rust/clippy_lints/src/attrs/mixed_attributes_style.rs

86 lines
2.7 KiB
Rust

use super::MIXED_ATTRIBUTES_STYLE;
use clippy_utils::diagnostics::span_lint;
use rustc_ast::{AttrKind, AttrStyle, Attribute};
use rustc_data_structures::fx::FxHashSet;
use rustc_data_structures::sync::Lrc;
use rustc_lint::{LateContext, LintContext};
use rustc_span::source_map::SourceMap;
use rustc_span::{SourceFile, Span, Symbol};
#[derive(Hash, PartialEq, Eq)]
enum SimpleAttrKind {
Doc,
/// A normal attribute, with its name symbols.
Normal(Vec<Symbol>),
}
impl From<&AttrKind> for SimpleAttrKind {
fn from(value: &AttrKind) -> Self {
match value {
AttrKind::Normal(attr) => {
let path_symbols = attr
.item
.path
.segments
.iter()
.map(|seg| seg.ident.name)
.collect::<Vec<_>>();
Self::Normal(path_symbols)
},
AttrKind::DocComment(..) => Self::Doc,
}
}
}
pub(super) fn check(cx: &LateContext<'_>, item_span: Span, attrs: &[Attribute]) {
let mut inner_attr_kind: FxHashSet<SimpleAttrKind> = FxHashSet::default();
let mut outer_attr_kind: FxHashSet<SimpleAttrKind> = FxHashSet::default();
let source_map = cx.sess().source_map();
let item_src = source_map.lookup_source_file(item_span.lo());
for attr in attrs {
if attr.span.from_expansion() || !attr_in_same_src_as_item(source_map, &item_src, attr.span) {
continue;
}
let kind: SimpleAttrKind = (&attr.kind).into();
match attr.style {
AttrStyle::Inner => {
if outer_attr_kind.contains(&kind) {
lint_mixed_attrs(cx, attrs);
return;
}
inner_attr_kind.insert(kind);
},
AttrStyle::Outer => {
if inner_attr_kind.contains(&kind) {
lint_mixed_attrs(cx, attrs);
return;
}
outer_attr_kind.insert(kind);
},
};
}
}
fn lint_mixed_attrs(cx: &LateContext<'_>, attrs: &[Attribute]) {
let mut attrs_iter = attrs.iter().filter(|attr| !attr.span.from_expansion());
let span = if let (Some(first), Some(last)) = (attrs_iter.next(), attrs_iter.last()) {
first.span.with_hi(last.span.hi())
} else {
return;
};
span_lint(
cx,
MIXED_ATTRIBUTES_STYLE,
span,
"item has both inner and outer attributes",
);
}
fn attr_in_same_src_as_item(source_map: &SourceMap, item_src: &Lrc<SourceFile>, attr_span: Span) -> bool {
let attr_src = source_map.lookup_source_file(attr_span.lo());
Lrc::ptr_eq(item_src, &attr_src)
}