Skip to content

Allow inner lint attributes on block expressions #69703

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
wants to merge 1 commit into from
Closed

Allow inner lint attributes on block expressions #69703

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
9 changes: 9 additions & 0 deletions src/librustc_ast/attr/mod.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -177,6 +177,15 @@ impl Attribute {
matches
}

/// Checks if the attribute is a lint attribute (`allow`, `warn`, `deny`, or `forbid`).
pub fn is_lint(&self) -> bool {
if let Some(ident) = self.ident().map(Ident::as_str) {
ident == "allow" || ident == "warn" || ident == "deny" || ident == "forbid"
} else {
false
}
}

/// For a single-segment attribute, returns its name; otherwise, returns `None`.
pub fn ident(&self) -> Option<Ident> {
match self.kind {
Expand Down
6 changes: 4 additions & 2 deletions src/librustc_parse/config.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -9,7 +9,7 @@
//! [#64197]: https://github.com/rust-lang/rust/issues/64197

use crate::{parse_in, validate_attr};
use rustc_ast::ast::{self, AttrItem, Attribute, MetaItem};
use rustc_ast::ast::{self, AttrItem, AttrStyle, Attribute, MetaItem};
use rustc_ast::attr::HasAttrs;
use rustc_ast::mut_visit::*;
use rustc_ast::ptr::P;
Expand Down Expand Up @@ -389,7 +389,9 @@ impl<'a> StripUnconfigured<'a> {

/// If attributes are not allowed on expressions, emit an error for `attr`
pub fn maybe_emit_expr_attr_err(&self, attr: &Attribute) {
if !self.features.map(|features| features.stmt_expr_attributes).unwrap_or(true) {
if !self.features.map(|features| features.stmt_expr_attributes).unwrap_or(true)
&& !(attr.is_lint() && attr.style == AttrStyle::Inner)
{
let mut err = feature_err(
self.sess,
sym::stmt_expr_attributes,
Expand Down
6 changes: 5 additions & 1 deletion src/test/ui/lint-expr-stmt-attrs-for-early-lints.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,6 +1,5 @@
// run-pass

#![feature(stmt_expr_attributes)]
#![deny(unused_parens)]

// Tests that lint attributes on statements/expressions are
Expand All @@ -11,4 +10,9 @@ fn main() {
{
let _ = (9);
}

let _ = {
#![allow(unused_parens)]
let _ = (9);
};
}
11 changes: 11 additions & 0 deletions src/test/ui/stmt_expr_attrs_no_feature.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -16,6 +16,17 @@ fn main() {

}

let _ = {
// inner lint attributes are allowed on blocks
#![allow(unused_variables)]
#![warn(unused_variables)]
#![deny(unused_variables)]
#![forbid(unused_variables)]
#![rustc_dummy] //~ ERROR attributes on expressions are experimental
};

let _ = #[allow(unused_variables)] {}; //~ ERROR attributes on expressions are experimental

#[rustc_dummy]
5;

Expand Down
36 changes: 27 additions & 9 deletions src/test/ui/stmt_expr_attrs_no_feature.stderr
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -8,7 +8,25 @@ LL | #[rustfmt::skip]
= help: add `#![feature(stmt_expr_attributes)]` to the crate attributes to enable

error[E0658]: attributes on expressions are experimental
--> $DIR/stmt_expr_attrs_no_feature.rs:95:18
--> $DIR/stmt_expr_attrs_no_feature.rs:25:9
|
LL | #![rustc_dummy]
| ^^^^^^^^^^^^^^^
|
= note: see issue #15701 <https://github.com/rust-lang/rust/issues/15701> for more information
= help: add `#![feature(stmt_expr_attributes)]` to the crate attributes to enable

error[E0658]: attributes on expressions are experimental
--> $DIR/stmt_expr_attrs_no_feature.rs:28:13
|
LL | let _ = #[allow(unused_variables)] {};
| ^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: see issue #15701 <https://github.com/rust-lang/rust/issues/15701> for more information
= help: add `#![feature(stmt_expr_attributes)]` to the crate attributes to enable

