| #![allow(dead_code)] |
| |
| extern crate core; |
| |
| use std::mem::transmute as my_transmute; |
| use std::vec::Vec as MyVec; |
| |
| fn my_int() -> Usize { |
| Usize(42) |
| } |
| |
| fn my_vec() -> MyVec<i32> { |
| vec![] |
| } |
| |
| #[allow(clippy::needless_lifetimes, clippy::transmute_ptr_to_ptr)] |
| #[warn(clippy::useless_transmute)] |
| unsafe fn _generic<'a, T, U: 'a>(t: &'a T) { |
| let _: &'a T = core::intrinsics::transmute(t); |
| |
| let _: &'a U = core::intrinsics::transmute(t); |
| |
| let _: *const T = core::intrinsics::transmute(t); |
| |
| let _: *mut T = core::intrinsics::transmute(t); |
| |
| let _: *const U = core::intrinsics::transmute(t); |
| } |
| |
| #[warn(clippy::transmute_ptr_to_ref)] |
| unsafe fn _ptr_to_ref<T, U>(p: *const T, m: *mut T, o: *const U, om: *mut U) { |
| let _: &T = std::mem::transmute(p); |
| let _: &T = &*p; |
| |
| let _: &mut T = std::mem::transmute(m); |
| let _: &mut T = &mut *m; |
| |
| let _: &T = std::mem::transmute(m); |
| let _: &T = &*m; |
| |
| let _: &mut T = std::mem::transmute(p as *mut T); |
| let _ = &mut *(p as *mut T); |
| |
| let _: &T = std::mem::transmute(o); |
| let _: &T = &*(o as *const T); |
| |
| let _: &mut T = std::mem::transmute(om); |
| let _: &mut T = &mut *(om as *mut T); |
| |
| let _: &T = std::mem::transmute(om); |
| let _: &T = &*(om as *const T); |
| } |
| |
| #[warn(clippy::transmute_ptr_to_ref)] |
| fn issue1231() { |
| struct Foo<'a, T> { |
| bar: &'a T, |
| } |
| |
| let raw = 42 as *const i32; |
| let _: &Foo<u8> = unsafe { std::mem::transmute::<_, &Foo<_>>(raw) }; |
| |
| let _: &Foo<&u8> = unsafe { std::mem::transmute::<_, &Foo<&_>>(raw) }; |
| |
| type Bar<'a> = &'a u8; |
| let raw = 42 as *const i32; |
| unsafe { std::mem::transmute::<_, Bar>(raw) }; |
| } |
| |
| #[warn(clippy::useless_transmute)] |
| fn useless() { |
| unsafe { |
| let _: Vec<i32> = core::intrinsics::transmute(my_vec()); |
| |
| let _: Vec<i32> = core::mem::transmute(my_vec()); |
| |
| let _: Vec<i32> = std::intrinsics::transmute(my_vec()); |
| |
| let _: Vec<i32> = std::mem::transmute(my_vec()); |
| |
| let _: Vec<i32> = my_transmute(my_vec()); |
| |
| let _: Vec<u32> = core::intrinsics::transmute(my_vec()); |
| let _: Vec<u32> = core::mem::transmute(my_vec()); |
| let _: Vec<u32> = std::intrinsics::transmute(my_vec()); |
| let _: Vec<u32> = std::mem::transmute(my_vec()); |
| let _: Vec<u32> = my_transmute(my_vec()); |
| |
| let _: *const usize = std::mem::transmute(5_isize); |
| |
| let _ = 5_isize as *const usize; |
| |
| let _: *const usize = std::mem::transmute(1 + 1usize); |
| |
| let _ = (1 + 1_usize) as *const usize; |
| } |
| } |
| |
| struct Usize(usize); |
| |
| #[warn(clippy::crosspointer_transmute)] |
| fn crosspointer() { |
| let mut int: Usize = Usize(0); |
| let int_const_ptr: *const Usize = &int as *const Usize; |
| let int_mut_ptr: *mut Usize = &mut int as *mut Usize; |
| |
| unsafe { |
