Add #[allow_internal_unstable] to track stability for macros better.
Unstable items used in a macro expansion will now always trigger
stability warnings, *unless* the unstable items are directly inside a
macro marked with `#[allow_internal_unstable]`. IOW, the compiler warns
unless the span of the unstable item is a subspan of the definition of a
macro marked with that attribute.
E.g.
#[allow_internal_unstable]
macro_rules! foo {
($e: expr) => {{
$e;
unstable(); // no warning
only_called_by_foo!();
}}
}
macro_rules! only_called_by_foo {
() => { unstable() } // warning
}
foo!(unstable()) // warning
The unstable inside `foo` is fine, due to the attribute. But the
`unstable` inside `only_called_by_foo` is not, since that macro doesn't
have the attribute, and the `unstable` passed into `foo` is also not
fine since it isn't contained in the macro itself (that is, even though
it is only used directly in the macro).
In the process this makes the stability tracking much more precise,
e.g. previously `println!("{}", unstable())` got no warning, but now it
does. As such, this is a bug fix that may cause [breaking-change]s.
The attribute is definitely feature gated, since it explicitly allows
side-stepping the feature gating system.
2015-02-28 21:09:28 -06:00
|
|
|
// 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.
|
|
|
|
|
|
|
|
// this has to be separate to internal-unstable.rs because these tests
|
|
|
|
// have error messages pointing deep into the internals of the
|
|
|
|
// cross-crate macros, and hence need to use error-pattern instead of
|
|
|
|
// the // ~ form.
|
|
|
|
|
|
|
|
// aux-build:internal_unstable.rs
|
|
|
|
// error-pattern:use of unstable library feature 'function'
|
|
|
|
// error-pattern:use of unstable library feature 'struct_field'
|
2015-04-03 22:22:36 -05:00
|
|
|
// error-pattern:use of unstable library feature 'method'
|
|
|
|
// error-pattern:use of unstable library feature 'struct2_field'
|
Add #[allow_internal_unstable] to track stability for macros better.
Unstable items used in a macro expansion will now always trigger
stability warnings, *unless* the unstable items are directly inside a
macro marked with `#[allow_internal_unstable]`. IOW, the compiler warns
unless the span of the unstable item is a subspan of the definition of a
macro marked with that attribute.
E.g.
#[allow_internal_unstable]
macro_rules! foo {
($e: expr) => {{
$e;
unstable(); // no warning
only_called_by_foo!();
}}
}
macro_rules! only_called_by_foo {
() => { unstable() } // warning
}
foo!(unstable()) // warning
The unstable inside `foo` is fine, due to the attribute. But the
`unstable` inside `only_called_by_foo` is not, since that macro doesn't
have the attribute, and the `unstable` passed into `foo` is also not
fine since it isn't contained in the macro itself (that is, even though
it is only used directly in the macro).
In the process this makes the stability tracking much more precise,
e.g. previously `println!("{}", unstable())` got no warning, but now it
does. As such, this is a bug fix that may cause [breaking-change]s.
The attribute is definitely feature gated, since it explicitly allows
side-stepping the feature gating system.
2015-02-28 21:09:28 -06:00
|
|
|
|
|
|
|
#[macro_use]
|
|
|
|
extern crate internal_unstable;
|
|
|
|
|
|
|
|
fn main() {
|
|
|
|
call_unstable_noallow!();
|
|
|
|
|
|
|
|
construct_unstable_noallow!(0);
|
2015-04-03 22:22:36 -05:00
|
|
|
|
|
|
|
|x: internal_unstable::Foo| { call_method_noallow!(x) };
|
|
|
|
|
|
|
|
|x: internal_unstable::Bar| { access_field_noallow!(x) };
|
Add #[allow_internal_unstable] to track stability for macros better.
Unstable items used in a macro expansion will now always trigger
stability warnings, *unless* the unstable items are directly inside a
macro marked with `#[allow_internal_unstable]`. IOW, the compiler warns
unless the span of the unstable item is a subspan of the definition of a
macro marked with that attribute.
E.g.
#[allow_internal_unstable]
macro_rules! foo {
($e: expr) => {{
$e;
unstable(); // no warning
only_called_by_foo!();
}}
}
macro_rules! only_called_by_foo {
() => { unstable() } // warning
}
foo!(unstable()) // warning
The unstable inside `foo` is fine, due to the attribute. But the
`unstable` inside `only_called_by_foo` is not, since that macro doesn't
have the attribute, and the `unstable` passed into `foo` is also not
fine since it isn't contained in the macro itself (that is, even though
it is only used directly in the macro).
In the process this makes the stability tracking much more precise,
e.g. previously `println!("{}", unstable())` got no warning, but now it
does. As such, this is a bug fix that may cause [breaking-change]s.
The attribute is definitely feature gated, since it explicitly allows
side-stepping the feature gating system.
2015-02-28 21:09:28 -06:00
|
|
|
}
|