32 lines
1022 B
Rust
32 lines
1022 B
Rust
#![warn(clippy::cast_ref_to_mut)]
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#![allow(clippy::no_effect, clippy::borrow_as_ptr)]
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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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fn main() {
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let s = String::from("Hello");
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let a = &s;
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unsafe {
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let num = &3i32;
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let mut_num = &mut 3i32;
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// Should be warned against
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(*(a as *const _ as *mut String)).push_str(" world");
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*(a as *const _ as *mut _) = String::from("Replaced");
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*(a as *const _ as *mut String) += " world";
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// Shouldn't be warned against
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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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}
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