| let _: Usize = core::intrinsics::transmute(int_const_ptr); |
| |
| let _: Usize = core::intrinsics::transmute(int_mut_ptr); |
| |
| let _: *const Usize = core::intrinsics::transmute(my_int()); |
| |
| let _: *mut Usize = core::intrinsics::transmute(my_int()); |
| } |
| } |
| |
| #[warn(clippy::transmute_int_to_char)] |
| fn int_to_char() { |
| let _: char = unsafe { std::mem::transmute(0_u32) }; |
| let _: char = unsafe { std::mem::transmute(0_i32) }; |
| } |
| |
| #[warn(clippy::transmute_int_to_bool)] |
| fn int_to_bool() { |
| let _: bool = unsafe { std::mem::transmute(0_u8) }; |
| } |
| |
| #[warn(clippy::transmute_int_to_float)] |
| fn int_to_float() { |
| let _: f32 = unsafe { std::mem::transmute(0_u32) }; |
| let _: f32 = unsafe { std::mem::transmute(0_i32) }; |
| } |
| |
| fn bytes_to_str(b: &[u8], mb: &mut [u8]) { |
| let _: &str = unsafe { std::mem::transmute(b) }; |
| let _: &mut str = unsafe { std::mem::transmute(mb) }; |
| } |
| |
| // Make sure we can modify lifetimes, which is one of the recommended uses |
| // of transmute |
| |
| // Make sure we can do static lifetime transmutes |
| #[warn(clippy::transmute_ptr_to_ptr)] |
| unsafe fn transmute_lifetime_to_static<'a, T>(t: &'a T) -> &'static T { |
| std::mem::transmute::<&'a T, &'static T>(t) |
| } |
| |
| // Make sure we can do non-static lifetime transmutes |
| #[warn(clippy::transmute_ptr_to_ptr)] |
| unsafe fn transmute_lifetime<'a, 'b, T>(t: &'a T, u: &'b T) -> &'b T { |
| std::mem::transmute::<&'a T, &'b T>(t) |
| } |
| |
| struct LifetimeParam<'a> { |
| s: &'a str, |
| } |
| |
| struct GenericParam<T> { |
| t: T, |
| } |
| |
| #[warn(clippy::transmute_ptr_to_ptr)] |
| fn transmute_ptr_to_ptr() { |
| let ptr = &1u32 as *const u32; |
| let mut_ptr = &mut 1u32 as *mut u32; |
| unsafe { |
| // pointer-to-pointer transmutes; bad |
| let _: *const f32 = std::mem::transmute(ptr); |
| let _: *mut f32 = std::mem::transmute(mut_ptr); |
| // ref-ref transmutes; bad |
| let _: &f32 = std::mem::transmute(&1u32); |
| let _: &f64 = std::mem::transmute(&1f32); |
| // ^ this test is here because both f32 and f64 are the same TypeVariant, but they are not |
| // the same type |
| let _: &mut f32 = std::mem::transmute(&mut 1u32); |
| let _: &GenericParam<f32> = std::mem::transmute(&GenericParam { t: 1u32 }); |
| } |
| |
| // these are recommendations for solving the above; if these lint we need to update |
| // those suggestions |
| let _ = ptr as *const f32; |
| let _ = mut_ptr as *mut f32; |
| let _ = unsafe { &*(&1u32 as *const u32 as *const f32) }; |
| let _ = unsafe { &mut *(&mut 1u32 as *mut u32 as *mut f32) }; |
| |
| // transmute internal lifetimes, should not lint |
| let s = "hello world".to_owned(); |
| let lp = LifetimeParam { s: &s }; |
| let _: &LifetimeParam<'static> = unsafe { std::mem::transmute(&lp) }; |
| let _: &GenericParam<&LifetimeParam<'static>> = unsafe { std::mem::transmute(&GenericParam { t: &lp }) }; |
| } |
| |
| fn main() {} |