rust/clippy_lints/src/inline_fn_without_body.rs
Ryan Cumming 7467b83377 Suggest removing inline attributes
This adds a `suggest_remove_item` helper that will remove an item and
all trailing whitespace. This should handle both attributes on the same
line as the function and on a separate line; the function takes the
position of the original attribute.
2018-01-18 20:02:42 +11:00

66 lines
1.7 KiB
Rust

//! checks for `#[inline]` on trait methods without bodies
use rustc::lint::*;
use rustc::hir::*;
use syntax::ast::{Attribute, Name};
use utils::span_lint_and_then;
use utils::sugg::DiagnosticBuilderExt;
/// **What it does:** Checks for `#[inline]` on trait methods without bodies
///
/// **Why is this bad?** Only implementations of trait methods may be inlined.
/// The inline attribute is ignored for trait methods without bodies.
///
/// **Known problems:** None.
///
/// **Example:**
/// ```rust
/// trait Animal {
/// #[inline]
/// fn name(&self) -> &'static str;
/// }
/// ```
declare_lint! {
pub INLINE_FN_WITHOUT_BODY,
Warn,
"use of `#[inline]` on trait methods without bodies"
}
#[derive(Copy, Clone)]
pub struct Pass;
impl LintPass for Pass {
fn get_lints(&self) -> LintArray {
lint_array!(INLINE_FN_WITHOUT_BODY)
}
}
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {
fn check_trait_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx TraitItem) {
match item.node {
TraitItemKind::Method(_, TraitMethod::Required(_)) => {
check_attrs(cx, &item.name, &item.attrs);
},
_ => {},
}
}
}
fn check_attrs(cx: &LateContext, name: &Name, attrs: &[Attribute]) {
for attr in attrs {
if attr.name().map_or(true, |n| n != "inline") {
continue;
}
span_lint_and_then(
cx,
INLINE_FN_WITHOUT_BODY,
attr.span,
&format!("use of `#[inline]` on trait method `{}` which has no body", name),
|db| {
db.suggest_remove_item(cx, attr.span, "remove");
},
);
}
}