &*(a_s_ptr as *const [&str]); + //~^ transmute_ptr_to_ref + } +} + fn main() {} diff --git a/tests/ui/transmute_ptr_to_ref.rs b/tests/ui/transmute_ptr_to_ref.rs index 48e2f527b55..f79d54234a2 100644 --- a/tests/ui/transmute_ptr_to_ref.rs +++ b/tests/ui/transmute_ptr_to_ref.rs @@ -5,7 +5,7 @@ clippy::missing_transmute_annotations )] -unsafe fn _ptr_to_ref<T, U>(p: *const T, m: *mut T, o: *const U, om: *mut U) { +fn ptr_to_ref<T, U>(p: *const T, m: *mut T, o: *const U, om: *mut U) { unsafe { let _: &T = std::mem::transmute(p); //~^ transmute_ptr_to_ref @@ -37,7 +37,7 @@ unsafe fn _ptr_to_ref<T, U>(p: *const T, m: *mut T, o: *const U, om: *mut U) { } } -fn _issue1231() { +fn issue1231() { struct Foo<'a, T> { bar: &'a T, } @@ -55,7 +55,7 @@ fn _issue1231() { //~^ transmute_ptr_to_ref } -unsafe fn _issue8924<'a, 'b, 'c>(x: *const &'a u32, y: *const &'b u32) -> &'c &'b u32 { +fn issue8924<'a, 'b, 'c>(x: *const &'a u32, y: *const &'b u32) -> &'c &'b u32 { unsafe { match 0 { 0 => std::mem::transmute(x), @@ -71,7 +71,7 @@ unsafe fn _issue8924<'a, 'b, 'c>(x: *const &'a u32, y: *const &'b u32) -> &'c &' } #[clippy::msrv = "1.38"] -unsafe fn _meets_msrv<'a, 'b, 'c>(x: *const &'a u32) -> &'c &'b u32 { +fn meets_msrv<'a, 'b, 'c>(x: *const &'a u32) -> &'c &'b u32 { unsafe { let a = 0u32; let a = &a as *const u32; @@ -89,7 +89,7 @@ unsafe fn _meets_msrv<'a, 'b, 'c>(x: *const &'a u32) -> &'c &'b u32 { } #[clippy::msrv = "1.37"] -unsafe fn _under_msrv<'a, 'b, 'c>(x: *const &'a u32) -> &'c &'b u32 { +fn under_msrv<'a, 'b, 'c>(x: *const &'a u32) -> &'c &'b u32 { unsafe { let a = 0u32; let a = &a as *const u32; @@ -106,4 +106,33 @@ unsafe fn _under_msrv<'a, 'b, 'c>(x: *const &'a u32) -> &'c &'b u32 { } } +// handle DSTs +fn issue13357(ptr: *const [i32], s_ptr: *const &str, a_s_ptr: *const [&str]) { + unsafe { + // different types, without erased regions + let _ = core::mem::transmute::<_, &[u32]>(ptr); + //~^ transmute_ptr_to_ref + let _: &[u32] = core::mem::transmute(ptr); + //~^ transmute_ptr_to_ref + + // different types, with erased regions + let _ = core::mem::transmute::<_, &[&[u8]]>(a_s_ptr); + //~^ transmute_ptr_to_ref + let _: &[&[u8]] = core::mem::transmute(a_s_ptr); + //~^ transmute_ptr_to_ref + + // same type, without erased regions + let _ = core::mem::transmute::<_, &[i32]>(ptr); + //~^ transmute_ptr_to_ref + let _: &[i32] = core::mem::transmute(ptr); + //~^ transmute_ptr_to_ref + + // same type, with erased regions + let _ = core::mem::transmute::<_, &[&str]>(a_s_ptr); + //~^ transmute_ptr_to_ref + let _: &[&str] = core::mem::transmute(a_s_ptr); + //~^ transmute_ptr_to_ref + } +} + fn main() {} diff --git a/tests/ui/transmute_ptr_to_ref.stderr b/tests/ui/transmute_ptr_to_ref.stderr index 7685c345c86..3f404d295fe 100644 --- a/tests/ui/transmute_ptr_to_ref.stderr +++ b/tests/ui/transmute_ptr_to_ref.stderr @@ -43,13 +43,13 @@ error: transmute from a pointer type (`*mut U`) to a reference type (`&T`) LL | let _: &T = std::mem::transmute(om); | ^^^^^^^^^^^^^^^^^^^^^^^ help: try: `&*(om as *const T)` -error: transmute from a pointer type (`*const i32`) to a reference type (`&_issue1231::Foo<'_, u8>`) +error: