[rustc.git] / compiler / rustc_error_codes / src / error_codes / E0093.md

An unknown intrinsic function was declared.

Erroneous code example:

```compile_fail,E0093
#![feature(intrinsics)]
#![allow(internal_features)]

extern "rust-intrinsic" {
    fn foo(); // error: unrecognized intrinsic function: `foo`
}

fn main() {
    unsafe {
        foo();
    }
}
```

Please check you didn't make a mistake in the function's name. All intrinsic
functions are defined in `compiler/rustc_codegen_llvm/src/intrinsic.rs` and in
`library/core/src/intrinsics.rs` in the Rust source code. Example:

```
#![feature(intrinsics)]
#![allow(internal_features)]

extern "rust-intrinsic" {
    fn atomic_fence_seqcst(); // ok!
}

fn main() {
    unsafe {
        atomic_fence_seqcst();
    }
}
```
Commit	Line	Data
60c5eb7d XL	1	An unknown intrinsic function was declared.
	2
	3	Erroneous code example:
	4
	5	```compile_fail,E0093
	6	#![feature(intrinsics)]
add651ee	7	#![allow(internal_features)]
60c5eb7d XL	8
	9	extern "rust-intrinsic" {
	10	fn foo(); // error: unrecognized intrinsic function: `foo`
	11	}
	12
	13	fn main() {
	14	unsafe {
	15	foo();
	16	}
	17	}
	18	```
	19
	20	Please check you didn't make a mistake in the function's name. All intrinsic
1b1a35ee XL	21	functions are defined in `compiler/rustc_codegen_llvm/src/intrinsic.rs` and in
1b1a35ee XL	22	`library/core/src/intrinsics.rs` in the Rust source code. Example:
60c5eb7d XL	23
	24	```
	25	#![feature(intrinsics)]
add651ee	26	#![allow(internal_features)]
60c5eb7d XL	27
60c5eb7d XL	28	extern "rust-intrinsic" {
064997fb	29	fn atomic_fence_seqcst(); // ok!
60c5eb7d XL	30	}
	31
	32	fn main() {
	33	unsafe {
064997fb	34	atomic_fence_seqcst();
60c5eb7d XL	35	}
	36	}
	37	```