src/librustc_passes/diagnostics.rs

// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

#![allow(non_snake_case)]

register_long_diagnostics! {
E0016: r##"
Blocks in constants may only contain items (such as constant, function
definition, etc...) and a tail expression. Example:

```
const FOO: i32 = { let x = 0; x }; // 'x' isn't an item!
```

To avoid it, you have to replace the non-item object:

```
const FOO: i32 = { const X : i32 = 0; X };
```
"##,

E0022: r##"
Constant functions are not allowed to mutate anything. Thus, binding to an
argument with a mutable pattern is not allowed. For example,

```
const fn foo(mut x: u8) {
    // do stuff
}
```

is bad because the function body may not mutate `x`.

Remove any mutable bindings from the argument list to fix this error. In case
you need to mutate the argument, try lazily initializing a global variable
instead of using a `const fn`, or refactoring the code to a functional style to
avoid mutation if possible.
"##,
}

register_diagnostics! {
    E0472, // asm! is unsupported on this target
}