error[E0658]: attributes on expressions are experimental
--> $DIR/stmt_expr_attrs_no_feature.rs:106:18
|
LL | fn y(a: [u8; #[rustc_dummy] 5]);
| ^^^^^^^^^^^^^^
Expand All @@ -17,7 +35,7 @@ LL | fn y(a: [u8; #[rustc_dummy] 5]);
= help: add `#![feature(stmt_expr_attributes)]` to the crate attributes to enable

error[E0658]: attributes on expressions are experimental
--> $DIR/stmt_expr_attrs_no_feature.rs:102:19
--> $DIR/stmt_expr_attrs_no_feature.rs:113:19
|
LL | const Y: u8 = #[rustc_dummy] 5;
| ^^^^^^^^^^^^^^
Expand All @@ -26,7 +44,7 @@ LL | const Y: u8 = #[rustc_dummy] 5;
= help: add `#![feature(stmt_expr_attributes)]` to the crate attributes to enable

error[E0658]: attributes on expressions are experimental
--> $DIR/stmt_expr_attrs_no_feature.rs:108:19
--> $DIR/stmt_expr_attrs_no_feature.rs:119:19
|
LL | const Y: [u8; #[rustc_dummy] 5];
| ^^^^^^^^^^^^^^
Expand All @@ -35,7 +53,7 @@ LL | const Y: [u8; #[rustc_dummy] 5];
= help: add `#![feature(stmt_expr_attributes)]` to the crate attributes to enable

error[E0658]: attributes on expressions are experimental
--> $DIR/stmt_expr_attrs_no_feature.rs:114:18
--> $DIR/stmt_expr_attrs_no_feature.rs:125:18
|
LL | field2: [u8; #[rustc_dummy] 5]
| ^^^^^^^^^^^^^^
Expand All @@ -44,7 +62,7 @@ LL | field2: [u8; #[rustc_dummy] 5]
= help: add `#![feature(stmt_expr_attributes)]` to the crate attributes to enable

error[E0658]: attributes on expressions are experimental
--> $DIR/stmt_expr_attrs_no_feature.rs:119:10
--> $DIR/stmt_expr_attrs_no_feature.rs:130:10
|
LL | [u8; #[rustc_dummy] 5]
| ^^^^^^^^^^^^^^
Expand All @@ -53,7 +71,7 @@ LL | [u8; #[rustc_dummy] 5]
= help: add `#![feature(stmt_expr_attributes)]` to the crate attributes to enable

error[E0658]: attributes on expressions are experimental
--> $DIR/stmt_expr_attrs_no_feature.rs:125:14
--> $DIR/stmt_expr_attrs_no_feature.rs:136:14
|
LL | [u8; #[rustc_dummy] 5]
| ^^^^^^^^^^^^^^
Expand All @@ -62,7 +80,7 @@ LL | [u8; #[rustc_dummy] 5]
= help: add `#![feature(stmt_expr_attributes)]` to the crate attributes to enable

error[E0658]: attributes on expressions are experimental
--> $DIR/stmt_expr_attrs_no_feature.rs:130:22
--> $DIR/stmt_expr_attrs_no_feature.rs:141:22
|
LL | field2: [u8; #[rustc_dummy] 5]
| ^^^^^^^^^^^^^^
Expand All @@ -71,14 +89,14 @@ LL | field2: [u8; #[rustc_dummy] 5]
= help: add `#![feature(stmt_expr_attributes)]` to the crate attributes to enable

error[E0658]: attributes on expressions are experimental
--> $DIR/stmt_expr_attrs_no_feature.rs:138:14
--> $DIR/stmt_expr_attrs_no_feature.rs:149:14
|
LL | 6 => #[rustc_dummy] (),
| ^^^^^^^^^^^^^^
|
= note: see issue #15701 <https://github.com/rust-lang/rust/issues/15701> for more information
= help: add `#![feature(stmt_expr_attributes)]` to the crate attributes to enable

error: aborting due to 9 previous errors
error: aborting due to 11 previous errors

For more information about this error, try `rustc --explain E0658`.