Merge pull request from oli-obk/useless_lint_attributes

disallow lint attributes on `use` and `extern crate` items
This commit is contained in:
Oliver Schneider 2016-08-17 12:23:31 +02:00 committed by GitHub
commit e5e2db7113
5 changed files with 58 additions and 3 deletions

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@ -304,6 +304,7 @@ All notable changes to this project will be documented in this file.
[`unused_lifetimes`]: https://github.com/Manishearth/rust-clippy/wiki#unused_lifetimes
[`use_debug`]: https://github.com/Manishearth/rust-clippy/wiki#use_debug
[`used_underscore_binding`]: https://github.com/Manishearth/rust-clippy/wiki#used_underscore_binding
[`useless_attribute`]: https://github.com/Manishearth/rust-clippy/wiki#useless_attribute
[`useless_format`]: https://github.com/Manishearth/rust-clippy/wiki#useless_format
[`useless_let_if_seq`]: https://github.com/Manishearth/rust-clippy/wiki#useless_let_if_seq
[`useless_transmute`]: https://github.com/Manishearth/rust-clippy/wiki#useless_transmute

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@ -17,7 +17,7 @@ Table of contents:
## Lints
There are 165 lints included in this crate:
There are 166 lints included in this crate:
name | default | triggers on
---------------------------------------------------------------------------------------------------------------------|---------|----------------------------------------------------------------------------------------------------------------------------------
@ -175,6 +175,7 @@ name
[unused_lifetimes](https://github.com/Manishearth/rust-clippy/wiki#unused_lifetimes) | warn | unused lifetimes in function definitions
[use_debug](https://github.com/Manishearth/rust-clippy/wiki#use_debug) | allow | use of `Debug`-based formatting
[used_underscore_binding](https://github.com/Manishearth/rust-clippy/wiki#used_underscore_binding) | allow | using a binding which is prefixed with an underscore
[useless_attribute](https://github.com/Manishearth/rust-clippy/wiki#useless_attribute) | warn | use of lint attributes on `extern crate` items
[useless_format](https://github.com/Manishearth/rust-clippy/wiki#useless_format) | warn | useless use of `format!`
[useless_let_if_seq](https://github.com/Manishearth/rust-clippy/wiki#useless_let_if_seq) | warn | unidiomatic `let mut` declaration followed by initialization in `if`
[useless_transmute](https://github.com/Manishearth/rust-clippy/wiki#useless_transmute) | warn | transmutes that have the same to and from types or could be a cast/coercion

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@ -6,7 +6,7 @@ use rustc::hir::*;
use semver::Version;
use syntax::ast::{Attribute, Lit, LitKind, MetaItemKind};
use syntax::codemap::Span;
use utils::{in_macro, match_path, span_lint};
use utils::{in_macro, match_path, span_lint, span_lint_and_then, snippet_opt};
use utils::paths;
/// **What it does:** Checks for items annotated with `#[inline(always)]`,
@ -35,6 +35,25 @@ declare_lint! {
"use of `#[inline(always)]`"
}
/// **What it does:** Checks for `extern crate` and `use` items annotated with lint attributes
///
/// **Why is this bad?** Lint attributes have no effect on crate imports. Most likely a `!` was forgotten
///
/// **Known problems:** Technically one might allow `unused_import` on a `use` item, but it's easier to remove the unused item.
///
/// **Example:**
/// ```rust
/// #[deny(dead_code)]
/// extern crate foo;
/// #[allow(unused_import)]
/// use foo::bar;
/// ```
declare_lint! {
pub USELESS_ATTRIBUTE,
Warn,
"use of lint attributes on `extern crate` items"
}
/// **What it does:** Checks for `#[deprecated]` annotations with a `since`
/// field that is not a valid semantic version.
///
@ -59,7 +78,7 @@ pub struct AttrPass;
impl LintPass for AttrPass {
fn get_lints(&self) -> LintArray {
lint_array!(INLINE_ALWAYS, DEPRECATED_SEMVER)
lint_array!(INLINE_ALWAYS, DEPRECATED_SEMVER, USELESS_ATTRIBUTE)
}
}
@ -83,6 +102,29 @@ impl LateLintPass for AttrPass {
if is_relevant_item(item) {
check_attrs(cx, item.span, &item.name, &item.attrs)
}
match item.node {
ItemExternCrate(_) |
ItemUse(_) => {
for attr in &item.attrs {
if let MetaItemKind::List(ref name, _) = attr.node.value.node {
match &**name {
"allow" | "warn" | "deny" | "forbid" => {
span_lint_and_then(cx, USELESS_ATTRIBUTE, attr.span,
"useless lint attribute",
|db| {
if let Some(mut sugg) = snippet_opt(cx, attr.span) {
sugg.insert(1, '!');
db.span_suggestion(attr.span, "if you just forgot a `!`, use", sugg);
}
});
},
_ => {},
}
}
}
},
_ => {},
}
}
fn check_impl_item(&mut self, cx: &LateContext, item: &ImplItem) {

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@ -308,6 +308,7 @@ pub fn register_plugins(reg: &mut rustc_plugin::Registry) {
assign_ops::MISREFACTORED_ASSIGN_OP,
attrs::DEPRECATED_SEMVER,
attrs::INLINE_ALWAYS,
attrs::USELESS_ATTRIBUTE,
bit_mask::BAD_BIT_MASK,
bit_mask::INEFFECTIVE_BIT_MASK,
blacklisted_name::BLACKLISTED_NAME,

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@ -0,0 +1,10 @@
#![feature(plugin)]
#![plugin(clippy)]
#![deny(useless_attribute)]
#[allow(dead_code)] //~ ERROR useless lint attribute
//~| HELP if you just forgot a `!`, use
//~| SUGGESTION #![allow(dead_code)]
extern crate clippy_lints;
fn main() {}