transmute from a pointer type (`*const i32`) to a reference type (`&issue1231::Foo<'_, u8>`) --> tests/ui/transmute_ptr_to_ref.rs:46:32 | LL | let _: &Foo<u8> = unsafe { std::mem::transmute::<_, &Foo<_>>(raw) }; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `&*raw.cast::<Foo<_>>()` -error: transmute from a pointer type (`*const i32`) to a reference type (`&_issue1231::Foo<'_, &u8>`) +error: transmute from a pointer type (`*const i32`) to a reference type (`&issue1231::Foo<'_, &u8>`) --> tests/ui/transmute_ptr_to_ref.rs:49:33 | LL | let _: &Foo<&u8> = unsafe { std::mem::transmute::<_, &Foo<&_>>(raw) }; @@ -133,5 +133,53 @@ error: transmute from a pointer type (`*const &u32`) to a reference type (`&&u32 LL | _ => std::mem::transmute::<_, &&'b u32>(x), | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `&*(x as *const () as *const &'b u32)` -error: aborting due to 22 previous errors +error: transmute from a pointer type (`*const [i32]`) to a reference type (`&[u32]`) + --> tests/ui/transmute_ptr_to_ref.rs:113:17 + | +LL | let _ = core::mem::transmute::<_, &[u32]>(ptr); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `&*(ptr as *const [u32])` + +error: transmute from a pointer type (`*const [i32]`) to a reference type (`&[u32]`) + --> tests/ui/transmute_ptr_to_ref.rs:115:25 + | +LL | let _: &[u32] = core::mem::transmute(ptr); + | ^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `&*(ptr as *const [u32])` + +error: transmute from a pointer type (`*const [&str]`) to a reference type (`&[&[u8]]`) + --> tests/ui/transmute_ptr_to_ref.rs:119:17 + | +LL | let _ = core::mem::transmute::<_, &[&[u8]]>(a_s_ptr); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `&*(a_s_ptr as *const [&[u8]])` + +error: transmute from a pointer type (`*const [&str]`) to a reference type (`&[&[u8]]`) + --> tests/ui/transmute_ptr_to_ref.rs:121:27 + | +LL | let _: &[&[u8]] = core::mem::transmute(a_s_ptr); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `&*(a_s_ptr as *const [&[u8]])` + +error: transmute from a pointer type (`*const [i32]`) to a reference type (`&[i32]`) + --> tests/ui/transmute_ptr_to_ref.rs:125:17 + | +LL | let _ = core::mem::transmute::<_, &[i32]>(ptr); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `&*(ptr as *const [i32])` + +error: transmute from a pointer type (`*const [i32]`) to a reference type (`&[i32]`) + --> tests/ui/transmute_ptr_to_ref.rs:127:25 + | +LL | let _: &[i32] = core::mem::transmute(ptr); + | ^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `&*ptr` + +error: transmute from a pointer type (`*const [&str]`) to a reference type (`&[&str]`) + --> tests/ui/transmute_ptr_to_ref.rs:131:17 + | +LL | let _ = core::mem::transmute::<_, &[&str]>(a_s_ptr); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `&*(a_s_ptr as *const [&str])` + +error: transmute from a pointer type (`*const [&str]`) to a reference type (`&[&str]`) + --> tests/ui/transmute_ptr_to_ref.rs:133:26 + | +LL | let _: &[&str] = core::mem::transmute(a_s_ptr); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `&*(a_s_ptr as *const [&str])` + +error: aborting due to 30 previous errors |