77 lines
2.7 KiB
Rust
77 lines
2.7 KiB
Rust
// check-fail
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#![feature(ptr_from_ref)]
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extern "C" {
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// N.B., mutability can be easily incorrect in FFI calls -- as
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// in C, the default is mutable pointers.
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fn ffi(c: *mut u8);
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fn int_ffi(c: *mut i32);
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}
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unsafe fn ref_to_mut() {
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let num = &3i32;
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let _num = &mut *(num as *const i32 as *mut i32);
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//~^ ERROR casting `&T` to `&mut T` is undefined behavior
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let _num = &mut *(num as *const i32).cast_mut();
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//~^ ERROR casting `&T` to `&mut T` is undefined behavior
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let _num = &mut *std::ptr::from_ref(num).cast_mut();
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//~^ ERROR casting `&T` to `&mut T` is undefined behavior
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let _num = &mut *std::ptr::from_ref({ num }).cast_mut();
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//~^ ERROR casting `&T` to `&mut T` is undefined behavior
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let _num = &mut *{ std::ptr::from_ref(num) }.cast_mut();
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//~^ ERROR casting `&T` to `&mut T` is undefined behavior
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let _num = &mut *(std::ptr::from_ref({ num }) as *mut i32);
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//~^ ERROR casting `&T` to `&mut T` is undefined behavior
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let _num = &mut *std::mem::transmute::<_, *mut i32>(num);
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//~^ ERROR casting `&T` to `&mut T` is undefined behavior
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let deferred = num as *const i32 as *mut i32;
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let _num = &mut *deferred;
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//~^ ERROR casting `&T` to `&mut T` is undefined behavior
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}
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unsafe fn assign_to_ref() {
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let s = String::from("Hello");
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let a = &s;
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let num = &3i32;
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*(a as *const _ as *mut _) = String::from("Replaced");
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//~^ ERROR assigning to `&T` is undefined behavior
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*(a as *const _ as *mut String) += " world";
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//~^ ERROR assigning to `&T` is undefined behavior
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*std::ptr::from_ref(num).cast_mut() += 1;
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//~^ ERROR assigning to `&T` is undefined behavior
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*std::ptr::from_ref({ num }).cast_mut() += 1;
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//~^ ERROR assigning to `&T` is undefined behavior
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*{ std::ptr::from_ref(num) }.cast_mut() += 1;
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//~^ ERROR assigning to `&T` is undefined behavior
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*(std::ptr::from_ref({ num }) as *mut i32) += 1;
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//~^ ERROR assigning to `&T` is undefined behavior
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*std::mem::transmute::<_, *mut i32>(num) += 1;
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//~^ ERROR assigning to `&T` is undefined behavior
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let value = num as *const i32 as *mut i32;
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*value = 1;
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//~^ ERROR assigning to `&T` is undefined behavior
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}
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unsafe fn no_warn() {
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let num = &3i32;
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let mut_num = &mut 3i32;
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let a = &String::from("ffi");
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*(num as *const i32 as *mut i32);
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println!("{}", *(num as *const _ as *const i16));
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println!("{}", *(mut_num as *mut _ as *mut i16));
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ffi(a.as_ptr() as *mut _);
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int_ffi(num as *const _ as *mut _);
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int_ffi(&3 as *const _ as *mut _);
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let mut value = 3;
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let value: *const i32 = &mut value;
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*(value as *const i16 as *mut i16) = 42;
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}
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fn main() {}
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