Merge #159

159: static mut transform: forward `#[cfg]` r=therealprof a=japaric

as reported in japaric/cortex-m-rtfm#110 the following code fails to compile

``` rust
 #[entry]
fn main() -> ! {
    #[cfg(something)]
    static mut FOO: u32 = 0; //~ ERROR cannot find value `FOO` in this scope
}
```

the issue is that the expansion of the static looks like this:

``` rust
let FOO = unsafe {
    #[cfg(never)]
    static mut FOO: u32 = 0;

    &mut FOO
};
```

so when the `#[cfg]` evals to false the static is gone but the `let FOO` is not
removed.

this PR forwards `#[cfg]` attributes to the `let` expression and fixes the error

``` rust
 #[cfg(never)] // <- added
let FOO = unsafe {
    #[cfg(never)]
    static mut FOO: u32 = 0;

    &mut FOO
};
```

Co-authored-by: Jorge Aparicio <jorge@japaric.io>

0 files changed, 0 insertions, 0 deletions